The James Webb Space Telescope has passed the final mission analysis review(asc-csa.gc.ca)
asc-csa.gc.ca
The James Webb Space Telescope has passed the final mission analysis review
https://www.asc-csa.gc.ca/eng/satellites/jwst/news.asp
298 comments
> This documentary was produced by Northrop Grumman Corporation -- the builders of JWST under a NASA contract.
Is it promotional material?
Is it promotional material?
Propaganda
Considering that they themselves made the telescope, do you consider all forms of self expression propoganda?
> self expression
This isn't art. And yes, I don't trust corporate press releases (though I'm not sure "propaganda" is the right term); do you?
This isn't art. And yes, I don't trust corporate press releases (though I'm not sure "propaganda" is the right term); do you?
I agree that one needs to be critical or corporate videos.
I've watched the video and it is appealing to feelings and has very little technical details.
It impresses by outlining the size and some of the complexity but nothing more. It does not give dates, cost or other numbers. I liked it but would like a much more technical documentation too.
It impresses by outlining the size and some of the complexity but nothing more. It does not give dates, cost or other numbers. I liked it but would like a much more technical documentation too.
It's my personal belief that these massive R&D space telescope programs are nearing their end. Computational approaches among multiple sensors, combined with good 'ol factory mass manufacturing powered by low-cost reusable launch technology allows for the money spent on one-shot programs like this to be spent and allocated in radical different ways.
Instead of building one huge short life-span spacecraft, why not launch hundreds or thousands of lower cost, less capable birds incrementally? You can start with a small "first light" capable instrument with a dozen or so spacecraft, then over time and more launches put up more and more capability and decommission failed or low capability pieces.
Use some computational methods to combine the sensor collection from dozens, hundreds, or thousands of these kinds of spacecraft and you could end up with planet sized instruments pretty efficiently.
By eliminating lots of the hard engineering for the massive instruments (like serviceability, difficult to make massive mirrors, etc) you can build even better instruments that are generational and relatively inexpensive.
You get a more flexible funding story as well, e.g. fund at maintenance levels during difficult economic times and fund at larger amounts during boom times with matching launch schedules.
Tasking the fleet could be more dynamic as well, with different researchers able to reserve different percentages of a huge fleet for their specific experiments and needs -- e.g. reserve a hundred spacecraft for a long dwell "deep field" type observation, or reserve thousands for planetary imaging in a nearby solar system.
I know there are naysayers about this who think it's improbable. I urge those to think about the Starlink fleet, which went from zero birds in the air in 2015 to over 1500 spacecraft today. Now instead of radio antenna, what if they had imaging sensors and were turned to face out? SpaceX certainly didn't spend anywhere near what JWST ran as a program to reach this point and the development time has been a fraction so far.
Instead of building one huge short life-span spacecraft, why not launch hundreds or thousands of lower cost, less capable birds incrementally? You can start with a small "first light" capable instrument with a dozen or so spacecraft, then over time and more launches put up more and more capability and decommission failed or low capability pieces.
Use some computational methods to combine the sensor collection from dozens, hundreds, or thousands of these kinds of spacecraft and you could end up with planet sized instruments pretty efficiently.
By eliminating lots of the hard engineering for the massive instruments (like serviceability, difficult to make massive mirrors, etc) you can build even better instruments that are generational and relatively inexpensive.
You get a more flexible funding story as well, e.g. fund at maintenance levels during difficult economic times and fund at larger amounts during boom times with matching launch schedules.
Tasking the fleet could be more dynamic as well, with different researchers able to reserve different percentages of a huge fleet for their specific experiments and needs -- e.g. reserve a hundred spacecraft for a long dwell "deep field" type observation, or reserve thousands for planetary imaging in a nearby solar system.
I know there are naysayers about this who think it's improbable. I urge those to think about the Starlink fleet, which went from zero birds in the air in 2015 to over 1500 spacecraft today. Now instead of radio antenna, what if they had imaging sensors and were turned to face out? SpaceX certainly didn't spend anywhere near what JWST ran as a program to reach this point and the development time has been a fraction so far.
I doubt the large space telescope programs will end, there will just be other options to how they're done. Scientists will still push the state of the art (if they get the funding) which will still be expensive and might still involve big mirrors here and there for optical imaging. Building a large fleet radio telescope in space actually sounds like a good proposal for massive R&D space telescope program.
Unfortunately optical interferometry as suggested isn't a thing yet. Even the physical optical interferometry we do on the ground has only become possible relatively recently. I'm not in the field so I'm not sure what's around the corner but seems to rule out Hubble/JWST/WFIRST/LUVOIRE replacements any time soon. Maybe TESS like scanning imaging would be a good fit for a fleet?
The big change I hope will be easier, cheaper, regular access to space which hopefully means there won't be such unicorn projects that spend 4 years in systems testing because they _can't_ fail.
> Tasking the fleet could be more dynamic as well, with different researchers able to reserve different percentages of a huge fleet for their specific experiments and needs
Specific observations require specific instruments though, there's no one size fits all fit out for a fleet satellite. JWST has a very large mirror looking a near and mid infra red a long way from earth with large IR shielding. You can't do this and Kepler/Tess type imagery in a single fleet unless the sats are specifically equipped for it on the ground before launch and sent to vastly different places which kind of nullifies a really dynamic fleet.
Not saying that having a standardised, cheap satellite bus that can be quickly thrown up in space won't change things, it's just not the answer to everything.
Unfortunately optical interferometry as suggested isn't a thing yet. Even the physical optical interferometry we do on the ground has only become possible relatively recently. I'm not in the field so I'm not sure what's around the corner but seems to rule out Hubble/JWST/WFIRST/LUVOIRE replacements any time soon. Maybe TESS like scanning imaging would be a good fit for a fleet?
The big change I hope will be easier, cheaper, regular access to space which hopefully means there won't be such unicorn projects that spend 4 years in systems testing because they _can't_ fail.
> Tasking the fleet could be more dynamic as well, with different researchers able to reserve different percentages of a huge fleet for their specific experiments and needs
Specific observations require specific instruments though, there's no one size fits all fit out for a fleet satellite. JWST has a very large mirror looking a near and mid infra red a long way from earth with large IR shielding. You can't do this and Kepler/Tess type imagery in a single fleet unless the sats are specifically equipped for it on the ground before launch and sent to vastly different places which kind of nullifies a really dynamic fleet.
Not saying that having a standardised, cheap satellite bus that can be quickly thrown up in space won't change things, it's just not the answer to everything.
You need exceedingly accurate timing and transmission to do computational inference with multiple telescopes. Even minuscule errors will wreck the entire effort. It is very, very hard even with only three telescopes on earth, nevermind a hundred hurtling around in orbit communicating with lasers.
The people who work on these things aren’t morons, and everyone knows the scaling factor of multiple receivers. It’s just very, very hard.
The people who work on these things aren’t morons, and everyone knows the scaling factor of multiple receivers. It’s just very, very hard.
Sure it's hard, bit I'm not really even proposing anything new. Labeyrie has proposed such a fleet, but raw economics have put it off, not technology -- I'd hardly call him a slouch in astronomical interferometry.
> Instead of building one huge short life-span spacecraft
Short life-span? How long has the Hubble been up there?
Short life-span? How long has the Hubble been up there?
webb needs to use thrusters to stay in position. there’s 5 years worth of fuel onboard
they did design the fuel in a way that potentially could be refilled… but the refilling craft doesn’t exist. and webb timescales make that sound impossible
they did design the fuel in a way that potentially could be refilled… but the refilling craft doesn’t exist. and webb timescales make that sound impossible
According to the NASA website there is fuel for 10 years, and the five years is just the "minimal" mission time for which it's tested.
https://jwst.nasa.gov/content/about/faqs/faq.html#howlong
https://jwst.nasa.gov/content/about/faqs/faq.html#howlong
Question if anyone knows: ~9.5 years any reason to not push it out of orbit into space and continue to get signals back for years longer as it floats off? Like the voyagers?
To push it out in to space like Voyager requires a lot of thrust, so I bet that's the reason.
As far as I can find, it's kept in the L2 point mainly for temperature reasons.
Not an expert, but this is what I gathered from https://space.stackexchange.com/q/23238/13952 and https://space.stackexchange.com/q/38408/13952
From what I can tell I don't think that it's very uncommon that these things are designed for 5-10 year missions and that everything else is just a nice bonus. I don't think anyone expected Hubble to survive as long as it did for example, and even the Voyager program was originally designed to be finished in the 80s and I don't think anyone expected it would last this long either.
As far as I can find, it's kept in the L2 point mainly for temperature reasons.
Not an expert, but this is what I gathered from https://space.stackexchange.com/q/23238/13952 and https://space.stackexchange.com/q/38408/13952
From what I can tell I don't think that it's very uncommon that these things are designed for 5-10 year missions and that everything else is just a nice bonus. I don't think anyone expected Hubble to survive as long as it did for example, and even the Voyager program was originally designed to be finished in the 80s and I don't think anyone expected it would last this long either.
JWST isn't a probe like Voyager. It's job isn't to go to other worlds and see what's there. Its a space observatory. It does exactly the same job a telescope on earth would do, just in space. The reason why is to avoid light pollution and the interference from earth's atmosphere.
So that fuel isn't used for going places, its for aiming the telescope and keeping it steady. Once the fuel is gone it can no longer control where its pointing. If you cant aim a telescope then its useless.
So that fuel isn't used for going places, its for aiming the telescope and keeping it steady. Once the fuel is gone it can no longer control where its pointing. If you cant aim a telescope then its useless.
You can aim it with reaction gyros which rotate the telescope and require only electricity. What you cannot do with electricity is translate the telescope along a vector to compensate for orbital decay and keep it on station. That's what fuel is for.
I understand it's not designed for exploration, but my thinking is given the other alternative is burn it up in the atmosphere isn't it better to get a bit longer (few years?) use as it drifts off vs burnt up.
With the you need to aim it, could they sent it to a slow spin/wobble and time image capture as focus would occasionally pass by things of interest? Not sure if it needs to be relatively stable for that long timed exposure.
There is probably good reason for not doing this and trying to understand why.
With the you need to aim it, could they sent it to a slow spin/wobble and time image capture as focus would occasionally pass by things of interest? Not sure if it needs to be relatively stable for that long timed exposure.
There is probably good reason for not doing this and trying to understand why.
Don't worry, JWST isn't going to burn up for a few billion years. Until the Sun expands into a red giant at least.
They are sending it to the L2 lagrange point which is further out that the moon. That's also why they are so careful about making sure the origami sun shield works right the first time. If it screws up the whole mission is lost because there's no chance to fly some astronauts out there to fix it like we did with Hubble.
As for exposures while its spinning, I was under the impression these are really long exposures and require it to be precisely aimed for quite awhile.
They are sending it to the L2 lagrange point which is further out that the moon. That's also why they are so careful about making sure the origami sun shield works right the first time. If it screws up the whole mission is lost because there's no chance to fly some astronauts out there to fix it like we did with Hubble.
As for exposures while its spinning, I was under the impression these are really long exposures and require it to be precisely aimed for quite awhile.
> why they are so careful about making sure the origami sun shield works right
They cannot really test it on Earth, as it must work in free-fall. Given the past problems with unfolding these things, I have a horrible suspicion that it won't work, and we won't be able get to L2 to fix it.
They cannot really test it on Earth, as it must work in free-fall. Given the past problems with unfolding these things, I have a horrible suspicion that it won't work, and we won't be able get to L2 to fix it.
And it's at L2 so not that easy to get to
I take Starship could, and should be operational in some form by then.
Question is whether it'll be financially / commercially viable. I think that greatly depends on how much data the telescope gathers or whether it needs more time. Also keep in mind that the Hubble got multiple upgrades over its lifespan, which will be much more difficult with the Webb - is it feasible to do spacewalks that far out? Has any astronaut ever done a spacewalk outside of Earth orbit?
Are you referring to the protection by Earths magnetic field?
If so, would it matter much, given we (allegedly) shot humans in not more than slightly pressurized tin cans to the moon multiple times?
And they survived.
If so, would it matter much, given we (allegedly) shot humans in not more than slightly pressurized tin cans to the moon multiple times?
And they survived.
Yeah, if it has done it set out to do, then we don’t need to. Also depends how much of a moon presence we have in five years. Launching from the moon might make it feasible for sure, considering the billions the JWST has cost!
When you consider how long this thing was in development/production, 5 years doesn't seem very long.
It’s the telescope of Theseus, though.
Because some component bays designed to be swapped out were swapped out? Far as I know they haven’t replaced the 2.4m main mirror or the housing, you know, the “ship”
Yes, that is the joke I was making. Thank you for explaining it.
I think their point was your joke doesn't make much sense when only a small subsection of the entire telescope was ever replaced.
In my opinion that's part of what makes it funny, and is also a core issue in the Ship of Theseus problem -- who's to say how much it can be changed and is still "the same thing"? Maybe the thing that was replaced was very small but was very important to the identity.
That’s not what the Ship of Theseus is. The thought experiment is: if you replace 100% of the original object then is it the same object. Not like, if you change the batteries in the remote is it the same remote.
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Sort of. The broken optics famously got fixed in the first HST shuttle mission, and there have been other replacements over time. A lot of it is the same, though.
And of course, the HST is in LEO, which means it is reachable with current rocket tech, which the James Webb, being situated at L2 won't be. But that's not to say you could not have a large platform at L2 (or another Lagrange point) that could be serviced by robots, or even manned craft, if it was designed that way.
And of course, the HST is in LEO, which means it is reachable with current rocket tech, which the James Webb, being situated at L2 won't be. But that's not to say you could not have a large platform at L2 (or another Lagrange point) that could be serviced by robots, or even manned craft, if it was designed that way.
I guess my point was: without that servicing it would’ve been a pretty short life span (literally 0?). The swarm approach helps with this.
But Hubble wasn't a one-off design. It shared a lot of design elements with other space telescopes that are more earth-focused :) So it had a lot more benefits of scale than JWST.
> Use some computational methods to combine the sensor collection from dozens, hundreds, or thousands of these kinds of spacecraft and you could end up with planet sized instruments pretty efficiently.
