Astronauts take shelter in Starliner, other spacecraft after satellite breakup(space.com)
space.com
Astronauts take shelter in Starliner, other spacecraft after satellite breakup
https://www.space.com/iss-astronauts-shelter-return-spacecraft-satellite-breakup
136 comments
How much shielding exactly is needed to defend one item moving at 17,500mph vs another moving towards it at 17,500. I agree propellant will become increasingly valuable but durable against impact seems almost fleeting of a goal
Whipple shields are effective and require less mass than one would imagine.
https://en.wikipedia.org/wiki/Whipple_shield
https://en.wikipedia.org/wiki/Whipple_shield
Kind of curious that at those high speeds bigger might be better, since the impact is spread over a larger area, and energy scales only linearly with mass.
This seems fallacious to me. Energy scales linearly with mass, so an object that is twice as big, is twice as bad. It probably isn't even twice the area, unless it's a flat sheet hitting broadside on - but even if it were, that's still at best the same as getting hit twice. Or are you saying that gluing two small pieces of debris together render them less harmful?
One wonders if we will then have lots of big robust space junk.
Perhaps. We'll also have big robust space junk removers
I always like to bring up the anime Planetes [0] when this is mentioned. I enjoyed the show overall but the core concept (space debris removal) was/is the main pull for me.
[0] https://en.m.wikipedia.org/wiki/Planetes
[0] https://en.m.wikipedia.org/wiki/Planetes
Iss has whipple shields on parts of it, lightweight compared to something like plate armor, to protect against very small debris.
As far as I understood it, plate armor would help very little against things moving at orbital speeds. Either it penetrates or it creates spalling on the other side. Either option isn't particularly nice.
[deleted]
This is actually something that happens fairly regularly. Sometimes they even rotate the space station so the smallest frontal area is facing the debris cloud.
It's not. Shelter actions are pretty rare.
Sounds stressful...Wake up, shower, dress, then have breakfast with your ISS colleagues, while keeping up with the latest edition of the Orbital Debris News!
Orbital Debris Quarterly News: https://orbitaldebris.jsc.nasa.gov/quarterly-news/pdfs/ODQNv...
Nasa Orbital Debris Program: https://orbitaldebris.jsc.nasa.gov/quarterly-news/#
Orbital Debris Quarterly News: https://orbitaldebris.jsc.nasa.gov/quarterly-news/pdfs/ODQNv...
Nasa Orbital Debris Program: https://orbitaldebris.jsc.nasa.gov/quarterly-news/#
Slightly tongue in cheek, but the astronauts on board are not going to be the ones doing the mission planning around debris checks - that will be coordinated from the ground.
What does it take to create a magnetic shield? Given unlimited rare earth metals and such
If you would limit to debris up to 250 grams, and not forgetting they arrive at a speed of at least 10 to 15 km/s, you would need a magnetic field of 2 to 4 Tesla. That is more than inside an MRI machine. Not feasible....
I interned with GE a while back maintaining their MRIs around sf Bay Area. Think most machines are 1.5T (tesla) with a large minority being 3T. Believe there are 7T machines used for veterinary research/care.
Thank you for the mental image of a horse inside an MRI machine before his big race day
How about just a sacrificial shield well in front of the station along its orbital path?
and/or a weaker magnetic one, also further ahead (further ahead would allow for deflecting slightly at lower power surely).
Problem #1 with the ISS having a shield "out front" - both the station and things that might hit it are traveling ~8km/sec. With the latter approaching from random-ish directions. That means the shield needs to cover a ~180 degree arc in front of the most of the ISS. (Which still would not intercept everything.) At such a size, even a pretty-very thin shield would have a huge mass.
Problem #2 - at those velocities, even puny bits of debris can punch through serious thicknesses of armor. (The "high velocity" shells that modern tanks use to kill each other are slow-pitch softballs by comparison.) And the "friendly fire shotgun blast" of debris created when a small piece of orbital junk goes through the shield can be far deadlier than that bit of junk would have been all by itself.
Problem #2 - at those velocities, even puny bits of debris can punch through serious thicknesses of armor. (The "high velocity" shells that modern tanks use to kill each other are slow-pitch softballs by comparison.) And the "friendly fire shotgun blast" of debris created when a small piece of orbital junk goes through the shield can be far deadlier than that bit of junk would have been all by itself.
aerogel? plus something in front of it to fragment the larger bits? https://ntrs.nasa.gov/citations/20130012682 found this idea searching for that actually..
It certainly would not be a point-defense system, but...I'd suggest placing a bunch of maneuverable little satellites in LEO, each one capable of making & high-precision dropping smallish cubes of a fast-evaporating aerogel. Game plan: Have those satellites drop cubes in front dangerous little bits of LEO space junk, to drop each bit of junk's perigee to the Kármán line. No need to match orbits, and you don't need to care (much) about debris from the high-velocity collisions, since all of that will reenter or evaporate within an hour.
The problem is you need a lot of fuel and delta-v for that. IMO lasers is a much better solution.
High-power thermal laser ablates a key portion of the space-junk to slightly change its trajectory and preferably help deorbit it. All you need is energy since the reaction-mass comes from the space-junk itself.
Maybe you could combine the ideas and instead of ablating to deorbit, you modify the space-junk orbits to collide with a large aerogel satellite. You could potentially even boost it in the process.
High-power thermal laser ablates a key portion of the space-junk to slightly change its trajectory and preferably help deorbit it. All you need is energy since the reaction-mass comes from the space-junk itself.
Maybe you could combine the ideas and instead of ablating to deorbit, you modify the space-junk orbits to collide with a large aerogel satellite. You could potentially even boost it in the process.
> The problem is you need a lot of fuel and delta-v for that.
Why? If the Bit O'Junk is within ~90% of its apogee, and it hits the aerogel cube at more than ~90 degrees, the impact will yield a fatal drop in Mr. O'Junk's perigee. Ion thrusters on the cube-laying satellites, high-precision orbital tracking, and a few racks of computers on the ground (to calculate orbits and impacts) should be enough. Low-powered lasers would probably be useful in the precision-tracking systems.
Blasting space-junk with high-powered lasers is cool...but those immediately get into issues with dual-use, space weapons treaties, and arms race scenarios.
Why? If the Bit O'Junk is within ~90% of its apogee, and it hits the aerogel cube at more than ~90 degrees, the impact will yield a fatal drop in Mr. O'Junk's perigee. Ion thrusters on the cube-laying satellites, high-precision orbital tracking, and a few racks of computers on the ground (to calculate orbits and impacts) should be enough. Low-powered lasers would probably be useful in the precision-tracking systems.
Blasting space-junk with high-powered lasers is cool...but those immediately get into issues with dual-use, space weapons treaties, and arms race scenarios.
(Corrections: "within ~90% of its apogee" should be "within ~45% of its apogee", and "hits the aerogel cube at more than ~90 degrees" should be "hits the aerogel cube at more than ~135 degrees". In both cases, the useful arc is ~90 degrees.)
I mean just delta-v to do the intercept in the first place. I suppose you could choose space junk that is already on a near intercept with the aerogel dispenser satellite or use something like spin deployment to launch the gels.
Can aerogel be manufactured by the satellite itself? That would be pretty cool. It also seems nearly as effective as a weapon though, a spy satellite with a camera or solar panels caked with aerogel is as good as destroyed.
Can aerogel be manufactured by the satellite itself? That would be pretty cool. It also seems nearly as effective as a weapon though, a spy satellite with a camera or solar panels caked with aerogel is as good as destroyed.
I'm using "intercept" to mean "extremely near miss, at high relative velocities". With the quasi-chaotic nature of orbits, that's easy for our rack of orbit-calculating computers to arrange - using only a few well-timed little nudges from the Killer Satellite's ion thrusters. (Assume that the latter are in fairly elliptical orbits; some of those retrograde.)
It's not critical that the killsats produce actual aerogel. A little cloud of snow, from a water tank and squirt nozzle, could also work. What matters is that it's cheap, reliable, low-mass, soft-ish, and collides head on-ish with Bit O'Junk - cutting the latter's orbital velocity by a few hundred meters per second. Done near apogee, that'd drop Mr. O'Junk's perigee enough for atmospheric drag to finish him off in very short order.
It's not critical that the killsats produce actual aerogel. A little cloud of snow, from a water tank and squirt nozzle, could also work. What matters is that it's cheap, reliable, low-mass, soft-ish, and collides head on-ish with Bit O'Junk - cutting the latter's orbital velocity by a few hundred meters per second. Done near apogee, that'd drop Mr. O'Junk's perigee enough for atmospheric drag to finish him off in very short order.
If you fragment the larger bits now you have a bunch of small bits that cross your orbit, are harder to track, and are still going very fast
no. like the proposal in the article above. a sandwich of thin light layers that fragment, plus much thicker layers of aerogel behind it to catch the tiny bits. All in one piece, so no bits flying off anywhere. Similar strategy to bullet proof vests actually (deform, then catch), but with a lot lighter of materials.
How do you keep it from tumbling out of control or into the station every time it takes a hit? All that energy has to go somewhere if you catch it.
Hm.. my impression was that most orbital debris was very very small, and the issue was more about making small holes with a lot of energy, than about knocking larger masses around.
In any case, if it's transferred enough energy to alter a trajectory, presumably maneuvering thrusters could fix it.
> the issue was more about making small holes with a lot of energy, than about knocking larger masses around
You’re not letting it pass through with an aerogel-backed whipple shield.
I wonder if you angled the whipple members you could preferentially deflect it at a high angle. That way it can carry most of its momentum away from the shield and the shielded station.
You’re not letting it pass through with an aerogel-backed whipple shield.
I wonder if you angled the whipple members you could preferentially deflect it at a high angle. That way it can carry most of its momentum away from the shield and the shielded station.