This kind of thing cannot currently be done at optical wavelengths no matter how much computational power you throw at it; the frequencies are simply too high to do phase capture and syncing digitally.
It's done on a limited basis at the very large telescope (VLT) in Chile but the phase combiners there are optical and analog.
This kind of thing cannot currently be done at optical wavelengths no matter how much computational power you throw at it; the frequencies are simply too high to do phase capture and syncing digitally.
It's done on a limited basis at the very large telescope (VLT) in Chile but the phase combiners there are optical and analog.
Phone cameras show both the power and limits of computational photography. You can’t run away from physics forever.
Phone cameras don’t have multiple lenses working together that you can interpolate between to create a single giant virtual lens. The technique OP is referring to is already used for the largest ground based radio telescopes.
Well, a lot of phones do have multiple sensors and lenses. For example, the iPhone's computational depth effect uses multiple cameras for a single shot.
That’s qualitatively different from the kind of stitching together that happens with, e.g. the VLA. The computational limits of phone photography don’t apply here.
Exactly correct. And Labeyrie has a design in place for the exact type of fleet I'm talking about.
Do you have a link to the design? I'm assuming it's a radio telescope?
No the design is optical. Here's a white paper on the concept. https://www.google.com/url?sa=t&source=web&rct=j&url=https:/...
Labeyrie has also proposed a fleet in L2 and on the Moon.
Labeyrie has also proposed a fleet in L2 and on the Moon.
Not the OP, but I guess he is talking about the hypertelescope concept: https://hypertelescope.org/hypertelescope-en/
For additional background, there are already optical interferometry telescopes in use, see VLTI by the European Southern Observatory (Chile, shared facility with the four VLT telescopes and some smaller telescopes).
For additional background, there are already optical interferometry telescopes in use, see VLTI by the European Southern Observatory (Chile, shared facility with the four VLT telescopes and some smaller telescopes).
Deploying multiple smaller telescopes was one of the designs that was considered in the 90s for what eventually became the JWT.
I'm not an expert on any of this, and I don't know specifically why it was rejected, but it's not like people aren't thinking about all sorts of possibilities. Usually there's a reason they're not being done though.
I'm not an expert on any of this, and I don't know specifically why it was rejected, but it's not like people aren't thinking about all sorts of possibilities. Usually there's a reason they're not being done though.
Even if this computational photography vision is years away, JWST might still become obsolete quickly.
SpaceX's Starship would be able carry telescopes than JWST as a single piece. This would dramatically simplify development and increase optical quality.
SpaceX's Starship would be able carry telescopes than JWST as a single piece. This would dramatically simplify development and increase optical quality.
https://www.youtube.com/watch?v=kEECPKLHwl8
https://en.wikipedia.org/wiki/Large_strategic_science_missio...
They are already planning telescopes using Starship's capabilities, and one of these telescopes has a mirror that consists of several segments, albeit not hexagonal and is pre-assembled. The telescope is being touted as an overall cheaper solution due to the diameter that Starship could carry. But there is also a telescope that is an enlarged version of JSWT.
JWST is probably a required stepping stone for these future telescopes.
They are already planning telescopes using Starship's capabilities, and one of these telescopes has a mirror that consists of several segments, albeit not hexagonal and is pre-assembled. The telescope is being touted as an overall cheaper solution due to the diameter that Starship could carry. But there is also a telescope that is an enlarged version of JSWT.
JWST is probably a required stepping stone for these future telescopes.
The challenges in building a mirror that size is enormous and take years.
It is not only fairing size that is limiting
It is not only fairing size that is limiting
Wouldn't land-based telescopes already use larger mirrors than any space telescope?
Yes they do, but you have to consider the problems that the atmosphere poses. A lot of the budget for ground telescopes goes into the adaptive optics (actuators that can deform the mirror to compensate for distortions due to non-uniform column of air above the telescope). For adaptive optics to be effective you need bigger mirrors because you can't deform a small mirror enough to counter that.
Additionally, the atmosphere blocks a bunch of wavelengths that are really interesting to observe [1] so we still want to be in space for these observations.
Finally, in the non distant future I believe space telescopes will ditch mirrors altogether. For instance, the proposed Aragoscope [2] would use diffraction optics instead of so called geometric optics (lenses, mirrors) to focus light. Since the material that can provide the diffraction can be anything it would be much cheaper to launch a sheet of <insert light and bendy material here> that can unfold once in space instead of incredibly precise and fragile mirrors. Also, according to Nasa, this approach can achieve ~1000 time the resolution of HST at a fraction of the price and we are only limited by the size of the disk creating the diffraction.
[1] https://www.researchgate.net/figure/The-atmospheric-transmis... .
[2] https://www.nasa.gov/content/the-aragoscope-ultra-high-resol... .
Additionally, the atmosphere blocks a bunch of wavelengths that are really interesting to observe [1] so we still want to be in space for these observations.
Finally, in the non distant future I believe space telescopes will ditch mirrors altogether. For instance, the proposed Aragoscope [2] would use diffraction optics instead of so called geometric optics (lenses, mirrors) to focus light. Since the material that can provide the diffraction can be anything it would be much cheaper to launch a sheet of <insert light and bendy material here> that can unfold once in space instead of incredibly precise and fragile mirrors. Also, according to Nasa, this approach can achieve ~1000 time the resolution of HST at a fraction of the price and we are only limited by the size of the disk creating the diffraction.
[1] https://www.researchgate.net/figure/The-atmospheric-transmis... .
[2] https://www.nasa.gov/content/the-aragoscope-ultra-high-resol... .
Can you launch those mirrors into space on a rocket without them turning into very fine glass dust? Cuz I bet a lot of mirrors in land-based telescopes would simply shatter or break on a launch.
Haven't a clue. It's an interesting question. What kind of materials they're made out of (weight considerations?), what kind of forces they can take, what kind of support structures they require, etc.
why not build the mirror in space? I bet microgravity could help with some of the challenges of building one.
It is going to take long while to build infrastructure to support any kind of construction let alone high tech construction like this.
Also I don't know if there actual benefits in doing mirror construction in low gravity
Also I don't know if there actual benefits in doing mirror construction in low gravity
Could you back that up with anything? There is so much excitement about SpaceX, it seems like all I read about on HN.
Saul Perlmutter is a Nobel Prize winning astrophysicist and has been talking about doing this.
https://twitter.com/ChrisG_NSF/status/1412845923521204237?re...
https://twitter.com/ChrisG_NSF/status/1412845923521204237?re...
As already said, the problem is in coordination of multiple telescopes in spacetime.
It might be better to build one giant telescope piecemeal, by adding more and more small mirrors. A similar approach is taken by several terrestrial telescopes.
It would still be very interesting to have a few space telescopes distributed across the Solar system, much wider than the Earth orbit. It could give a sort of stereoscopic picture of closest star systems, even though "simultaneous" observation would be ill-defined for them.
It might be better to build one giant telescope piecemeal, by adding more and more small mirrors. A similar approach is taken by several terrestrial telescopes.
It would still be very interesting to have a few space telescopes distributed across the Solar system, much wider than the Earth orbit. It could give a sort of stereoscopic picture of closest star systems, even though "simultaneous" observation would be ill-defined for them.
Actually, pulsars can be used for timing and position, and all telescopes in your fleet could have sight of the same ones. It's probably far easier to do interferometry if you don't have atmospheric distortion to deal with.
Accordung to the theory of relativity, there's no such thing as "the same moment" between two distant bodies. When the distance is light milliseconds, we can pretend it does not exist. When it is light-seconds, like between Earth and GEO, it becomes hard to ignore. With many light hours which would separate the telescopes I was talking about, the idea of "the same moment" just becomes nonsensical, even in very approximate household terms.
Such telescopes could, of course, register the same compact body, like an exoplanet, and then their pictures could be put together on one timeline, the planet's, thus synchronized.
Maybe if a pulsar happens to be close (in angular terms) to the object observed, it could help synchronize the pictures. If the pulsar lies in a seriously different direction, it likely would be less helpful: most pulsars have rather short periods, and all pulses are the same.
Such telescopes could, of course, register the same compact body, like an exoplanet, and then their pictures could be put together on one timeline, the planet's, thus synchronized.
Maybe if a pulsar happens to be close (in angular terms) to the object observed, it could help synchronize the pictures. If the pulsar lies in a seriously different direction, it likely would be less helpful: most pulsars have rather short periods, and all pulses are the same.
OTOH it's much harder to do interferometry when you aren't able to sit on the ground and be stable: your refrigeration units can't be located somewhere far away to reduce vibration, and you can't stationkeep with nanometer accuracy (which may or may not matter depending on your frequency- in the past space based interferometry has usually only been practical for very long wavelengths)
The Starlink fleet has been a huge problem for the field of astronomy entirely do to this "move fast and break things" ethos.
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From watching the documentary linked in another comment, a big part of the JWST’s potential is its deep-infrared sensitivity, which in turn requires very cold temperatures and exquisite shielding, and why it will be literally 1 million miles from Earth. I don’t think you can fake that with computation.
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I'm building this! Minus the "computational methods" magic... Because as someone has already commented, there are significant issues with just merging the telescope data together with computational magic.
With the advent of SpaceX's Starship providing a 100% (and the 100% is crucial to the economics of this project) reusability there is significant potential to reduce many of the costs that normally increase the price of a satellite. From not throwing away a $10,000 PPOD (cubesat deployer) to the myriad cost savings available when you know the next flight is cheap and you don't need to buy a $500 part, where a $50 or even $5 part would do the job, due to the different risk profile in many smaller satellites, compared to a few larger ones.
> Instead of building one huge short life-span spacecraft, why not launch hundreds or thousands of lower cost, less capable birds incrementally? You can start with a small "first light" capable instrument with a dozen or so spacecraft, then over time and more launches put up more and more capability and decommission failed or low capability pieces.
Thats the basic plan in a nutshell. Start small, build up, from the ~10cm primary mirror "phase one" prototypes, to eventually using ~50cm primary mirrors. Steady progress using a standardised telescope "chassis" for each generation, with each having a specific camera/instrument rather than the common (for space telescopes) practice of having complicated multi-instrument optical pathways.
Think Planet Labs, but facing out at the universe, not down towards the ground, and a non-profit/charity not a commercial company.
I'll spare the whole spiel that I've regurgitated into grant proposals (space costs money and it would be nice if I didn't have to pay the entire $250,000 or more out of my own pay-check over the course of a decade) if you want to know more (or just talk about it, or offer to help, or whatever else at all) you can contact me directly (email in my HN profile) or wait till I publish the eventual website later this year, I'll be sure to post a Show HN once I have pretty pictures of hardware.
With the advent of SpaceX's Starship providing a 100% (and the 100% is crucial to the economics of this project) reusability there is significant potential to reduce many of the costs that normally increase the price of a satellite. From not throwing away a $10,000 PPOD (cubesat deployer) to the myriad cost savings available when you know the next flight is cheap and you don't need to buy a $500 part, where a $50 or even $5 part would do the job, due to the different risk profile in many smaller satellites, compared to a few larger ones.
> Instead of building one huge short life-span spacecraft, why not launch hundreds or thousands of lower cost, less capable birds incrementally? You can start with a small "first light" capable instrument with a dozen or so spacecraft, then over time and more launches put up more and more capability and decommission failed or low capability pieces.
Thats the basic plan in a nutshell. Start small, build up, from the ~10cm primary mirror "phase one" prototypes, to eventually using ~50cm primary mirrors. Steady progress using a standardised telescope "chassis" for each generation, with each having a specific camera/instrument rather than the common (for space telescopes) practice of having complicated multi-instrument optical pathways.
Think Planet Labs, but facing out at the universe, not down towards the ground, and a non-profit/charity not a commercial company.
I'll spare the whole spiel that I've regurgitated into grant proposals (space costs money and it would be nice if I didn't have to pay the entire $250,000 or more out of my own pay-check over the course of a decade) if you want to know more (or just talk about it, or offer to help, or whatever else at all) you can contact me directly (email in my HN profile) or wait till I publish the eventual website later this year, I'll be sure to post a Show HN once I have pretty pictures of hardware.
If the JWST survives launch but has a subsequent mechanical problem that prevents it deploying properly (and it’s the kind of problem that would have been fixable on Hubble, using a shuttle mission) would it be feasible to mount a robotic rescue mission to chase it down and remote-hands it back to life? For less than the cost of just launching another JWST?
The trouble with robotic repair missions is that it could work pretty well if you knew 100% exactly what was wrong, and exactly what else might go wrong while applying the fix for whatever went wrong. The more potential unknowns, the harder it is. It's much harder to make a robot with enough general flexibility that it could probably handle diagnosing and repairing an unknown issue, or handle something going wrong while trying to carry out a planned repair sequence. Bolts jammed, too loose, too tight, tanks of stuff springing leaks, electrical short in some unknown place, component overheating for unknown reason, all sorts of things can go wrong that are tough to diagnose remotely or with a special-purpose robot.
The JWST orbits out beyond the Moon, so I don't know if the Orion capsule and European Service Module even has the Delta-V to make it to that Lagrange point and back. Plus, I'm also unsure about the life support and duration requirements for such a mission.
I imagine the only realistic repair mission would be with a Starship crew, seeing as Orion and all the other Commercial Crew vehicles would probably require some additional components to make it out that far and to sustain their crews. Starship seems big enough and far enough along in development to be viable.
Edit: The JWST has a docking ring to let Orion service it. But I don't know if the SLS in it's available configurations can get it up there. It seems like a contingency but I don't see any solid information about an Orion service mission.
I imagine the only realistic repair mission would be with a Starship crew, seeing as Orion and all the other Commercial Crew vehicles would probably require some additional components to make it out that far and to sustain their crews. Starship seems big enough and far enough along in development to be viable.
Edit: The JWST has a docking ring to let Orion service it. But I don't know if the SLS in it's available configurations can get it up there. It seems like a contingency but I don't see any solid information about an Orion service mission.
The GP asked about robotic, not human missions.
My mind skipped over that. I don't have a good answer for a robotic mission but I imagine NASA won't fund it.
I would think that a cheaper (or multiple cheaper) versions could be made if they don't require the long lifespan and reliability that previous launch costs inflicted. Once Starship is going, and if it proves to be as low cost as the current projections, I could see multiple space telescopes being designed cheaply for a launch every year, each one designed in a narrow configuration that serves a specific purpose. But I really don't know what all goes into making a space telescope so expensive currently.