Unless it is a really large (KG plus) piece of debris - which such a shield wouldn’t be able to stop anyway - the actual net momentum transferred isn’t significant. It’s the point loading over such a short area and time due to the delta in velocities that causes the damage.
It’s also why being shot in a bullet proof vest with anything man portable doesn’t knock a person backwards (in real life), but gives them a heck of a bruise.
Without the vest, the bullet would go all the way through them, or create a huge wound cavity. [https://whitemountainforensic.com/wound-ballistics-motion-ef...]. Which is what causes the desired fatal effect.
Even when shot with something bigger (such as a tank round), there is no time for the momentum to transfer to their body without destroying it - for the same reason it is impossible to ‘throw’ an egg 20 yards by hitting it with a hammer.
These orbital debris are much much much faster than any known traditional bullets (17 km/s is 55,000 fps or 17x faster than the fastest common cartridge), so the effect is even more pronounced.
Interestingly, there was work by Newton that models these types of penetrations pretty well. They only start to apply to high speed bullet impacts around 3k+ FPS. The type of impact damage becomes noticably different then, with say 5.56/223 Remington on mild steel having an impact crater that looks remarkably like a asteroid impact crater at close range, but a normal ‘flat’ crater/dent at long range once the velocity has dropped significantly.
Once you past the speed of sound in the materials involved, it’s quite predictable based on the density of the material and the length of the projectile.
[https://en.m.wikipedia.org/wiki/Impact_depth]
It’s why modern tank penetrators are made of long, thin rods of high density material (such as depleted uranium or tungsten), and move very fast. They’ll penetrate essentially anything, with only depth varying based on density, because no material is able to transfer the force within itself effectively to ‘reject’ the penetration in time.
Spacing armor also helps, as it gives room for projectile fragments to break apart and lose energy over more area instead of efficiently transferring momentum directly into the point loaded part of the armor, which can dramatically reduce the impact depth in practice.
[https://en.m.wikipedia.org/wiki/Spaced_armour]
Angling the armor on the timescales involved in these impacts isn’t going to meaningfully deflect any penetrators though. It does, however, improve the effective depth of the armor. The forces involved in trying to redirect the later parts of the projectile based on the forces subjected to the first parts of the projectile don’t really work once you pass the speed of sound in the material.
[https://en.m.wikipedia.org/wiki/Sloped_armour]
Counter intuitive based on our normal life experience, but true.
So having many widely spaced layers of hard (to fragment the penetrator) then soft (to ‘catch’ fragments without transferring shock very well into later layers, hence spreading out the force over a wider area and often time) material in as ‘fluffy’ or an armor as possible is the most weight efficient way to stop very high speed projectiles - which is why it is used in space, because weight efficiency is really important.
Notably, heavier/denser versions of this (due to space constraints and the need to stop slower moving and heavier projectiles than in space) are widely used in newer generation main battle tanks in the form of chobham style composite armor. [https://en.m.wikipedia.org/wiki/Chobham_armour]
In those cases, sometimes adding explosives on top can help, as the penetration detonates it, and the resulting shockwave helps disrupt the projectile. [https://youtu.be/zK77-8kJ69c?si=PxMue9goABlfuiXY]
There are some neat videos of simulated tank armor penetrations on Youtube (look for “apfsds penetration test” for one example) that shows what is going on in pretty good fidelity.
So, to summarize - the aggregate force is not a real issue, it’s the damage done by the nature of the very high speed penetration. Think more ‘gamma radiation’, less ‘brick’.
It’s also why being shot in a bullet proof vest with anything man portable doesn’t knock a person backwards (in real life), but gives them a heck of a bruise.
Without the vest, the bullet would go all the way through them, or create a huge wound cavity. [https://whitemountainforensic.com/wound-ballistics-motion-ef...]. Which is what causes the desired fatal effect.
Even when shot with something bigger (such as a tank round), there is no time for the momentum to transfer to their body without destroying it - for the same reason it is impossible to ‘throw’ an egg 20 yards by hitting it with a hammer.
These orbital debris are much much much faster than any known traditional bullets (17 km/s is 55,000 fps or 17x faster than the fastest common cartridge), so the effect is even more pronounced.
Interestingly, there was work by Newton that models these types of penetrations pretty well. They only start to apply to high speed bullet impacts around 3k+ FPS. The type of impact damage becomes noticably different then, with say 5.56/223 Remington on mild steel having an impact crater that looks remarkably like a asteroid impact crater at close range, but a normal ‘flat’ crater/dent at long range once the velocity has dropped significantly.
Once you past the speed of sound in the materials involved, it’s quite predictable based on the density of the material and the length of the projectile.
[https://en.m.wikipedia.org/wiki/Impact_depth]
It’s why modern tank penetrators are made of long, thin rods of high density material (such as depleted uranium or tungsten), and move very fast. They’ll penetrate essentially anything, with only depth varying based on density, because no material is able to transfer the force within itself effectively to ‘reject’ the penetration in time.
Spacing armor also helps, as it gives room for projectile fragments to break apart and lose energy over more area instead of efficiently transferring momentum directly into the point loaded part of the armor, which can dramatically reduce the impact depth in practice.
[https://en.m.wikipedia.org/wiki/Spaced_armour]
Angling the armor on the timescales involved in these impacts isn’t going to meaningfully deflect any penetrators though. It does, however, improve the effective depth of the armor. The forces involved in trying to redirect the later parts of the projectile based on the forces subjected to the first parts of the projectile don’t really work once you pass the speed of sound in the material.
[https://en.m.wikipedia.org/wiki/Sloped_armour]
Counter intuitive based on our normal life experience, but true.
So having many widely spaced layers of hard (to fragment the penetrator) then soft (to ‘catch’ fragments without transferring shock very well into later layers, hence spreading out the force over a wider area and often time) material in as ‘fluffy’ or an armor as possible is the most weight efficient way to stop very high speed projectiles - which is why it is used in space, because weight efficiency is really important.
Notably, heavier/denser versions of this (due to space constraints and the need to stop slower moving and heavier projectiles than in space) are widely used in newer generation main battle tanks in the form of chobham style composite armor. [https://en.m.wikipedia.org/wiki/Chobham_armour]
In those cases, sometimes adding explosives on top can help, as the penetration detonates it, and the resulting shockwave helps disrupt the projectile. [https://youtu.be/zK77-8kJ69c?si=PxMue9goABlfuiXY]
There are some neat videos of simulated tank armor penetrations on Youtube (look for “apfsds penetration test” for one example) that shows what is going on in pretty good fidelity.
So, to summarize - the aggregate force is not a real issue, it’s the damage done by the nature of the very high speed penetration. Think more ‘gamma radiation’, less ‘brick’.
I was curious what the actual numbers were for momentum vs kinetic energy, and equivalents. A 1 gram projectile impacting at 17km/s imparts a force of 17kg m/s. [https://www.omnicalculator.com/physics/momentum]. That same
projectile has the kinetic energy of 144,500 joules (or in American, 106,577ft/lbs).
Average adult males mass between 60-80kg, so such an impact - if fully absorbed - would contribute the momentum equivalent to a light shove to an adult human. Approx. 1/3 of a meter per second, or in American, about a foot per second of velocity. Barely enough to make someone shuffle their feet to stay upright.
Energy wise, however, it is the equivalent of approximately 34 grams of TNT [https://en.m.wikipedia.org/wiki/TNT_equivalent], or 2x 20mm Anzio Anti Tank rounds [https://en.m.wikipedia.org/wiki/Anzio_20mm_rifle], or 8x 50BMG rounds [https://youtu.be/fUOh7a0cdUw?si=xX7Qzdl5ZfUUIVOs] - at the muzzle.
Those cartridges are roughly the size of a medium carrot. Absurdly large by sport shooting standards.
YouTube 50BMG video is a bit gruesome btw (ballistic dummy), but no actual blood.
The 50BMG is the most powerful ‘one man portable’ weapon you’re going to find, as they typically weigh over 20 lbs, and firing it is a rather intense experience. Especially since very aggressive muzzle brakes are necessary if the gun isn’t anchored to something.
Armor to protect against it is so heavy, it is pretty much impossible to wear in field operations. Think ‘bomb suit’. It will penetrate armor on many modern armored personnel carriers. 20mm is far more powerful, even without explosive shells.
And that is the size and velocity of the ‘small’ orbital debris.
Average adult males mass between 60-80kg, so such an impact - if fully absorbed - would contribute the momentum equivalent to a light shove to an adult human. Approx. 1/3 of a meter per second, or in American, about a foot per second of velocity. Barely enough to make someone shuffle their feet to stay upright.
Energy wise, however, it is the equivalent of approximately 34 grams of TNT [https://en.m.wikipedia.org/wiki/TNT_equivalent], or 2x 20mm Anzio Anti Tank rounds [https://en.m.wikipedia.org/wiki/Anzio_20mm_rifle], or 8x 50BMG rounds [https://youtu.be/fUOh7a0cdUw?si=xX7Qzdl5ZfUUIVOs] - at the muzzle.
Those cartridges are roughly the size of a medium carrot. Absurdly large by sport shooting standards.
YouTube 50BMG video is a bit gruesome btw (ballistic dummy), but no actual blood.
The 50BMG is the most powerful ‘one man portable’ weapon you’re going to find, as they typically weigh over 20 lbs, and firing it is a rather intense experience. Especially since very aggressive muzzle brakes are necessary if the gun isn’t anchored to something.
Armor to protect against it is so heavy, it is pretty much impossible to wear in field operations. Think ‘bomb suit’. It will penetrate armor on many modern armored personnel carriers. 20mm is far more powerful, even without explosive shells.
And that is the size and velocity of the ‘small’ orbital debris.
[deleted]
> a sacrificial shield well in front of the station along its orbital path
Whipple shield [1]. You’d want it as close to the station to save mass because that’s how spheres work.
[1] https://www.daviddarling.info/encyclopedia/W/Whipple_shield....