>> But I really don't know what all goes into making a space telescope so expensive currently.
I think you already said it. The long life (high reliability) requirement, and I'll add the complexity of having it unfold. Both of those become non-issues if you build the telescope right into a space-X starship. There may be other issues with that, but the mirror wouldn't need to fold ;-)
I think you already said it. The long life (high reliability) requirement, and I'll add the complexity of having it unfold. Both of those become non-issues if you build the telescope right into a space-X starship. There may be other issues with that, but the mirror wouldn't need to fold ;-)
Are you speaking to the reliability of the launch vehicle or of the satellite? The launch itself is typically not a primary cost driver of a satellite mission. Complexity may be, due to constraints of the fairings but the manufacturing and quality checks drive quite a bit of the cost
I think they mean reliability of the satellite. The JWST is going to be parked at a Lagrange point that's going to put it out of reach of most everything. At the time it was conceived, robotic servicing was even further off. A crewed mission was right out. Costs went far up in part because unlike Hubble, servicing was going to be virtually impossible.
Starship has a sufficient delta-v to service it.
Yes, but Starship is a prototype at the moment. And it'd require the Super Heavy to even reach orbit, which will soon begin testing [0].
Additionally, the engineering requirements for long-term life support are significantly more involved than the Dragon capsule.
There's also the testing and certification process for crewed-missions; in non-Elon time, this is likely several years, conservatively speaking [1]. (I'd love to be proven wrong, however!).
[0] https://www.space.com/spacex-starship-super-heavy-booster-ro...
[1] https://arstechnica.com/science/2021/04/five-reasons-why-nas...
Additionally, the engineering requirements for long-term life support are significantly more involved than the Dragon capsule.
There's also the testing and certification process for crewed-missions; in non-Elon time, this is likely several years, conservatively speaking [1]. (I'd love to be proven wrong, however!).
[0] https://www.space.com/spacex-starship-super-heavy-booster-ro...
[1] https://arstechnica.com/science/2021/04/five-reasons-why-nas...
It has a docking clamp, though that's for future-proofing. Apparently the initial type of mission envisioned was a crewed Orion vehicle, though I'm sure a wide variety of missions could attach.
My guess was that the clamp was mainly for possible future replenishment of consumables, though presumably some sort of robotic-arm-equipped repair mission could attach as well. A crewed mission seems possible, too, assuming one of the planned Lunar craft could be modified to go to the Lagrange point.
https://www.space.com/3833-nasa-adds-docking-capability-spac...
https://en.wikipedia.org/wiki/Spacecraft_Bus_(JWST)#Docking_...
My guess was that the clamp was mainly for possible future replenishment of consumables, though presumably some sort of robotic-arm-equipped repair mission could attach as well. A crewed mission seems possible, too, assuming one of the planned Lunar craft could be modified to go to the Lagrange point.
https://www.space.com/3833-nasa-adds-docking-capability-spac...
https://en.wikipedia.org/wiki/Spacecraft_Bus_(JWST)#Docking_...
Nothing in the current fleet of new capsules have arms or airlocks.
There is hope for the robotic refueling type mission though, or at least the kind where a new utility bot attaches to an old satellite and takes over propulsion to extend its life.
https://nexis.gsfc.nasa.gov/rrm_refueling_task.html
There is hope for the robotic refueling type mission though, or at least the kind where a new utility bot attaches to an old satellite and takes over propulsion to extend its life.
https://nexis.gsfc.nasa.gov/rrm_refueling_task.html
> Nothing in the current fleet of new capsules have arms or airlocks.
True, but a docking adapter with an airlock that works with starliner and dragon is technically feasible. That said, it would still likely require recertification, as its inclusion would effect abort modes.
True, but a docking adapter with an airlock that works with starliner and dragon is technically feasible. That said, it would still likely require recertification, as its inclusion would effect abort modes.
Highly unlikely. That would require designing a new spacecraft from the ground up while also developing new robotics and operations technologies. I'd peg that mission at $300 - $500 million. NASA would almost certainty be better off documenting lessons learned and pursuing a new observatory.
> I'd peg that mission at $300 - $500 million.
If that was the cost for that mission, it would be worth it considering JWST cost about 20x that amount.
If that was the cost for that mission, it would be worth it considering JWST cost about 20x that amount.
You are considering the entire cost of developing the JWST. Surely the cost of building another based on the finished design would be lower.
I think part of the reason the JWST took so long to build was the complexity of the design. As in, it was difficult to manufacture and assemble and test due to the way it was designed. It might be cheaper to do it a second time based on the lessons (avoiding mistakes) from the first, but it would probably still be quite expensive.
I wondered the same thing. I once read this commentary on project management (disguised as a StarWars fanfic)[1] which makes me pessimistic. However I'm in no way involved so I'd be curious to hear what someone more knowledgable thinks.
https://m.fanfiction.net/s/11685932/1/Instruments-of-Destruc...
https://m.fanfiction.net/s/11685932/1/Instruments-of-Destruc...
They've spent almost 10 billion dollars on this telescope so far. What's another 0.5 billion for a repair mission?
That 0.5 billion (which to be clear, is a number I made up) won't guarantee that JWST will be fixed. The "fixer" spacecraft could end up failing itself. Or it could discover new problems that it's not equipped to handle.
Also, congress would be extremely critical of NASA if JWST fails. They would not be excited to shell out another $0.5 billion for a chance to fix it.
Also, congress would be extremely critical of NASA if JWST fails. They would not be excited to shell out another $0.5 billion for a chance to fix it.
Not to mention that we don't even currently have a real capability to repair the currently malfunctioning Hubble telescope anymore. That was designed for maintenence from the now non-existent space shuttle in mind. Trying to accomplish the same with the Dragon would be unknown territory and it seems that there is little desire from both NASA and congress to even bother.
JWST in comparison is a far trickier and complicated beast to tinker with. This is the biggest reason why they are so paranoid about any fault before orbital launch. It would be all but impossible to service it - on both a technical and political level.
JWST in comparison is a far trickier and complicated beast to tinker with. This is the biggest reason why they are so paranoid about any fault before orbital launch. It would be all but impossible to service it - on both a technical and political level.
The JWST will not orbit Earth. It will be located near the second Lagrange point (L2) over 1,500,000 km away (The Moon is just 405,000 km from the Earth).
Space Shuttle could not have reached it.
Space Shuttle could not have reached it.
It's not an orbit, per se, but... it will go around the Earth once per year.
>> it will go around the Earth once per year.
I think more accurately it will go around the sun once per year. The earth will provide the extra gravitational pull (toward the sun) needed to orbit the sun at a larger radius than the earth in the same amount of time as the earth.
I think more accurately it will go around the sun once per year. The earth will provide the extra gravitational pull (toward the sun) needed to orbit the sun at a larger radius than the earth in the same amount of time as the earth.
It equally orbits the sun and the earth.
Normally, objects with smaller orbits take less time to make a circuit. But this is placed where the earth's gravity pulls it back, just enough to make it take one (earth) year to finish its smaller orbit. So gravity from the earth and the sun are involved.
Normally, objects with smaller orbits take less time to make a circuit. But this is placed where the earth's gravity pulls it back, just enough to make it take one (earth) year to finish its smaller orbit. So gravity from the earth and the sun are involved.
Only in the same sense as mars goes around the Earth. Meaningless concept. It never crosses inside Earth orbit.
Maybe "co-orbits the Sun with the Earth using Earth's gravity"
Maybe "co-orbits the Sun with the Earth using Earth's gravity"
How long can it stay stable at that point? Does it have thrusters to keep a station there? If so, how long is the fuel for them provisioned for?
Does use of the thrusters impact the sensors that the telescope uses?
Does use of the thrusters impact the sensors that the telescope uses?
The orbit needs to be actively maintained. The telescope was designed for a 5.5 year mission, but NASA says it could last up to 10.5 years with proper fuel management. It has two different types of thrusters under the "Propulsion Subsystem".
> One kind is called "Secondary Combustion Augmented Thrusters" (SCAT), and they are used for orbit correction (like applied changes in velocity for each maneuver the spacecraft makes and also for orbit station-keeping). The SCATs are bi-propellant thrusters, using hydrazine (N2H4) and dinitrogen tetroxide (N2O4) as fuel and oxidizer, respectively.
> The other kind of thruster on Webb is called a MRE-1, or mono-propellant rocket engine, since it only uses hydrazine. There are eight MRE-1s on Webb, and they are used for attitude control and momentum unloading of the reaction wheels
Ref: https://jwst-docs.stsci.edu/jwst-observatory-hardware/jwst-s...
> One kind is called "Secondary Combustion Augmented Thrusters" (SCAT), and they are used for orbit correction (like applied changes in velocity for each maneuver the spacecraft makes and also for orbit station-keeping). The SCATs are bi-propellant thrusters, using hydrazine (N2H4) and dinitrogen tetroxide (N2O4) as fuel and oxidizer, respectively.
> The other kind of thruster on Webb is called a MRE-1, or mono-propellant rocket engine, since it only uses hydrazine. There are eight MRE-1s on Webb, and they are used for attitude control and momentum unloading of the reaction wheels
Ref: https://jwst-docs.stsci.edu/jwst-observatory-hardware/jwst-s...
The L2 point is unstable with a period of 23 days? I believe, so the JWT needs a course correct burn to stay positioned correctly (called station keeping).
It does have thrusters - a ring of 16 hydrazine "burning" units that can produce thrust on 3 axis.
The fact that the L2 point is unstable and that thrusters are required puts a lifetime on the telescope - I think NASA plans for a minimum of 5 1/2 years and are hoping to get up to 10. That's entirely reliant on the fuel supply.
The use of thrusters does impact the sensors the telescope uses. NASA et al schedule usable telescope time around burns, and general attitude shifts/correction. The telescope uses a bunch of gyroscopes/flywheels to point itself in the proper direction, during maneuvers like that the sensors aren't operable.
It does have thrusters - a ring of 16 hydrazine "burning" units that can produce thrust on 3 axis.
The fact that the L2 point is unstable and that thrusters are required puts a lifetime on the telescope - I think NASA plans for a minimum of 5 1/2 years and are hoping to get up to 10. That's entirely reliant on the fuel supply.
The use of thrusters does impact the sensors the telescope uses. NASA et al schedule usable telescope time around burns, and general attitude shifts/correction. The telescope uses a bunch of gyroscopes/flywheels to point itself in the proper direction, during maneuvers like that the sensors aren't operable.
> The fact that the L2 point is unstable and that thrusters are required puts a lifetime on the telescope - I think NASA plans for a minimum of 5 1/2 years and are hoping to get up to 10. That's entirely reliant on the fuel supply.
So when the fuel is exhausted the orbit decays and the unshielded telescope disintegrates on re-entry into Earth's atmosphere?
So when the fuel is exhausted the orbit decays and the unshielded telescope disintegrates on re-entry into Earth's atmosphere?
> So when the fuel is exhausted the orbit decays and the unshielded telescope disintegrates on re-entry into Earth's atmosphere?
Or drifts off into its own orbit around the Sun, but essentially yes.
Or drifts off into its own orbit around the Sun, but essentially yes.
> Does use of the thrusters impact the sensors that the telescope uses?
The point of sitting in a lagrange point is that you can stay there without moving due to two gravitational forces. That's not perfectly accurate, but I don't think it needs constant thrust, just occasional taps.
The point of sitting in a lagrange point is that you can stay there without moving due to two gravitational forces. That's not perfectly accurate, but I don't think it needs constant thrust, just occasional taps.
[deleted]
Seems to me it would be easier to design a craft to dock with it and bring back to an easier for humans to reach location. Then push it back out to where it needs to go. I'm sure there's some delta-v math to determine the fuel requirements, and I'm guessing it would also make a huge difference on how fast you wanted it back.
Latency is a bitch. So remote hands from earth is most likely a no-go, for this reason alone.
And if you bring astronauts close, then I guess that some EVAs in existing suits starts looking appealing vs developing those remote hands.
And if you bring astronauts close, then I guess that some EVAs in existing suits starts looking appealing vs developing those remote hands.
They wouldn't operating it like they play computer games. Mars rover has a major latency too, they can simply instruct it with limits and work slightly slower.
Also, all robotic space repair satellites are very into military tech (even taking pictures of open space is very strictly controlled, because you may inadvertently take a picture of a military satellite). Not event talking about disabling err.. repairing, de-orbiting, spinning etc other satellites. That types of tech is opposed by military, that's actually one of the reason we don't clear dangerous space garbage (especially considering some of that garbage is actually working military satellites).
> taking pictures of open space is very strictly controlled, because you may inadvertently take a picture of a military satellite
Citation needed
Citation needed
I worked in a private space company, that I was told by SatOps folks. I remember they said only US citizens on US territory could process the photos.
It is conceivable that on-orbit repair missions like OSAM-1 could fix a mission with a mechanical failure, depending on the orbit that it reaches.
https://nexis.gsfc.nasa.gov/osam-1.html
https://nexis.gsfc.nasa.gov/osam-1.html
When I look at project management for the small projects (1-20 people) I am working on I always wonder how projects of such a complexity are managed. It must be freakishly difficult to coordinate all the pieces.
The people working on this will also have several stressful months ahead of them. From launch to full deployment so many things can go wrong and there is nothing that can be done when something fails.
The people working on this will also have several stressful months ahead of them. From launch to full deployment so many things can go wrong and there is nothing that can be done when something fails.
I wonder the same for large (especially international) companies, government bureaucracies or other organizations. With thousands of employees and branches in different locations, it must be impossible to get a full understanding of the state of the system.
This is what Systems Engineers do. There's no magic bullet, but the basic process is lots and lots of documents. Much of what NASA does is published openly so you can get a feel for what some of these document types are like. The wiki page gives a decent summary.
Building a model for the system is indeed a big part of the challenge. These days it's increasingly done as a fully detailed software simulation. The big CAD packages have specific functionality for this now. For example SpaceX runs on Siemens NX, and you can wade through their marketing speak to get some idea of how it works. CATIA is also popular with aerospace companies, and Autocad's products with architecture.