Whipple shield [1]. You’d want it as close to the station to save mass because that’s how spheres work.
[1] https://www.daviddarling.info/encyclopedia/W/Whipple_shield....
A large disc of lead or steel. With thrusters to position properly. Or multiple discs that spread out like flower petals.
Most current MRIs operate at around 1.5T, but this is also a measure of cost vs performance and results, not feasibility. Many will go up to 6T or so.
I believe some of the more research oriented MRIs can hit 10T+.
I believe some of the more research oriented MRIs can hit 10T+.
In a small area, Inside a tube the size of a large truck. Not facing outwards from a large space station …
Could it at least be a partial shield to help slow things down?
And maybe not directly on the station itself, but perhaps as a cloud of drone-ship defensive satellites to provide a defensive array around the space station -- almost like a fleet of smaller boats providing a perimeter around a larger aircraft carrier?
And maybe not directly on the station itself, but perhaps as a cloud of drone-ship defensive satellites to provide a defensive array around the space station -- almost like a fleet of smaller boats providing a perimeter around a larger aircraft carrier?
Well done, you created a cloud of debris to hit the ISS instead of just a single fragment.
Even if that's true, then wouldn't that mean that any impact is now distributed, and the severity of any individual impact is now mitigated?
If any kinetic energy can be divided and distributed amongst multiple projectiles (rather than a single point), then doesn't that lessen its severity?
If any kinetic energy can be divided and distributed amongst multiple projectiles (rather than a single point), then doesn't that lessen its severity?
With room temperature superconductors it would not only be possible but probably wouldn’t require any energy input to maintain the magnetic field.
That would be a STRONG magnetic field. Not a safe environment for people (think about living in the same room as an MRI magnet).
Also, not all satellite debris is metallic. Any ceramic / glass / plastic would zip right through.
Also, not all satellite debris is metallic. Any ceramic / glass / plastic would zip right through.
I would also wager that there is very little magnetic steel is used in the construction of spacecraft. Most grades of stainless steel, are not magnetic, and neither are aluminum and titanium are not magnetic. Very, very little carbon steel is used in modern commercial aircraft, and I would imagine an order of magnitude less would be used on a spacecraft.
Much more than room temperature is required. The exterior of the ISS gets up to 120 degrees C:
https://www.scienceabc.com/nature/universe/is-it-hot-or-cold...
https://www.scienceabc.com/nature/universe/is-it-hot-or-cold...
[deleted]
Sure, but if we're inventing things from science fiction we might as well avoid debris by phasing into the 4th dimension.
Recently some parts of a Crew Dragon landed in western North Carolina. The largest piece found so far is about the size of a car hood (~2.3 square meters) (insert joke about strange American measurement units here), and appears to mostly be carbon fiber.
https://www.space.com/nasa-confirms-debris-spacex-crew-drago...
Which sent me on a path to find out if carbon fiber is magnetic, and it appears to depend on the weave, the angle relative to the field, the strength of the field (naturally), and whether the magnetic field is static or alternating, and at what frequency.
https://ui.adsabs.harvard.edu/abs/2012JAP...112k3921G/abstra...
https://www.space.com/nasa-confirms-debris-spacex-crew-drago...
Which sent me on a path to find out if carbon fiber is magnetic, and it appears to depend on the weave, the angle relative to the field, the strength of the field (naturally), and whether the magnetic field is static or alternating, and at what frequency.
https://ui.adsabs.harvard.edu/abs/2012JAP...112k3921G/abstra...
A magnetic shield would not keep away non-conductive objects.
That's what the 30mm point defense cannon is for.
How does the recoil work out?
the same way they ever make ballistic weapons in space work in fiction, an aim-able exhaust port and accompanying verniers.
or, for bonus points during an extra busy war, symmetrical cannons firing synchronized volleys.
or, for bonus points during an extra busy war, symmetrical cannons firing synchronized volleys.
If you paint them with an electron beam, the magnetic shield will deflect them marvelously
At the energies needed to power a magnetic shield, and the precision needed to tag hipersonic debris with an electron beam, why not vaporize/deflect them with lasers instead?
Vaporising doesn’t help (the mass hasn’t changed and neither has the velocity).
Deflection by vaporising a very small part of the object can work, if you can spot it coming and hit it in time.
Assuming you can somehow detect a 1cm piece 1km away, you have approximately 10ms to accurately apply enough power to deflect it.
Deflection by vaporising a very small part of the object can work, if you can spot it coming and hit it in time.
Assuming you can somehow detect a 1cm piece 1km away, you have approximately 10ms to accurately apply enough power to deflect it.
I recently learned about this company that is designing a satellite to remove debris from space: https://www.starfishspace.com/
"Shortly after 9 p.m. EDT, @NASA instructed crews aboard the space station to shelter in their respective spacecraft as a standard precautionary measure after it was informed of a satellite break-up at an altitude near the station’s earlier Wednesday. Mission Control continued to monitor the path of the debris, and after about an hour, the crew was cleared to exit their spacecraft and the station resumed normal operations."
What makes the one spacecraft safer than the other?
Its not so much that as it is their escape pod if the station has a catastrophic failure.
The specific answer to OP’s question is manoeuvring thrusters, a heat shield and a landing system.
The ability to evacuate in it.
They could emergency return to earth right away if needed.
the assigned crew has been trained to operate it.
the logistics [crew mass, crew capabilities] have been factored into S.O.P. of the mission.
the logistics [crew mass, crew capabilities] have been factored into S.O.P. of the mission.
Smaller.
[deleted]
Thickness of the walls.
starting to see symptoms of something that could lead to Kessler Syndrome
At that altitude? I don't know. This debris should clear out in a few years, right?
Yes.
"At around 400 kilometers and into the 500-km realm — home to ISS and the SpaceX Starlink satellites among others — atmospheric drag plays a major role. Dead satellites and debris usually slow and burn up in the atmosphere in just a few years. This natural cleansing process accelerates when the sun becomes more active and solar coronal mass ejections strike Earth and cause the atmosphere to swell."
https://aerospaceamerica.aiaa.org/features/understanding-the...
Still, if the events occur not once in a decade but multiple times a year that could mean trouble for space travel:
"Linares sees a potential future where 'humans probably don’t have any incentive to launch satellites, because we’re losing 50% of them' to collisions with debris, he says."
"At around 400 kilometers and into the 500-km realm — home to ISS and the SpaceX Starlink satellites among others — atmospheric drag plays a major role. Dead satellites and debris usually slow and burn up in the atmosphere in just a few years. This natural cleansing process accelerates when the sun becomes more active and solar coronal mass ejections strike Earth and cause the atmosphere to swell."
https://aerospaceamerica.aiaa.org/features/understanding-the...
Still, if the events occur not once in a decade but multiple times a year that could mean trouble for space travel:
"Linares sees a potential future where 'humans probably don’t have any incentive to launch satellites, because we’re losing 50% of them' to collisions with debris, he says."
At 350km a lot will live less than a year
Maybe twenty years, after taking out the Starlink constellation and most other satellites below ~400 KM.
I'm sure that we'd still risk unmanned launches to higher altitudes during this time, but manned launches would very likely be restricted, at least by risk-adverse NASA.
I'm sure that we'd still risk unmanned launches to higher altitudes during this time, but manned launches would very likely be restricted, at least by risk-adverse NASA.
A starlink satellite has a life expectancy of only about 5 years anyway, and that is WITH station keeping ion thrusters. Anything smaller than a starlink satellite will likely have an even shorter lifespan due to having worse mass vs surface area ratio because of the square cube law, and should be gone within a few years. Anything larger can easily be tracked with radars etc and should still be gone relatively quickly.
Yes, but we won't have use of the functionality that the Starlink satellites provide for the duration of the natural deorbits from ~400 KM.
Smaller debris deorbits faster, Starlink is in VLEO.
Yes, but the ISS debris would be raining down on it from about ~400 KM - so it will take a bit longer for all that to come down.
There would need to be a lot of it to overcome continued launches. Once each piece of debris is coming down to that altitude it doesn't have a lot of time left.
How can you possibly tell that from something that happens regularly anyway?
"One bacterium is put in a bottle at 11:00 a.m. and it is observed that the bottle is full of bacteria at 12:00 noon. Here is a simple example of exponential growth in a finite environment. This is mathematically identical to the case of the exponentially growing consumption of our finite resources of fossil fuels.
11:58 a.m. -> Bottle is one quarter full.
11:59 a.m. -> Bottle half-full !
12:00 noon -> Bottle is full !
https://www.albartlett.org/articles/art_forgotten_fundamenta....
11:58 a.m. -> Bottle is one quarter full.
11:59 a.m. -> Bottle half-full !
12:00 noon -> Bottle is full !
https://www.albartlett.org/articles/art_forgotten_fundamenta....
That shows such a poor understanding of exponential growth that it makes me think this person should not be teaching physics.
First of all, exponential growth basically doesn't ever actually occur in nature: everything has a carrying capacity. Sometimes the carrying capacity is so high it doesn't matter, but clearly in the case of the bottle it does. The growth will slow down significantly as the bacteria approaches the capacity of the bottle. The bottle could easily be half full as early as 11:30 as the available food for the bacteria starts becoming scarce enough to limit its growth.
Secondly, 2^60 bacteria would weigh about 1,100 kg. Assuming the bottle is 1L (larger than a standard wine bottle), you'd need over 1000 bottles to house that much bacteria. So no, if it doubles every minute, then the bottle has been full for the last 10 minutes.
I'm being generous and assuming some process is keeping the flask continuously well-mixed, otherwise you don't even have exponential growth in the ideal case (it's limited by the expanding surface area of the colony).
You might think I'm being pedantic, but the entire exercise is to put some "real world" context to blow the minds of people and illustrate how exponential growth "really" works. But that's not how exponential growth really works in the real world, at all. Instead it's just taking a model of spherical cows to an absurd conclusion that only serves to further confuse people's understanding of the world. It's like those awful anti-intuition-pumps (intuition sinks?) about stretching all your DNA from end-to-end.