Building a model for the system is indeed a big part of the challenge. These days it's increasingly done as a fully detailed software simulation. The big CAD packages have specific functionality for this now. For example SpaceX runs on Siemens NX, and you can wade through their marketing speak to get some idea of how it works. CATIA is also popular with aerospace companies, and Autocad's products with architecture.
“ There's no magic bullet, but the basic process is lots and lots of documents.”
That’s probably it. My company has systems engineers and even in relatively small projects you often have inconsistent and incomplete requirements. It’s one thing to design a piece of hardware but you also need to track how logistics and other factors have an impact on the system. So you need a lot of people who constantly check these changes.
That’s probably it. My company has systems engineers and even in relatively small projects you often have inconsistent and incomplete requirements. It’s one thing to design a piece of hardware but you also need to track how logistics and other factors have an impact on the system. So you need a lot of people who constantly check these changes.
Ugh, I can't deal with Systems Engineering. It's a whole lot of gobbledygook before getting to the crux of the problem. A software engineering analogue would be FizzBuzz Enterprise Edition
https://github.com/EnterpriseQualityCoding/FizzBuzzEnterpris...
https://github.com/EnterpriseQualityCoding/FizzBuzzEnterpris...
I can understand not liking how bureaucratically onerous it is, but we don't really have a choice. It's imperfect but it's the only way we've found to manage highly complex large scale engineering projects. You certainly aren't going to build something like JWT with a just YOLO agile process unless you're literally willing to fail like 50 times before you get one right (aka the USSR approach to rockets).
The upside is automation is making it go smoother and be less burdensome, because simulated testing truly is high enough fidelity now it allows a bit more virtual trial and error in the process.
The upside is automation is making it go smoother and be less burdensome, because simulated testing truly is high enough fidelity now it allows a bit more virtual trial and error in the process.
>The upside is automation is making it go smoother and be less burdensome, because simulated testing truly is high enough fidelity
I agree to an extent, but there's also a risk of simulation breeding a false sense of security even when simulations are conducted well. The investigation of the CST-100 "anomalous" test flight had 21 findings related to software simulations and testing, some related to lack of fidelity. Not that fidelity wasn't possible, but it has some overtones of the Ariane 5 software issue in that there was a lack of integration testing within the different software components.
I agree to an extent, but there's also a risk of simulation breeding a false sense of security even when simulations are conducted well. The investigation of the CST-100 "anomalous" test flight had 21 findings related to software simulations and testing, some related to lack of fidelity. Not that fidelity wasn't possible, but it has some overtones of the Ariane 5 software issue in that there was a lack of integration testing within the different software components.
The good thing about simulations is that once you have figured out a problem it won’t make the same mistake again. That’s the strength of computing
I agree, but the problem with this case was that simulations led to complacency about not thinking they needed integration tests. That's much rarely in the hardware domain. It's not really meant to be a critique of simulations but rather how we use them.
I don’t like it either but in regulated industries like space, medical or aerospace it seems the only way to manage things in a controlled way.
Same, makes you wonder how much slack/tolerance is built into these systems and organizations, and whether that comes in the form of manpower, process, etc. and whether or not it’s planned for, or just naturally evolves in large enough instances.
Systems Engineering
I followed their account, the last few years have been test after test after test.
Here's the official release from the launch partner [0](Arianeespace and the Eeuropean Space Agency are providing the launch on an Ariane V rocket).
They are the ones responsible for that milestone of the project (NASA and JPL already completed manufacturing of the spacecraft).
Exciting news!
https://www.esa.int/Science_Exploration/Space_Science/Webb/W...
They are the ones responsible for that milestone of the project (NASA and JPL already completed manufacturing of the spacecraft).
Exciting news!
https://www.esa.int/Science_Exploration/Space_Science/Webb/W...
I really hope this isn't a "MAKE IT PASS, OR ELSE" situation.
this telescope doesn't deserve any functionality setbacks in exchange for more schedule setbacks.
a telescope made late because of fixes is a fully working telescope. a prematurely launched telescope is broken for its entire service life.
this telescope doesn't deserve any functionality setbacks in exchange for more schedule setbacks.
a telescope made late because of fixes is a fully working telescope. a prematurely launched telescope is broken for its entire service life.
I fully agree, my first gut reaction every time I read an update about the JWST is fear that something will go wrong. I hope they take all the time needed to get it right.
I do also wonder if interactions with air / moisture / dust will degrade the components faster than they would wear out in space, the longer it's here on Earth? I'm guessing this is all accounted for too, just crazy to think of all the variables at play in the success of a project like this.
I do also wonder if interactions with air / moisture / dust will degrade the components faster than they would wear out in space, the longer it's here on Earth? I'm guessing this is all accounted for too, just crazy to think of all the variables at play in the success of a project like this.
No, they know what's at stake. That's why it's been delayed... and delayed... and delayed...
The question we're all biting our nails for is - Will it work?
The question we're all biting our nails for is - Will it work?
The Hubble was launched broken. The mirror had a precision defect and produced blurry photos. A team had to go up and manually correct the focus.
https://www.nasa.gov/content/hubbles-mirror-flaw
https://www.nasa.gov/content/hubbles-mirror-flaw
A post launch fix of this type will not be possible for JWST due to the solar (not Earth) orbit of the instrument.
Can’t do that with this orbit
What is it hoped this can see? Is there some specific hypothesis this telescope was built to confirm?
The oldest galaxies that have red shifted off the spectrum and are only visible with this. You can’t do IR telescoping except at L2 because earth is giving off its own IR reflection or radiation or something like that
Hopefully it'll tell us about the period of reionisation, when the light of the first galaxies made the universe transparent again.
It should be able to detect the atmospheric makeup of expo planets (via spectroscopy during a transition). This will let scientists search for signs of life on other planets.
I remember getting excited about this telescope a decade ago. I haven't heard of it since; but I thought it's budget was cut and it was over.
I'm excited NASA is finally going to get it up in space!
I'm excited NASA is finally going to get it up in space!
Actually the budget was overrun quite a bit. I think it will cost $10B at this point.
$9.5 billion over is pocket change! If you adjust for inflation $10 billion is only $7.7 billion in 2007 dollars. Assuming the telescope works I can live with it being expensive.
Unlike the F-35, I think the taxpayers are getting their money's worth.
Unfortunately, I think it's easier to fund something like the F-35 because it can be framed as a way to avoid an existential threat. It's difficult to do the same with fundamental science
The F-35 was framed as a way to save money.
That argument only holds because it was purported to replace different weapons systems that were needed for mitigating a threat. The threat is the primary motivation and cost reduction is secondary. I.e., if not but for the existential threat there's no need for the JSF or any system it would replace.
The F-22 was sufficient for threat mitigation. The F-35 raison d'être was cost reduction, after that was exportability which again was supposed to help with cost reduction.
Edit; comparing the logic of a 'but for' vs a 'necessary' condition. Was the F-35 necessary for threat mitigation. No. Was it framed as the necessary for cost savings, yes.
Edit; comparing the logic of a 'but for' vs a 'necessary' condition. Was the F-35 necessary for threat mitigation. No. Was it framed as the necessary for cost savings, yes.
Their designed for slightly different roles. The F-35’s R&D looks hard to justify vs simply having more F-22, but the F-35B can do verticals takeoff for example and the F-22 can’t.
So, the real question is if the F-35’s should have had fewer versions and thus been more capable in it’s remaining roles.
So, the real question is if the F-35’s should have had fewer versions and thus been more capable in it’s remaining roles.
There's similar analogies here to the space shuttle.
For the shuttle to get approved, it had to meet the demands of many masters. The fact that it had to meet DoD missions as well as NASA missions made it a bit of a boondoggle. Likewise, the JSF needed to meet the Marine Corps demands of VTOL to take the place of the AV8B.
It's hard to remain focused when you have so many stakeholders. As the saying goes, a camel is a horse designed by committee.
For the shuttle to get approved, it had to meet the demands of many masters. The fact that it had to meet DoD missions as well as NASA missions made it a bit of a boondoggle. Likewise, the JSF needed to meet the Marine Corps demands of VTOL to take the place of the AV8B.
It's hard to remain focused when you have so many stakeholders. As the saying goes, a camel is a horse designed by committee.
The space shuttle wasn't as bad as its reputation though. Both accidents had organizational causes and were entirely avoidable. And its huge payload bay and the fact it was a mobile base allowed for the construction of the ISS.
It just failed at reusability, it was more like refurbishability :) But many lessons have been learned from that.
It just failed at reusability, it was more like refurbishability :) But many lessons have been learned from that.
I'm speaking more to the shuttle cost overruns, both in design and mission. I'd argue that the reusability aspect was central to the idea of a "shuttle" and if it failed at that, it missed its mark.
I agree 100% that there are organizational causes to past mishaps. As to whether or not it was avoidable...I tend to think they are rooted very much in human psychology and we think about risk. The same issues occur today within NASA (EVA 23 is a good example [1], despite the 'organizational' fixes put in place after Challenger and Columbia). Humans are really, really good at rationalizing the answer we emotionally want.
[1] https://www.nasa.gov/sites/default/files/files/Hansen_PressC...
I agree 100% that there are organizational causes to past mishaps. As to whether or not it was avoidable...I tend to think they are rooted very much in human psychology and we think about risk. The same issues occur today within NASA (EVA 23 is a good example [1], despite the 'organizational' fixes put in place after Challenger and Columbia). Humans are really, really good at rationalizing the answer we emotionally want.
[1] https://www.nasa.gov/sites/default/files/files/Hansen_PressC...
F-22 theoretically can do a vertical take off as well. (not landing).
It has a thrust-to-weight ratio > 1, but it can't really take off vertically in the same sense as the AV8B or the JSF. The F22 still needs some appreciable runway so it's really a "short takeoff". I think the thrust vectoring maxes out around 25 degrees, where the JSF can be configured to 90 degrees.
>Was the F-35 necessary for threat mitigation. No. Was it framed as the necessary for cost savings, yes.
I think we're saying the same thing. The argument is, "Was the F22/F18/Fwhatever/weapon-system necessary for threat mitigation? Yes."
With that said, if proponents of the F35 want to frame it as "threat reduction + cost savings" that's how they get the budget approved. But the point stands that without a threat, there's no basis for the cost savings argument. I'm not saying it was effective as cost reduction.
To circle back to the original point, it's much easier to get a budget approved when the basis is existential threat, rather than "science is cool."
I think we're saying the same thing. The argument is, "Was the F22/F18/Fwhatever/weapon-system necessary for threat mitigation? Yes."
With that said, if proponents of the F35 want to frame it as "threat reduction + cost savings" that's how they get the budget approved. But the point stands that without a threat, there's no basis for the cost savings argument. I'm not saying it was effective as cost reduction.
To circle back to the original point, it's much easier to get a budget approved when the basis is existential threat, rather than "science is cool."
I don’t think it’s a great example of using existential threat for sales, when the whole thing was sold as a cost saving. Pretty much everyone at the time just wanted more F-22s. I was a technical advisor on the project.
>I don’t think it’s a great example of using existential threat for sales, when the whole thing was sold as a cost saving.
Again, if there is no threat (perceived or real), there is no need for a weapons system, period. Think of it this way, if there was a proposal for a cost savings for an anti-spacecraft/anti-asteroid system mounted to the JWST? I'm saying no, because there is no credible threat that would prevent. You need the threat first, in order for the cost savings of a program to have meaning if the basis of the program is threat mitigation.
>Pretty much everyone at the time just wanted more F-22s
Not really, unless you're only talking about a specific branch. Only the Air Force wanted F22s. As was stated by another commenter, the JSF was needed because it was because it fulfilled desires that other services had that the F22 does not provide.
Again, if there is no threat (perceived or real), there is no need for a weapons system, period. Think of it this way, if there was a proposal for a cost savings for an anti-spacecraft/anti-asteroid system mounted to the JWST? I'm saying no, because there is no credible threat that would prevent. You need the threat first, in order for the cost savings of a program to have meaning if the basis of the program is threat mitigation.
>Pretty much everyone at the time just wanted more F-22s
Not really, unless you're only talking about a specific branch. Only the Air Force wanted F22s. As was stated by another commenter, the JSF was needed because it was because it fulfilled desires that other services had that the F22 does not provide.
Threat mitigation is largely nuclear shield; but if you’re taking about maintaining air superiority then the F-22 is where it is at. The Navy carrier fleets and Marines are force projection.
The JSF were sold around cost savings; half the price so you could buy twice as many.
The JSF were sold around cost savings; half the price so you could buy twice as many.
> Pretty much everyone at the time just wanted more F-22s
The Navy and Marine Corps didn't, especially after development of the Naval variant of the F-22 was cancelled in 1991.
The Navy and Marine Corps didn't, especially after development of the Naval variant of the F-22 was cancelled in 1991.
I’m sure the Navy wished it wasn’t canceled, and the Marines probably would have been happy with Harriers.
The stealth window of usefulness is closing anyway with improved radar.
The stealth window of usefulness is closing anyway with improved radar.
Your oversimplifying and missing a lot. The F-35 is not a replacement or substitute for the F-22.
The F-22 is an air superiority fighter. The F-35 is a multi role strike aircraft. The F-22 would never be allowed for export, because it has features we don't want to share even with allies. The F-35 was designed for export to allies from day one.
There's no scenario where just buying more F-22's made more sense than building the F-35. The F-35's project problems, primarily driven from the joint acquisition strategy are their own thing, completely independent of the F-22.
The F-22 is an air superiority fighter. The F-35 is a multi role strike aircraft. The F-22 would never be allowed for export, because it has features we don't want to share even with allies. The F-35 was designed for export to allies from day one.
There's no scenario where just buying more F-22's made more sense than building the F-35. The F-35's project problems, primarily driven from the joint acquisition strategy are their own thing, completely independent of the F-22.
The F-35's problems as I understand it stem principally from the Navy wanting a VTOL craft. That whole system seems to be front and center when "stuff not working" comes up.
Marines not Navy, though they're a sub org of the Navy so a reasonable thing to say.
There's a Rand study on it. They concluded that the attempts at commonality didn't just fail, they proved counterproductive. They did a historical review of joint acquisition programs and found basically all of them hit the same flaw. As appealing as it may seem to congress, it's a bad strategy.
The F-35's problems as far as budget and schedule slippage were largely in the software section, and a lot of that goes back to structuring it as a single source cost plus contract. That incentivized LM to make the project as big and delayed as possible.
LM is infamous for this sort of thing. They turned Aegis into a clown circus of a billion different ship specific variants where they could charge N times to fix the same flaw in different nearly identical codebases. The Navy has been trying to extract themselves from it for like 2 decades now, with some signs of success finally showing up.
In short, LM is behaving in bad faith. This is unsurprising. They basically invented these tactics some decades back.
Back when Ash Carter was Sec Def, he called in LM and demanded they start hitting the promised numbers on marginal airframe costs. Reportedly the conversation went something like "do this or we'll curtail our buy" to which LM responded "by how much?" As replied "how about none?"
Suddenly they started hitting the numbers, surprise surprise.
We're about to have the same conversation about sustainment costs. I hope Austin drives as hard a bargain.
If you've read any of the limited info coming out about some of the AF's new projects like the B-21 or NGAD, it's pretty clear they took the lessons from the F-35 to heart and are using a very different approach, one where they hold the reigns of integration and can create competition at any time.
There's a Rand study on it. They concluded that the attempts at commonality didn't just fail, they proved counterproductive. They did a historical review of joint acquisition programs and found basically all of them hit the same flaw. As appealing as it may seem to congress, it's a bad strategy.
The F-35's problems as far as budget and schedule slippage were largely in the software section, and a lot of that goes back to structuring it as a single source cost plus contract. That incentivized LM to make the project as big and delayed as possible.
LM is infamous for this sort of thing. They turned Aegis into a clown circus of a billion different ship specific variants where they could charge N times to fix the same flaw in different nearly identical codebases. The Navy has been trying to extract themselves from it for like 2 decades now, with some signs of success finally showing up.
In short, LM is behaving in bad faith. This is unsurprising. They basically invented these tactics some decades back.
Back when Ash Carter was Sec Def, he called in LM and demanded they start hitting the promised numbers on marginal airframe costs. Reportedly the conversation went something like "do this or we'll curtail our buy" to which LM responded "by how much?" As replied "how about none?"
Suddenly they started hitting the numbers, surprise surprise.
We're about to have the same conversation about sustainment costs. I hope Austin drives as hard a bargain.
If you've read any of the limited info coming out about some of the AF's new projects like the B-21 or NGAD, it's pretty clear they took the lessons from the F-35 to heart and are using a very different approach, one where they hold the reigns of integration and can create competition at any time.
So was STS (Space Shuttle). . .
All those European tax payers are certainly getting their money's worth
Yes, if you prefer eye candy photos to public safety. By the way will James Webb wield a modern eye candy capable sensor? Not sure about that.
There is few worth from remote sensing unreachable (even in theory) objects. Kepler already proved theoretized Goldilocks Zone rocky planets and, in general, provided a lot of data for non-field research (less exciting than Hubble photos indeed). Last, but not least, what's the JWST's mission exactly?
Also, from taxpayers' money perspective Kepler's component quality was complete disaster.
So, I'd better invest in more Martian/Jovian probes than in revival of obsoleted project. Such revival is very similar to Russian GLONASS (a competitor to 1970s NAVSTAR) programme reboot.
There is few worth from remote sensing unreachable (even in theory) objects. Kepler already proved theoretized Goldilocks Zone rocky planets and, in general, provided a lot of data for non-field research (less exciting than Hubble photos indeed). Last, but not least, what's the JWST's mission exactly?
Also, from taxpayers' money perspective Kepler's component quality was complete disaster.
So, I'd better invest in more Martian/Jovian probes than in revival of obsoleted project. Such revival is very similar to Russian GLONASS (a competitor to 1970s NAVSTAR) programme reboot.
The JWST's mission is to see deep infared, which can pass through interstellar clouds. It will uncover things that have been veiled to us since the beginning of history. It can only be built as a space telescope because the frequency of its intended observations are so low that to a device sensitive to them, air radiates light of blinding intensity.
Thanks for this comment; that's a fascinating bit of information.
But that was just like saying what F-35's mission is to fly high in the skies, sorry.
This sort of proves my point, no one knows which exactly research JWST will do upon deployment, because original mission goals mainly became obsolete.
This sort of proves my point, no one knows which exactly research JWST will do upon deployment, because original mission goals mainly became obsolete.
There is a long list of scientists that know exactly what research they are doing on JWST down to the minute [0]
For example, Dr Christine Chen et al will be using JWST for at least 34.9 hours to study the Icy Kuiper Belts in Exoplanetary Systems using near infrared spectroscopy [1]
[0] https://www.stsci.edu/jwst/science-execution/approved-progra...
[1] https://www.stsci.edu/jwst/phase2-public/1563.pdf
For example, Dr Christine Chen et al will be using JWST for at least 34.9 hours to study the Icy Kuiper Belts in Exoplanetary Systems using near infrared spectroscopy [1]
[0] https://www.stsci.edu/jwst/science-execution/approved-progra...
[1] https://www.stsci.edu/jwst/phase2-public/1563.pdf
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>This sort of proves my point, no one knows which exactly research JWST will do upon deployment
The research isn't a secret, JWST is already booked solid for like 18 months after it launches. You can see how that time is allocated across various projects here: https://www.stsci.edu/jwst/science-execution/approved-progra...
The research isn't a secret, JWST is already booked solid for like 18 months after it launches. You can see how that time is allocated across various projects here: https://www.stsci.edu/jwst/science-execution/approved-progra...
Yeah, I read that, just not impressed by minor projects with low outcome. It roughly equal to routine PhD-tier experiments done on the accelerator at some provincial lab.
Just look at breakthrough chances from, for example, 5 days trans-neptunian object search or the pointing of instrument at largely unexplored Uranus system for petty 30 hours.
Just look at breakthrough chances from, for example, 5 days trans-neptunian object search or the pointing of instrument at largely unexplored Uranus system for petty 30 hours.
I hate how shortsighted these comments tend to be, but I can understand them.
The money for projects like this, largely due to the sensitive nature of it all, still ends up staying local to the governments funding the projects, which means a significant minority of it still gets recouped in taxes two or three degrees down, and the balance that can't be recouped still ends up funding colossal technological advances, e.g advances in EM sensors, lensing, computing, electronic resiliency, power generation, the list goes on.
The reason governments spend on projects like this regardless of public opinion is because they're necessary to advance the state of science and engineeeing when investment returns are out of the question near-term.
Even defense spending operates this way, though the degree to which we pour good money after bad in defense is probably worth scrutiny. At least JWST will bring value, unlike the f35.
The money for projects like this, largely due to the sensitive nature of it all, still ends up staying local to the governments funding the projects, which means a significant minority of it still gets recouped in taxes two or three degrees down, and the balance that can't be recouped still ends up funding colossal technological advances, e.g advances in EM sensors, lensing, computing, electronic resiliency, power generation, the list goes on.
The reason governments spend on projects like this regardless of public opinion is because they're necessary to advance the state of science and engineeeing when investment returns are out of the question near-term.
Even defense spending operates this way, though the degree to which we pour good money after bad in defense is probably worth scrutiny. At least JWST will bring value, unlike the f35.
Well, all the tech advances brought by doing R&D of JWST happened already ~15 years ago and already are at the market. But its just the same thing as with R&D done for F-35. With notable exception F-35's R&D is still work in progress because of upgrades, while JWST will remain a piece of late 2000s tech to be taken out of the attic in early 2020.
Another important point to consider is that by having these big projects you maintain the ability to do them, capabilities need to be maintained by exercising them.
It's roughly the same costs as Hubble ($9.3 billion in 2020 USD), and that excludes the costs for the mirror correction they had to do.
It seems clear the original estimate of $500 million was overly optimistic; actually, it was criticized almost immediately as such after publication. There's a lot of incentive to low-ball these initial cost estimates.
It seems clear the original estimate of $500 million was overly optimistic; actually, it was criticized almost immediately as such after publication. There's a lot of incentive to low-ball these initial cost estimates.
It's ESA that's getting it up into space, NASA is "just" collaborating.
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I bet it will fail to deploy properly. But I hope not.
This is one of the most daring missions. In case of any malfunction there will be no chance of reparing. Everything has to go right
It's pretty close to launch, but it still feels like it's not going to be ready for a few more years!
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Time-lapse video of it opening (~1:20):
https://www.bbc.com/news/science-environment-57078657
https://www.bbc.com/news/science-environment-57078657
I feel like this is an all-eggs-in-one-basket mission. If it fails to launch, we have nothing.
Why not build many JWSTs, surely the cost per unit would go down, and launch more than one?
Why not build many JWSTs, surely the cost per unit would go down, and launch more than one?
> surely the cost per unit would go down, and launch more than one?
Surely? They didn't build a JWST factory. It might go up, as people with specialized skills or knowledge have moved on.
Surely? They didn't build a JWST factory. It might go up, as people with specialized skills or knowledge have moved on.
Yes, surely. Most of the cost was in R&D and in the mirror manufacturing. They've been designing and manufacturing it for 20 years. Per-unit costs would go down. Take the mirror, it's made of segments, the facility used to produce those segments certainly would benefit from scaling up production. They'd get better at fabbing them over time, increasing yields, reducing costs.
What NASA is doing is building the equivalent of a $10 billion fab to produce one chip. Space telescopes could be continually produced on a schedule, and retired on a schedule, with constant improvement.
Look at RS-25 engines vs Raptor engines in terms of costs to produce one.
What NASA is doing is building the equivalent of a $10 billion fab to produce one chip. Space telescopes could be continually produced on a schedule, and retired on a schedule, with constant improvement.
Look at RS-25 engines vs Raptor engines in terms of costs to produce one.
Increasing production from 1 unit to 2 doesn't necessarily reduce costs. Due to demand and limited supply, for example, some prices increase. We know almost nothing about this thing. It's very speculative to say the cost would decrease. Also, how many space telescopes of this variety do we need?
All that said, it would be interesting to see NASA research on mass producing the more common components of its 'product line'. It does it for rockets, of course, but computers? Solar panels? Mars rover components? I'm sure it's been considered and I expect it's done in ways I'm not aware of.
All that said, it would be interesting to see NASA research on mass producing the more common components of its 'product line'. It does it for rockets, of course, but computers? Solar panels? Mars rover components? I'm sure it's been considered and I expect it's done in ways I'm not aware of.
Certainly a lot of the cost of the project is R&D, but most people would be shocked by how much of aerospace project budgets are driven by quality. E.g., a bolt costs $200 not because it has to go through a new R&D cycle, but because it needs a chain-of-custody, inspections, metal coupons stored, etc.
There's also a huge amount of political risk for a government entity. Politicians will be reluctant to fund another JWST if the first one fails because many will fight it as a waste of money, and the previous failure just bolsters the JWST-opponent's position.
There's also a huge amount of political risk for a government entity. Politicians will be reluctant to fund another JWST if the first one fails because many will fight it as a waste of money, and the previous failure just bolsters the JWST-opponent's position.
I think the verb tenses were not perfect... I think he just meant: why did they build only 1 in the first place? They could have built N instead, at a lower cost per unit.
Because there's only one L2 point, and it'd be very risky to have two units orbiting. So your spare would just sit around costing money in the case the first one works. The folks that do this are pretty dang good at what they do, so they're willing to bet $10 billion on success the first time, vs $20 billion to hedge with a spare. Even with a spare it's not clear to me a malfunctioning first example would have enough Delta-V to get it safely out of the L2 point proximate.
If it fails, they'll learn all they can, then try again with another follow on project, that likely will take advantage of technological improvements since functional requirements on this one were set in stone. Pre-building a spare just doesn't make sense with this kind of project.
If it fails, they'll learn all they can, then try again with another follow on project, that likely will take advantage of technological improvements since functional requirements on this one were set in stone. Pre-building a spare just doesn't make sense with this kind of project.
Space/Science/Military spending do not seem to follow the normal rules of civilian production nor schedules. Alos, once the satellite is built and launched, there is the ongoing budgeting of the actual operations of the satellite. The budgets are limited in those capacities as well.
The cost per unit would probably remain around the same. You don’t really get price cuts for ordering 2 of a custom component instead of 1
While it‘s awesome to finally see the JWST finally come to close to launch after all those years, now it‘s a close race between it and SpaceX Starship that could have taken the 6.5 meter mirror up to space in one whole piece in its 9m diameter belly rather than having to do all the miraculous origami that took two decades to develop in the first place…
While I'm rooting for SpaceX with Starship, lets be clear: they're still trying to get hovering grain silo versions working. Meanwhile JWT is ready to go. If it's a race one side has already won rather emphatically.
Actually, they're well beyond the "grain silos" by now. They've successfully demonstrated the "bellyflop" landing maneuver from a terminal velocity fall, and now they're (credibly) trying to launch a full prototype Starship stack to orbit within the next few months.
Wiki says JWST is planned to launch by this November, so I think there is a decent chance Starship beats it into space. That won't be a production-ready vehicle, and launching anything valuable on it (let alone something like the JWST) would be certifiable, but let's give credit where it's due.
Wiki says JWST is planned to launch by this November, so I think there is a decent chance Starship beats it into space. That won't be a production-ready vehicle, and launching anything valuable on it (let alone something like the JWST) would be certifiable, but let's give credit where it's due.
I know where SpaceX is. Elon does have a clear history of being overly optimistic about timelines.
There's a zero percent chance they'll have a vehicle ready by the JWT launch date that could launch it instead, even if they get to orbit by then.
This is not a race. As I said I'm a SpaceX fan, but I am not a fan of every single space topic being derailed by "but what about SpaceX?" as if they're the only company doing things meaningful in the industry. They're the super cool new kid on the block, but there's still a lot more out there that doesn't deserve to constantly be lampooned for not being SpaceX.
There's a zero percent chance they'll have a vehicle ready by the JWT launch date that could launch it instead, even if they get to orbit by then.
This is not a race. As I said I'm a SpaceX fan, but I am not a fan of every single space topic being derailed by "but what about SpaceX?" as if they're the only company doing things meaningful in the industry. They're the super cool new kid on the block, but there's still a lot more out there that doesn't deserve to constantly be lampooned for not being SpaceX.