First of all, exponential growth basically doesn't ever actually occur in nature: everything has a carrying capacity. Sometimes the carrying capacity is so high it doesn't matter, but clearly in the case of the bottle it does. The growth will slow down significantly as the bacteria approaches the capacity of the bottle. The bottle could easily be half full as early as 11:30 as the available food for the bacteria starts becoming scarce enough to limit its growth.
Secondly, 2^60 bacteria would weigh about 1,100 kg. Assuming the bottle is 1L (larger than a standard wine bottle), you'd need over 1000 bottles to house that much bacteria. So no, if it doubles every minute, then the bottle has been full for the last 10 minutes.
I'm being generous and assuming some process is keeping the flask continuously well-mixed, otherwise you don't even have exponential growth in the ideal case (it's limited by the expanding surface area of the colony).
You might think I'm being pedantic, but the entire exercise is to put some "real world" context to blow the minds of people and illustrate how exponential growth "really" works. But that's not how exponential growth really works in the real world, at all. Instead it's just taking a model of spherical cows to an absurd conclusion that only serves to further confuse people's understanding of the world. It's like those awful anti-intuition-pumps (intuition sinks?) about stretching all your DNA from end-to-end.
The number line doesn’t have a carrying capacity!
And at 12:01 there's two bottles of bacteria!
This does not answer my question, unless you also have proof that the amount of cases of the ISS crew having to take shelter is also increasing exponentially. Since the astronauts went back to work after 1 hour instead of moving back to Earth, we can infer that the perceived danger has passed.
(That is quite beside the point that Kessler syndrome at that altitude is definitely not the type of "exponential growth in a finite environment" that the linked article describes, because orbital decay means that the smaller the particles get, the faster they will deorbit themselves)
(That is quite beside the point that Kessler syndrome at that altitude is definitely not the type of "exponential growth in a finite environment" that the linked article describes, because orbital decay means that the smaller the particles get, the faster they will deorbit themselves)
At 11:59 I see it more as half empty.
> The incident illustrates what NASA officials have been emphasizing about the Boeing Starliner spacecraft, which is more than three weeks into what was expected to be a 10-day Crew Flight Test mission. Starliner is on a test mission with two astronauts and is authorized to leave the ISS in case of emergency. (The other two crewed spacecraft docked to the ISS are a SpaceX Dragon carrying four astronauts, and a Russian Soyuz with three people on board.)
>what NASA officials have been emphasizing
Anyone understand specifically what this is referring to? I read it several times and I don't see a hint. Normally this phrase would be followed by an explanation like
>this illustrates what Alice has been emphasizing -- that Bob has excellent OpSec
Anyone understand specifically what this is referring to? I read it several times and I don't see a hint. Normally this phrase would be followed by an explanation like
>this illustrates what Alice has been emphasizing -- that Bob has excellent OpSec
The Boeing Starliner craft has had multiple issues (IIRC 5 separate thrusters not working and at least 2 separate helium leaks) since docking with the ISS. NASA continues to stress that Starliner is authorized to return astronauts to earth in the event of an emergency. NASA, at the same time, delayed the return of said Starliner indefinitely until they can analyze more test data.
https://arstechnica.com/space/2024/06/nasa-indefinitely-dela...
https://arstechnica.com/space/2024/06/nasa-indefinitely-dela...
I don’t see what that has to do with this story, though. Starliner’s issues have nothing to do with the breakup of a satellite nor do the issues affect Starliner’s usage as a shelter.
This article and headline just reek of the author grasping at straws to try and shoehorn Starliner into this story. The headline could’ve easily said “shelter in Soyuz” and nothing would’ve changed about the actual story at hand.
This article and headline just reek of the author grasping at straws to try and shoehorn Starliner into this story. The headline could’ve easily said “shelter in Soyuz” and nothing would’ve changed about the actual story at hand.
> I don’t see what that has to do with this story, though.
It is noteworthy because the safety/reliability of the Starliner was called into question. The fact that the two Starliner astronauts are still on the ISS means that NASA does not entirely trust the spacecraft. The fact that they sent them to shelter in it is noteworthy because it means that they trust it enough to be used in an emergency. If they would have asked Butch and Suni to shelter instead in the dragon or the soyuz that would have been a serious egg on the face of Boeing.
> nor do the issues affect Starliner’s usage as a shelter
Okay. I think i understand what you might be thinking. Please correct me if I am wrong. It sounds like you think the shelter functions because it is thick and that shields the astronauts. If you have that mental model that would explain why you think that the issues with Starliner does not affect its usage as a shelter. After all the problems with the trusters does not change the spacecraft’s wall thickness.
But this is not the correct mental model. The spacecraft is not sheltering them with its thickness. If they get unlucky orbital debris will cut through Starliner like a hot knife through butter. The real reason they shelter in the spacecraft is that they can use it to land if the station gets hit and they have to abandon it. So the correct mental model is that of a rescue boat, not a debris shield.