> I know where SpaceX is.
I mean, Musk may be famous for his "optimistic" timelines, but you completely misrepresented their progress. "Still trying to get hovering grain silo versions working" is not remotely accurate.
That's the only point of my previous comment: give credit where it's due, as I said. I agree with most or all of the other things you've said in this subthread.
I mean, Musk may be famous for his "optimistic" timelines, but you completely misrepresented their progress. "Still trying to get hovering grain silo versions working" is not remotely accurate.
That's the only point of my previous comment: give credit where it's due, as I said. I agree with most or all of the other things you've said in this subthread.
I am giving credit. I'll call it working when they've demonstrated repeated access to orbit. Until they, they are indeed playing with flying grain silo prototypes, even if they landed one belly flop maneuver.
In any case, this is the exact sort of argument I find entirely wasteful of energy, and a distraction from what we should be talking about in this thread, which is JWT.
In any case, this is the exact sort of argument I find entirely wasteful of energy, and a distraction from what we should be talking about in this thread, which is JWT.
> I am giving credit.
No, you aren't. "Still trying to get hovering grain silo versions working" is not an accurate characterization of the current state of Starship development: they had hovering in the bag months ago, and have since demonstrated much more challenging and impressive capabilities.
> I'll call it working when they've demonstrated repeated access to orbit. Until they, they are indeed playing with flying grain silo prototypes, even if they landed one belly flop maneuver.
None of this is germane to the problems with your original statement. It's just empty snark--if you want to call rockets "grain silos", I'm not going to try to stop you, though I might caution you against erasing your ability to identify actual silos full of grain.
> In any case, this is the exact sort of argument I find entirely wasteful of energy, and a distraction from what we should be talking about in this thread, which is JWT.
I'm just here to correct the record, which I think is reasonable as there's a lot of weird SpaceX misinformation out there, both "for" and "against". Personally I don't understand why people can't just sit back and watch what happens, without putting their own spin on it.
No, you aren't. "Still trying to get hovering grain silo versions working" is not an accurate characterization of the current state of Starship development: they had hovering in the bag months ago, and have since demonstrated much more challenging and impressive capabilities.
> I'll call it working when they've demonstrated repeated access to orbit. Until they, they are indeed playing with flying grain silo prototypes, even if they landed one belly flop maneuver.
None of this is germane to the problems with your original statement. It's just empty snark--if you want to call rockets "grain silos", I'm not going to try to stop you, though I might caution you against erasing your ability to identify actual silos full of grain.
> In any case, this is the exact sort of argument I find entirely wasteful of energy, and a distraction from what we should be talking about in this thread, which is JWT.
I'm just here to correct the record, which I think is reasonable as there's a lot of weird SpaceX misinformation out there, both "for" and "against". Personally I don't understand why people can't just sit back and watch what happens, without putting their own spin on it.
> if you want to call rockets "grain silos", I'm not going to try to stop you, though I might caution you against erasing your ability to identify actual silos full of grain.
Agreed, they're definitely flying water tanks :)
Agreed, they're definitely flying water tanks :)
SpaceX has nothing to do with this. Their rocket has zero demonstrated capability for this mission.
I wouldn't trust any payload on a SpaceX ship given their track record.
The Falcon 9 has had 126 missions so far and only 2 of those were failures. It's not a perfect record, but it's pretty decent. And presumably SpaceX has learned from those failures. Compare that to the Ariane 5 rockets (which will actually be launching the James Web Space Telescope) which has had 109 launches, and 5 of them ended in failure.
I'm just going to assume you're referring to Starship's various explosions. It's far too early in the Starship development cycle to draw any kind of conclusions about it's reliability.
Starship is a prototype. It's a completely new vehicle with completely new engines, and they're building it with the expectation that the early versions are going to blow up. It's like saying Falcon 9 is unreliable because their early "grasshopper" prototype (for testing landing) exploded and at times. Also probably a good idea to note that these explosions all happened during their landing attempt, so in theory any payload onboard would have already been deployed. It's just the vehicle that would be lost. Of course they're still so early in the development cycle that Starship hasn't even attempted an orbital flight yet.
I get that it's weird watching these very early prototypes blow up so spectacularly and publicly, but that's the development model SpaceX has chosen. And we're not used to watching rockets being built and tested so out in the open. Personally I think it's exciting watching the progress they're making.
I'm just going to assume you're referring to Starship's various explosions. It's far too early in the Starship development cycle to draw any kind of conclusions about it's reliability.
Starship is a prototype. It's a completely new vehicle with completely new engines, and they're building it with the expectation that the early versions are going to blow up. It's like saying Falcon 9 is unreliable because their early "grasshopper" prototype (for testing landing) exploded and at times. Also probably a good idea to note that these explosions all happened during their landing attempt, so in theory any payload onboard would have already been deployed. It's just the vehicle that would be lost. Of course they're still so early in the development cycle that Starship hasn't even attempted an orbital flight yet.
I get that it's weird watching these very early prototypes blow up so spectacularly and publicly, but that's the development model SpaceX has chosen. And we're not used to watching rockets being built and tested so out in the open. Personally I think it's exciting watching the progress they're making.
> the Ariane 5 rockets (which will actually be launching the James Web Space Telescope) which has had 109 launches, and 5 of them ended in failure
I just read that they had one failure, though I can't find it. Does anyone have any reliable data (i.e., not Wikipedia)?
I just read that they had one failure, though I can't find it. Does anyone have any reliable data (i.e., not Wikipedia)?
http://www.spacelaunchreport.com/ariane5.html
The notes for the failures are at the bottom.
The notes for the failures are at the bottom.
That's how space travel development works. It doesn't take off; it crashes; it explodes; it fails to land; it works. From then on pretty much, it works.
What is that based on? How do you distinguish launch systems that just don't work well? Everything works in the end? That would make engineering much easier and less stressful!
I’m unaware of any launch system that gets many tries at failures - it either gets what needs to be done relatively quickly or it gets cancelled. The number of tries you get is usually single digits.
Everyone fails a few times at a minimum.
Everyone fails a few times at a minimum.
Falcon 9 (and Heavy) has not experienced any kind of mission failure since 2016, the latter period accounting for (if I'm counting right) 69% of its total launches including the Amos-6 pad failure (which did not actually launch). Its actual failure rate is 1.5%.
It's not a track record that deserves any more derision than its contemporaries. Doing so in such vague terms just makes you look like you don't know what you're talking about, which goes double if you're thinking not of F9, but rather of those big shiny rockets they've been blowing up in Boca Chica recently. That (Starship) is a development program.
It's not a track record that deserves any more derision than its contemporaries. Doing so in such vague terms just makes you look like you don't know what you're talking about, which goes double if you're thinking not of F9, but rather of those big shiny rockets they've been blowing up in Boca Chica recently. That (Starship) is a development program.
SpaceX launched three crews to the ISS within the last 12 months. In other words, they are trusted with payload with the highest caliber.
How can a comment be that ignorant yet presented in such a confident tone?
How can a comment be that ignorant yet presented in such a confident tone?
Such an exciting, and high stakes, and dramatically late and over-budget mission.
I am so amped for this telescope. I hope it exceeds my expectations.
It also looks like this location will be quite crowded in the future https://en.wikipedia.org/wiki/List_of_objects_at_Lagrange_po...
It also looks like this location will be quite crowded in the future https://en.wikipedia.org/wiki/List_of_objects_at_Lagrange_po...
It blows my mind that humans can get together and build something like this.
I was just watching YT channel “Primitive Technology” and it really puts things into perspective. From sticks and stones to bootstrapping a James Webb Telescope that’s gonna sit at a langrange point between the Earth and the Sun. Woah.
I was just watching YT channel “Primitive Technology” and it really puts things into perspective. From sticks and stones to bootstrapping a James Webb Telescope that’s gonna sit at a langrange point between the Earth and the Sun. Woah.
Interesting angle and this telescope really is a time machine.
Still better than a failed jet fighter. At least we will have working telescope. Even if all we get out of it are some photos for a wallpaper for PC. Still better value as something is better then nothing in this case.
Government red tape and contracting at its finest
Edit: Downvotes with no comments as to why... This thing is 24 years in development and 20x over budget. If thats not a failure of government contracting, budgeting, etc then idk what is: https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Cos... - Obviously the platform will be cool once they get it launched, but until then its just a money pit.
Edit: Downvotes with no comments as to why... This thing is 24 years in development and 20x over budget. If thats not a failure of government contracting, budgeting, etc then idk what is: https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Cos... - Obviously the platform will be cool once they get it launched, but until then its just a money pit.
I think you're getting downvoted because what you're saying doesn't match up with the wiki article you linked.
The original estimate was for $1.6 billion, in I'm guessing the 90s, and the estimate had been updated to $5 billion by the time it was formally confirmed for construction.
> The telescope was originally estimated to cost US$1.6 billion,[102] but the cost estimate grew throughout the early development and had reached about US$5 billion by the time the mission was formally confirmed for construction start in 2008.
So yes, it has been over budget, but by 2x-3x, not 20x, and that isn't adjusted for inflation.
Also, everything is just a money pit until it's launched/finished/etc.
The original estimate was for $1.6 billion, in I'm guessing the 90s, and the estimate had been updated to $5 billion by the time it was formally confirmed for construction.
> The telescope was originally estimated to cost US$1.6 billion,[102] but the cost estimate grew throughout the early development and had reached about US$5 billion by the time the mission was formally confirmed for construction start in 2008.
So yes, it has been over budget, but by 2x-3x, not 20x, and that isn't adjusted for inflation.
Also, everything is just a money pit until it's launched/finished/etc.
Adjusted for inflation it'd be about $2.5 billion this year. So it's almost exactly 2x.
According to the budget table, when the project started in 1997, the budget plan was 500 million. Today its close to 10 billion.
That was likely just a bare bones estimate and closer to the costs of initiating the project than the full cost of designing, building, and launching a satellite.
Based on this link, NASA hadn't even settled on a design/contractor in 1998.
https://esahubble.org/images/opo9820a/
Based on this link, NASA hadn't even settled on a design/contractor in 1998.
https://esahubble.org/images/opo9820a/
It's because this is a flippant, unhelpful attitude. If we were talking about building a mile of blacktop highway then such a casual observation about the overrun might be warranted.
But we're not talking about that. We're talking about building the first non-orbital space telescope in human history. To a certain extent, no one could know the actual cost ahead of time. It's one of those things you kind of have to do and it will cost what it will cost.
Was there waste I this project? Probably. But there's a good chance the overruns are dominated by true "found work" rather than waste.
In fact, this is exactly the kind of project you want handled by the government because the cost of failure is so high. In a project where you need to push the risk out as many decimal places as possible it is good to have an agency which can afford the overruns to do it.
But we're not talking about that. We're talking about building the first non-orbital space telescope in human history. To a certain extent, no one could know the actual cost ahead of time. It's one of those things you kind of have to do and it will cost what it will cost.
Was there waste I this project? Probably. But there's a good chance the overruns are dominated by true "found work" rather than waste.
In fact, this is exactly the kind of project you want handled by the government because the cost of failure is so high. In a project where you need to push the risk out as many decimal places as possible it is good to have an agency which can afford the overruns to do it.
"the first non-orbital space telescope"
There've been a few others, including Gaia (SEL-2 halo orbit -- same as JWST), and Kepler (heliocentric). [edit]: also Herschel (SEL-2)
https://en.wikipedia.org/wiki/Gaia_(spacecraft)#Launch_and_o...
https://en.wikipedia.org/wiki/Kepler_space_telescope#Orbit_a...
https://en.wikipedia.org/wiki/Herschel_Space_Observatory#Lau...
There've been a few others, including Gaia (SEL-2 halo orbit -- same as JWST), and Kepler (heliocentric). [edit]: also Herschel (SEL-2)
https://en.wikipedia.org/wiki/Gaia_(spacecraft)#Launch_and_o...
https://en.wikipedia.org/wiki/Kepler_space_telescope#Orbit_a...
https://en.wikipedia.org/wiki/Herschel_Space_Observatory#Lau...
Interesting. I assumed these were in orbit like other satellites. I didn't realize they operated from the Lagrange points. Thanks.
What basis do you have for blaming government contracting? Lots of projects built by lots of organizations are very late and over-budget. One difference between government and private industry is that the government has the resources and motivation to persist - they aren't in it for profit. If this was a private company, it may have been canceled long ago as unprofitable. Is that a preferable outcome?
In fact, wasn't the JWST built by Northrop Grumman to a great extent? Why not blame them?
EDIT: It's hard to criticize government contracting in the same context as NASA, which has taken more risks and achieved new things far beyond any private organization in history. NASA has operations throughout the Solar System, and in interstellar space. They are the only organization to put humans on the moon - 50 years ago! Can anyone else say anything that? SpaceX?
In fact, wasn't the JWST built by Northrop Grumman to a great extent? Why not blame them?
EDIT: It's hard to criticize government contracting in the same context as NASA, which has taken more risks and achieved new things far beyond any private organization in history. NASA has operations throughout the Solar System, and in interstellar space. They are the only organization to put humans on the moon - 50 years ago! Can anyone else say anything that? SpaceX?
The original budget was a guess. They didn't know how much the telescope would cost because the required technology didn't actually exist at the start of the budgeting process 24 years ago.
Now that technology does exist, and it turns out it's quite expensive, which drove most of the cost increases. However, since then the budget increases have generally paced with inflation.
Source: your citation.
Now that technology does exist, and it turns out it's quite expensive, which drove most of the cost increases. However, since then the budget increases have generally paced with inflation.
Source: your citation.
Further to your point, now that the pioneering work has been done, a similar piece of equipment could likely be built at a significantly reduced cost.
Your comment doesn't add anything to the conversation. But for anyone else that is actually interested: the cost of JWST is really not that extravagant considering how much more capability it provides compared to HST.
> Not even including its four space-shuttle servicing missions, Hubble cost $4 billion or $5 billion in today's dollars just to build and launch," Dressler notes. "Here we are, building a telescope that is almost seven times bigger, it is cryogenic, it is operating 1.5 million kilometres away, and it is costing the same amount as Hubble did, if not less. That is remarkable, and this is probably the biggest scale on which we will consider building such things in this country."
From this article: https://www.nature.com/articles/4671028a
> Not even including its four space-shuttle servicing missions, Hubble cost $4 billion or $5 billion in today's dollars just to build and launch," Dressler notes. "Here we are, building a telescope that is almost seven times bigger, it is cryogenic, it is operating 1.5 million kilometres away, and it is costing the same amount as Hubble did, if not less. That is remarkable, and this is probably the biggest scale on which we will consider building such things in this country."
From this article: https://www.nature.com/articles/4671028a
The thing with this kind of project, we're not punching out the 10 millionth Honda Civic or something. There's a tremendous amount of stuff here that's never been done before. There's no good way to have an accurate estimate for how much it will cost. You pretty much have to just keep spending until you get it right. This works the same way whether it's Government or Private Industry. Just ask Intel how far over budget they've gone getting EUV working.
Another way to put it is that it’s a jobs program.
Edit: what’s with the downvotes? I would like to understand what the disagreement is here. Any gov program can be split up into two parts. One, the actual cost as dictated by the market economy, and second, the additional costs for delays, bureaucracy, etc which usually tends to be multiples of the actual costs. This money goes into paying salaries without actually making any progress. Hence the jobs program. What’s there to disagree here? Is this argument somehow belonging to a particular political spectrum? Downvotes are fine but I’d like to gain some understanding of where my thoughts are not aligned with you. Please explain your position.
Edit: what’s with the downvotes? I would like to understand what the disagreement is here. Any gov program can be split up into two parts. One, the actual cost as dictated by the market economy, and second, the additional costs for delays, bureaucracy, etc which usually tends to be multiples of the actual costs. This money goes into paying salaries without actually making any progress. Hence the jobs program. What’s there to disagree here? Is this argument somehow belonging to a particular political spectrum? Downvotes are fine but I’d like to gain some understanding of where my thoughts are not aligned with you. Please explain your position.
I would say "PR program" more than jobs program. NASA is the public face of the DoD/NRO spy satellite tech. Most of them are just looking back toward Earth at you and I instead of looking out into space. Compare to these programs which had over 4x the budget of JWST in 2004: https://en.wikipedia.org/wiki/Key_Hole
e: For example, KH-11 shares parts with the Hubble Space Telescope: https://en.wikipedia.org/wiki/KH-11_Kennen
'KH-11s are believed to resemble the Hubble Space Telescope in size and shape, as the satellites were shipped in similar containers. Their length is believed to be 19.5 meters, with a diameter of up to 3 meters.[5][23] A NASA history of the Hubble,[24] in discussing the reasons for switching from a 3-meter main mirror to a 2.4-meter design, states: "In addition, changing to a 2.4-meter mirror would lessen fabrication costs by using manufacturing technologies developed for military spy satellites.'
Notice how that says KH-11s, plural.
e: For example, KH-11 shares parts with the Hubble Space Telescope: https://en.wikipedia.org/wiki/KH-11_Kennen
'KH-11s are believed to resemble the Hubble Space Telescope in size and shape, as the satellites were shipped in similar containers. Their length is believed to be 19.5 meters, with a diameter of up to 3 meters.[5][23] A NASA history of the Hubble,[24] in discussing the reasons for switching from a 3-meter main mirror to a 2.4-meter design, states: "In addition, changing to a 2.4-meter mirror would lessen fabrication costs by using manufacturing technologies developed for military spy satellites.'
Notice how that says KH-11s, plural.
By that logic, so is the military, public schools and highway maintenance.
Any over budget and poorly run government program I see it as a jobs program. F-35, CalTrain, NASA SLS, etc.
This is in stark contrast with partnerships with private industries. For eg DARPA + Moderna or NASA + SpaceX.
This is in stark contrast with partnerships with private industries. For eg DARPA + Moderna or NASA + SpaceX.
While I am as critical of government overspending as anyone, this comparison misses some important nuances.
Let's take the SpaceX example. SpaceX is great in terms of pushing innovation. But there would be no SpaceX without NASA or other government entities. They need those tax dollars (especially early on) to survive. And when they lose a government payload, the government takes something to the tune of 80% of the loss because they are self-insured. This has the effect of SpaceX farming out their risk to the government.
But this is one of the areas where the government excels. Namely, taking large risks in nascent fields where the risk is too big for private companies to balance against the benefit by themselves. But the complexities and unknowns that create that risk is also the very same thing that creates the budget and schedule risk as well.
Let's take the SpaceX example. SpaceX is great in terms of pushing innovation. But there would be no SpaceX without NASA or other government entities. They need those tax dollars (especially early on) to survive. And when they lose a government payload, the government takes something to the tune of 80% of the loss because they are self-insured. This has the effect of SpaceX farming out their risk to the government.
But this is one of the areas where the government excels. Namely, taking large risks in nascent fields where the risk is too big for private companies to balance against the benefit by themselves. But the complexities and unknowns that create that risk is also the very same thing that creates the budget and schedule risk as well.
I fail to see the difference. Private contracts often go over budget. The F-35 itself is full of privately contracted parts. Many public/private partnerships contracts are even no bid, meaning they are essentially uncompetitive. Whether the government hires people directly to do a job or whether they contract it out is equally distortionary. By allocating tax dollars to a public rocket lab or to a private rocket company you are increasing the demand for rocket engineers and thus creating a "rocket engineer" jobs program.
All those projects were built by private industry, including the latter two.
That’s true. I concede my point.
what's the biggest risk? rocket failure during takeoff or telescope malfunction?
Ariane 5 rockets have accumulated 109 launches since 1996, 104 of which were successful, yielding a 95.4% success rate. Between April 2003 and December 2017, Ariane 5 flew 82 consecutive missions without failure, but the rocket suffered a partial failure in January 2018
from: https://en.wikipedia.org/wiki/Ariane_5
from: https://en.wikipedia.org/wiki/Ariane_5
There are several big risks. It's impossible to rank them in a credible way.
Obviously there are all the usual launch risks. The cryogenics system has had a lot of development problems. The deployment is staggeringly complex and involves components that are not known for their robustness. Finally there is no repair option; one critical things goes wrong or is found to be misdesigned and that's it.
Obviously there are all the usual launch risks. The cryogenics system has had a lot of development problems. The deployment is staggeringly complex and involves components that are not known for their robustness. Finally there is no repair option; one critical things goes wrong or is found to be misdesigned and that's it.
I believe the unfurling of the solar panels is one of the tricky parts.
Most rockets these days are pretty reliable. Ariane 5 only had one partial failure in 20 years I believe.
Going to be amazing if this thing can actually unfurl, but I'm scared.
I used to work at JPL, and I was there when the sky-crane (the system currently used to land rovers on Mars) was first proposed back in the late 90s. I remember thinking to myself, "That is the craziest idea I have ever heard, there is no way that could possibly work." But it did.
Never bet against NASA engineers. Sure, they have the odd high-profile screwup, but on the whole they are shockingly competent.
Never bet against NASA engineers. Sure, they have the odd high-profile screwup, but on the whole they are shockingly competent.
Do you know if there is any test footage of that anywhere? That's, to me anyway, the second most amazing thing about the sky crane...that I can't find a single frame of it in operation on earth.
Earth physics are different from Mars physics. What works there wouldn't work here; can't just try it out and see if it works.
Sure the final mission configuration isn't exactly what they would test, but the differences in the sky crane maneuver on Mars and Earth would be relatively easy to factor in (ok, that might be an exaggeration, but its doable). There is a ton of control development that would need to be sorted out so they knew how to integrate it all. For example, I had heard that the primary indicator that the rover had touched down simply watching the throttle on the closed loop flight control system. When it throttled down it meant the rockets were no longer suspending the weight of the rover. If true, I would think you would want to test that quite a bit...
FWIW they tested missile defense 'kill vehicles' on the ground and they will operate at or near orbital velocity in space. The main 'hover thruster' would likely be completely unnecessary in a live exercise:
https://www.youtube.com/watch?v=KBMU6l6GsdM
FWIW they tested missile defense 'kill vehicles' on the ground and they will operate at or near orbital velocity in space. The main 'hover thruster' would likely be completely unnecessary in a live exercise:
https://www.youtube.com/watch?v=KBMU6l6GsdM
would it have had enough thrust to work in earth gravity?
Sorry I have no idea.
Same feelings here!
Ever since it was announced I have been anxious about it all going to plan.
Sometimes I put myself in the shoes of the engineers and controllers, and I can’t imagine how nerve wracking it must be, waiting and waiting!
The thing could simply blow up on the launch pad, for goodness sake!
Ever since it was announced I have been anxious about it all going to plan.
Sometimes I put myself in the shoes of the engineers and controllers, and I can’t imagine how nerve wracking it must be, waiting and waiting!
The thing could simply blow up on the launch pad, for goodness sake!
Arianespace fat-fingering an Ariane 5 into the wrong orbit recently didn't exactly help with my anxiety...
https://spacenews.com/bad-coordinates-led-ariane-5-astray-la...
(OTOH, I'm positive that particular issue won't reoccur)
https://spacenews.com/bad-coordinates-led-ariane-5-astray-la...
(OTOH, I'm positive that particular issue won't reoccur)
> The thing could simply blow up on the launch pad, for goodness sake!
exactly, I’ve wondered why they don’t build e.g. 2 or 3 of them in tandem since it’d likely be cheaper/easier to do up front vs after the fact if things went wrong. They would then have the additional telescopes if things went right, offering even greater access.
exactly, I’ve wondered why they don’t build e.g. 2 or 3 of them in tandem since it’d likely be cheaper/easier to do up front vs after the fact if things went wrong. They would then have the additional telescopes if things went right, offering even greater access.
You're correct - building constellations is definitely much cheaper.
For an observational/capability platform such as for DoD or NOAA, making a large number in a series makes sense. For a research platform (NASA/NSF) that same idea doesn't apply, since science objectives dominate the discussion.
For an observational/capability platform such as for DoD or NOAA, making a large number in a series makes sense. For a research platform (NASA/NSF) that same idea doesn't apply, since science objectives dominate the discussion.
With Mars landers, they do build two of them. When they have an issue with the one on Mars, they break out the one here on Earth and start debugging. When they have a solution that works, then they know what to do with the one on Mars.
I don't know if that would work on telescopes, though - I suspect that the copy wouldn't have the full optics installed.
I don't know if that would work on telescopes, though - I suspect that the copy wouldn't have the full optics installed.
See my other comment: https://news.ycombinator.com/item?id=27767223
The timelines on this kind of project are so long spares don't make sense vs trying again with a new and updated design.
The timelines on this kind of project are so long spares don't make sense vs trying again with a new and updated design.
I don't know why, but I've had this gut-wrenching feeling for a couple of years now that Something Terrible is going to happen to this before it gets into position at L2.
I really hope not, obviously, but this seems like an All Your Eggs In One Basket lesson in the making.
We need to commodify this tech, make them somewhat disposable, and sent oodles of them up on Starships.
I really hope not, obviously, but this seems like an All Your Eggs In One Basket lesson in the making.
We need to commodify this tech, make them somewhat disposable, and sent oodles of them up on Starships.
Using 3 COTS (Commercial Off The Shelf) components with 90% reliability can ensure 99.9% redundancy instead of having a Unique very reliable and even costlier 99.9% custom component can really lower costs.
But it can happen only if mass is not a constraint.
From Casey Handmer's blog: https://caseyhandmer.wordpress.com/2021/03/04/sls-what-now/
The Perseverance Mars rover cost $2.4 billion, which works out to a few thousand salaries for just under a decade. Thousands of people are needed to build this rover because landing stuff on Mars is so hard that subsystem masses must be tracked to a tenth of a gram, on a system that weighs a tonne. The whole thing is meticulously handcrafted from custom silicon, PCBs, titanium tubes, motors, cameras, and other awe-inspiring instruments. Starship will be able to land 100 of them per flight. Now what? How can NASA feed a team that makes one feather light rover per decade for a billion dollars if the demand just jumped by a factor of a thousand and the unit cost fell by the same amount? Set up a production line? Work out how to make them with a team of ten? Build one every two weeks?
From Casey Handmer's blog: https://caseyhandmer.wordpress.com/2021/03/04/sls-what-now/
The Perseverance Mars rover cost $2.4 billion, which works out to a few thousand salaries for just under a decade. Thousands of people are needed to build this rover because landing stuff on Mars is so hard that subsystem masses must be tracked to a tenth of a gram, on a system that weighs a tonne. The whole thing is meticulously handcrafted from custom silicon, PCBs, titanium tubes, motors, cameras, and other awe-inspiring instruments. Starship will be able to land 100 of them per flight. Now what? How can NASA feed a team that makes one feather light rover per decade for a billion dollars if the demand just jumped by a factor of a thousand and the unit cost fell by the same amount? Set up a production line? Work out how to make them with a team of ten? Build one every two weeks?
They should put that team to work on next-generation tech, the stuff that's not yet a commodity. They can start working on habitat construction materials and hardware, for instance.
Although it is interesting to consider that we've put a lot of expense into optimizing payloads that, in retrospect, would have been smarter to put into better launch vehicles. SpaceX probably isn't going to spend $2 billion developing Starship (even if Boeing would have.)
Although it is interesting to consider that we've put a lot of expense into optimizing payloads that, in retrospect, would have been smarter to put into better launch vehicles. SpaceX probably isn't going to spend $2 billion developing Starship (even if Boeing would have.)
IIRC, SpaceX is getting $2.89B from NASA for the Artemis lander, which proposal is based on Starship. Although, the GAO put that on hold recently, after complaints from BlueOrigin and Dynetics. Hardly surprising, I guess.
an important consideration is that SpaceX hasn't in fact, gotten 100 tons of equipment to mars yet.
I think this part of the problem though. We don't believe we can really do anything at this point so we have turned everything into a stochastic process with multiple draws needed and it gives everyone an out when things don't work.
"Oops, JWST blew up, guess we just got unlucky with that single draw from the urn. Shouldn't have put all our eggs in one basket. "
Just do it. No more urn thinking. Just launch , get in orbit and blow our minds with the data that is sent back. I don't want to hear about anything less than that.
"Oops, JWST blew up, guess we just got unlucky with that single draw from the urn. Shouldn't have put all our eggs in one basket. "
Just do it. No more urn thinking. Just launch , get in orbit and blow our minds with the data that is sent back. I don't want to hear about anything less than that.
Just want launch to be over so I don't have to deal with JW news anxiety anymore.
I almost want the unfurling to get stuck, just b/c SpaceX launching a manned Starship out to a LaGrange point to hotfix it would be super cool.
Fly out there, spacewalk over, give it a little jiggle, looks good, fly home.
It would be like driving six hours to push a power button, but epic.
It would be like driving six hours to push a power button, but epic.
Nice. On track to beat https://xkcd.com/2014/
Looks like it just gave Elon Musk some ideas
https://www.reddit.com/r/spacex/comments/ofqm8o/elon_musk_us...
https://www.reddit.com/r/spacex/comments/ofqm8o/elon_musk_us...
I was watching a presentation given by the MGT project manager at cal tech and he mentioned that the MGT has a lower diffraction limit than the JWST. I think “diffraction limit” was the term he used, I don’t remember. The idea was that the images are supposed to be sharper. I was very confused about that. Why build JWST if MGT is going to maker cleaner images?
The diffraction limit is the fundamental resolution limit of a telescope. This is the size of "spot" that will be created on the camera sensor for a single point of light like a star [1].
Its easy to calculate, just take the wavelength of the of light you want to observe and divide it by the diameter of the primary mirror (and multiply by ~1.2).
For example, for JWST observing in the mid-infrared, say 4micron, with a 6.5 meter diameter mirror, has a resolution limit of: 4e-6 / 6.5 = 6.15e-7 Or about 0.6 micro-radians (astronomers would normally use arcseconds but leaving in radians for clarity).
This is just the theoretical limit though, it's reduced by any imperfections in the optics, and for telescopes on the ground, it's limited by the blurring of the Earth's atmosphere to about 4 micro-radians.
For narrow fields of view, however, ground-based telescopes can use adaptive optics to compensate for this shimmering/blurring in real time and reach close to their theoretical diffraction limit. Plus, they can be much bigger since we don't have to launch them into space. I'm not familiar with the MGT but this might be how it will surpass JWST in terms of resolution (which again also depends on the wavelength).
For infrared observations though, a huge effect that can't be compensated for is sensitivity. At mid-infrared wavelengths, the Earth's atmosphere actually glows and makes it much harder to see faint sources. This is one of the ways JWST will really shine.
[1] Note however that you can still do things like measure the position of an object to less than the diffraction limit using e.g. centroiding. But you can't tell if there are two objects or one below this limit.
Its easy to calculate, just take the wavelength of the of light you want to observe and divide it by the diameter of the primary mirror (and multiply by ~1.2).
For example, for JWST observing in the mid-infrared, say 4micron, with a 6.5 meter diameter mirror, has a resolution limit of: 4e-6 / 6.5 = 6.15e-7 Or about 0.6 micro-radians (astronomers would normally use arcseconds but leaving in radians for clarity).
This is just the theoretical limit though, it's reduced by any imperfections in the optics, and for telescopes on the ground, it's limited by the blurring of the Earth's atmosphere to about 4 micro-radians.
For narrow fields of view, however, ground-based telescopes can use adaptive optics to compensate for this shimmering/blurring in real time and reach close to their theoretical diffraction limit. Plus, they can be much bigger since we don't have to launch them into space. I'm not familiar with the MGT but this might be how it will surpass JWST in terms of resolution (which again also depends on the wavelength).
For infrared observations though, a huge effect that can't be compensated for is sensitivity. At mid-infrared wavelengths, the Earth's atmosphere actually glows and makes it much harder to see faint sources. This is one of the ways JWST will really shine.
[1] Note however that you can still do things like measure the position of an object to less than the diffraction limit using e.g. centroiding. But you can't tell if there are two objects or one below this limit.
I'll add to this that resolution is not the only metric by which you can judge a telescope. One major advantage that space telescopes have is that their environment is much more stable, making calibration (for example, of the flux of a source) easier. On Earth, the weather changes from night to night, or even from minute to minute. You're effectively looking through a constantly changing, semi-opaque filter - the atmosphere.
Ground-based telescopes have their own advantages, like the fact that they can be much larger and therefore can collect much more light.
This is just to say that both space- and ground-based telescopes are useful, and have their own strengths.
Ground-based telescopes have their own advantages, like the fact that they can be much larger and therefore can collect much more light.
This is just to say that both space- and ground-based telescopes are useful, and have their own strengths.
I'm just a rube but in general there are two issues:
1 - the atmosphere distorts and filters out a lot of light in various wavelengths. MGT likely has better resolution, but only for light that reaches it.
2 - JWST is primarily for infrared. Given blackbody radiation of the equipment itself can create a bunch of noise there, it's important to keep the equipment as cool as possible.
1 - the atmosphere distorts and filters out a lot of light in various wavelengths. MGT likely has better resolution, but only for light that reaches it.
2 - JWST is primarily for infrared. Given blackbody radiation of the equipment itself can create a bunch of noise there, it's important to keep the equipment as cool as possible.
MGT is limited to the light that filters through the atmosphere. JWST will be tuned to longer wavelengths (redshifted older objects) that can only be seen in cold space.
> JWST will be tuned to longer wavelengths (redshifted older objects) that can only be seen in cold space.
As I understand it: We're placing it at L2 specifically for that reason, to isolate it from other radiation.
As I understand it: We're placing it at L2 specifically for that reason, to isolate it from other radiation.
I believe there are some kinds of photography that can only be done outside the atmosphere.
Edit: see: https://en.m.wikipedia.org/wiki/James_Webb_Space_Telescope, particularly comparison with other telescopes. Seems the primary reason is for infrared photography.
Edit: see: https://en.m.wikipedia.org/wiki/James_Webb_Space_Telescope, particularly comparison with other telescopes. Seems the primary reason is for infrared photography.
Many wavelengths of light are simply blocked by the Earth's atmosphere. If you want to see them you have to go above the atmosphere.
Maybe MGT isn't limited by diffraction but rather by atmospheric distortion (or residual distortion, because presumably they do what they can to correct it)? Just a guess, I'm not an astronomer.
godspeed jwst team! find me an alienz!
OMFG!!!! I’m so excited… let’s go!!!!!!!
Does anyone remember the initial proposals for this. The cost was supposed to be $500M. At most something like $1B.
Given this is standard govt contracting - I'm sure it's come out much higher.
Given this is standard govt contracting - I'm sure it's come out much higher.
Even 5B for a novel, and uniquely powerful observation platform would be a bargain!
When you are engineering a unit of 1 pushing the boundaries of science, with multiple conflicting constraints, funded by a variety of self-interested stakeholders, and are forced to do commercial production, rather than govt production, even when it is most cost effective, it isn't like you are heading towards lowest cost, technically acceptable.
When you are engineering a unit of 1 pushing the boundaries of science, with multiple conflicting constraints, funded by a variety of self-interested stakeholders, and are forced to do commercial production, rather than govt production, even when it is most cost effective, it isn't like you are heading towards lowest cost, technically acceptable.
It's easy to throw these big numbers around, but do you ever stop to consider the actual cost? Let's do some back-of-the envelope calculations to help us consider the human cost of a 5B telescope.
The Median US household income is ~68,000/year[0] The Average income tax paid by someone in the 50-75K income range is $4,600/year.[1] The average working career is probably around 40 years.
5,000,000,000 / 4,600 / 40 = 27,173
To fund a $5B project, 27,173 people (more, actually, since this is household data) could have worked for their entire working lives, with every dime of federal income tax being spent on that one project!
I agree that the JWST is a worthwhile project, but let's not pretend that it's a bargain.
[0]https://www.census.gov/library/publications/2020/demo/p60-27... [1]https://www.fool.com/taxes/how-much-does-the-average-america...
The Median US household income is ~68,000/year[0] The Average income tax paid by someone in the 50-75K income range is $4,600/year.[1] The average working career is probably around 40 years.
5,000,000,000 / 4,600 / 40 = 27,173
To fund a $5B project, 27,173 people (more, actually, since this is household data) could have worked for their entire working lives, with every dime of federal income tax being spent on that one project!
I agree that the JWST is a worthwhile project, but let's not pretend that it's a bargain.
[0]https://www.census.gov/library/publications/2020/demo/p60-27... [1]https://www.fool.com/taxes/how-much-does-the-average-america...
Using the same numbers, 3,824,456 people worked their entire lives to fund the USA's military for 2021.
https://www.defense.gov/Newsroom/Releases/Release/Article/26...
https://www.defense.gov/Newsroom/Releases/Release/Article/26...
I think that NASA's budget, unlike many other federal agencies, is actually highly beneficial to US Taxpayers due to the large amount of IP/new inventions generated. Similar to DARPA, there are huge ROI factors that come in from an organization that researches, conducts science and engineering efforts on a massive scale, resulting in technologies that consumers can use economically.
https://en.wikipedia.org/wiki/NASA_spinoff_technologies
NASA's budget is one of the smallest slices of the federal budget, and for that amount we receive a great deal back in benefits.
https://en.wikipedia.org/wiki/Budget_of_NASA
Due to the huge amount of technologies generated, and refined from these large prestige missions, I do not consider them to be a waste of funding.
One great example are the weather satellites generated by the NASA/NOAA partnership, such as GOES-R, and JPSS, and their predecessor missions in GOES & POES, to name a few. While they are very expensive they equip meteorologists with the rich data needed to make accurate observations. These observations directly impact human life, both by guiding evacuation decisions, knowing tornado tracks, and also, farming decisions. This same data is used for supply chain management, and there are a number of other uses for it.
Although many commercial media sources will be happy to provide you a weather feed, they often do not tell you that they have a backend connection to NASA, NESDIS and NWS, in order to provide their own weather data, or data from a research satellite. Or they'll provide you a customized photo which is actually a tailored version of imagery from GOES-*.
Because of the incalculable costs of an earth impacting asteroid, or a Carrington-dwarfing electromagnetic storm https://en.wikipedia.org/wiki/Carrington_Event , outward looking to see more of the cosmos is one of the best things we can do to ensure our survival as a species. The more we look out, the more we are able to prepare for such an event.
https://en.wikipedia.org/wiki/NASA_spinoff_technologies
NASA's budget is one of the smallest slices of the federal budget, and for that amount we receive a great deal back in benefits.
https://en.wikipedia.org/wiki/Budget_of_NASA
Due to the huge amount of technologies generated, and refined from these large prestige missions, I do not consider them to be a waste of funding.
One great example are the weather satellites generated by the NASA/NOAA partnership, such as GOES-R, and JPSS, and their predecessor missions in GOES & POES, to name a few. While they are very expensive they equip meteorologists with the rich data needed to make accurate observations. These observations directly impact human life, both by guiding evacuation decisions, knowing tornado tracks, and also, farming decisions. This same data is used for supply chain management, and there are a number of other uses for it.
Although many commercial media sources will be happy to provide you a weather feed, they often do not tell you that they have a backend connection to NASA, NESDIS and NWS, in order to provide their own weather data, or data from a research satellite. Or they'll provide you a customized photo which is actually a tailored version of imagery from GOES-*.
Because of the incalculable costs of an earth impacting asteroid, or a Carrington-dwarfing electromagnetic storm https://en.wikipedia.org/wiki/Carrington_Event , outward looking to see more of the cosmos is one of the best things we can do to ensure our survival as a species. The more we look out, the more we are able to prepare for such an event.
You can get a pretty good idea of quality of project management based on how well or poorly they estimated project baseline costs at outset.
These are linked - incompetence in estimating costs / complexity = incompetence in execution = insane cost overruns.
And you would get far more science with 5 $2B projects then one project like this. And if this thing has a launch of deployment problem all eggs in one basket. If there are cost overruns and delays, also all eggs in a basket and no other options.
These are linked - incompetence in estimating costs / complexity = incompetence in execution = insane cost overruns.
And you would get far more science with 5 $2B projects then one project like this. And if this thing has a launch of deployment problem all eggs in one basket. If there are cost overruns and delays, also all eggs in a basket and no other options.
Here is a nice table with the history of the budget:
https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Cos...
https://en.wikipedia.org/wiki/James_Webb_Space_Telescope#Cos...
Clicking through we get this
"JWST is now estimated to cost approximately $9.7 billion and launch in October 2021, which represents cost growth of 95 percent and 88 months of schedule delays since the project’s cost and schedule baselines were first established in 2009."
So around $10B. Amazing.
"JWST is now estimated to cost approximately $9.7 billion and launch in October 2021, which represents cost growth of 95 percent and 88 months of schedule delays since the project’s cost and schedule baselines were first established in 2009."
So around $10B. Amazing.
I wonder what the marginal cost would be to build a second one?
If you thought estimating software projects was hard, try estimating a friggin space launch.
Fact boy covered it a few weeks ago:
https://www.youtube.com/watch?v=CowU0QK0Pjs&ab_channel=Megap...
From what i remember this project has been running since around the time of Hubble
Still.... Can't wait for it to get up there, money and time well spent!
https://www.youtube.com/watch?v=CowU0QK0Pjs&ab_channel=Megap...
From what i remember this project has been running since around the time of Hubble
Still.... Can't wait for it to get up there, money and time well spent!
That's pretty amazing. A financial black hole.
A cool project, but if you think of the thousands of folks who didn't get funding so this thing could gobble everything up - these projects really become crazy budget wise (SLS did the same path).
I wish they would do pay for performance deals. We'll give you $4B if you put a telescope in space of X size that meets some basic specs.
If you look at commercial side, space imaging (earth facing) has just exploded and the cost side has gotten very very good. So it's clear you can get optics and sensing into space for a lot less.
A cool project, but if you think of the thousands of folks who didn't get funding so this thing could gobble everything up - these projects really become crazy budget wise (SLS did the same path).
I wish they would do pay for performance deals. We'll give you $4B if you put a telescope in space of X size that meets some basic specs.
If you look at commercial side, space imaging (earth facing) has just exploded and the cost side has gotten very very good. So it's clear you can get optics and sensing into space for a lot less.
$1B? That gone last a year tops.
This documentary was produced by Northrop Grumman Corporation -- the builders of JWST under a NASA contract.