And if you are thinking that way it is easy to see how the trusters being less than perfectly reliable hampers the usage of the spacecraft as a shelter (as a rescue boat). It just happens to be that the relative danger posed by the truster problems is smaller (in NASA’s estimate) than the relative danger posed by trying to ride the other spacecrafts down without a seat for the extra astronauts.
It is noteworthy because the safety/reliability of the Starliner was called into question. The fact that the two Starliner astronauts are still on the ISS means that NASA does not entirely trust the spacecraft. The fact that they sent them to shelter in it is noteworthy because it means that they trust it enough to be used in an emergency. If they would have asked Butch and Suni to shelter instead in the dragon or the soyuz that would have been a serious egg on the face of Boeing.
> nor do the issues affect Starliner’s usage as a shelter
Okay. I think i understand what you might be thinking. Please correct me if I am wrong. It sounds like you think the shelter functions because it is thick and that shields the astronauts. If you have that mental model that would explain why you think that the issues with Starliner does not affect its usage as a shelter. After all the problems with the trusters does not change the spacecraft’s wall thickness.
But this is not the correct mental model. The spacecraft is not sheltering them with its thickness. If they get unlucky orbital debris will cut through Starliner like a hot knife through butter. The real reason they shelter in the spacecraft is that they can use it to land if the station gets hit and they have to abandon it. So the correct mental model is that of a rescue boat, not a debris shield.
And if you are thinking that way it is easy to see how the trusters being less than perfectly reliable hampers the usage of the spacecraft as a shelter (as a rescue boat). It just happens to be that the relative danger posed by the truster problems is smaller (in NASA’s estimate) than the relative danger posed by trying to ride the other spacecrafts down without a seat for the extra astronauts.
No, that isn’t the case at all. The issues with Starliner do not affect its ability to return to earth or function as an “escape pod” if that were necessary. There’s no safety issue or concern at all with using Starliner as a return craft. The issues with Starliner, as has been mentioned many times over the last few weeks, are to do with other parts of Starliner that don’t affect its return (it’s literally the thrusters that aren’t even part of Starliner that _will_ return).
I’m guessing that the fact they are still up at the ISS when they should have returned to Earth at this point.
They are there by choice. The parts of Starliner used in deorbiting are all functional. But the parts that leaked will get discarded and burn up themselves in the atmosphere, which prevents examining them. So the astronauts are hanging around to do that examination while they can.
NASA and Boeing have been battling criticism, fair or unfair you can decide, over how Boeing spent a lot more money and time and sent Starliner to the ISS with a bunch of engine failures and leaks.
So the author went for an awkward attempt at saying "Look how great Starliner is, astronauts are even sheltering in it from all that Russian debris and will fly it back if needed".
> this illustrates what Alice has been emphasizing -- that Bob has excellent OpSec
The answer is below a bit:
> "Starliner [...] is authorized to leave the ISS in case of emergency"
I guess it would be something like:
"As we all know, Bob has had a few slip-ups recently: he leaked his admin credentials in a public github repo, and then he also asked for a salary increase, but we'd like to emphasize that in an emergency Bob is fully authorized to respond to incidents and operate the system"
So the author went for an awkward attempt at saying "Look how great Starliner is, astronauts are even sheltering in it from all that Russian debris and will fly it back if needed".
> this illustrates what Alice has been emphasizing -- that Bob has excellent OpSec
The answer is below a bit:
> "Starliner [...] is authorized to leave the ISS in case of emergency"
I guess it would be something like:
"As we all know, Bob has had a few slip-ups recently: he leaked his admin credentials in a public github repo, and then he also asked for a salary increase, but we'd like to emphasize that in an emergency Bob is fully authorized to respond to incidents and operate the system"
[deleted]
According to both US Space Command and LEO Labs, the satellite in question was a 6-ton non-functional Russian satellite known as "RESURS-P1": https://en.wikipedia.org/wiki/Resurs-P_No.1
https://twitter.com/LeoLabs_Space/status/1806140666222948679
https://www.spacecom.mil/Newsroom/News/Article-Display/Artic...
https://twitter.com/LeoLabs_Space/status/1806140666222948679
https://www.spacecom.mil/Newsroom/News/Article-Display/Artic...
According to astrophysist and space historian Jonathan McDowell, Resurs-P1 passed over Plesetsk, a test launch base for the Russian Nudol anti-satellite system around the time of its debirs-generating event.
Note that his tweets indicate that he does not believe it to be an ASAT test.
https://x.com/planet4589/status/1806333953617334688
https://x.com/planet4589/status/1806333953617334688
"Another comment on Resurs-P1; the sat is 5600 kg. That's huge. It would be crazy and very bad of the Russians to use such a massive sat as an antisatellite target. Now it may be true that the Russian govt is indeed crazy and v. bad, but still, am leaning towards 'not ASAT'."
is the whole tweet.
If Putin were doing something stupid because he can, that would sound pretty in keeping to me.
is the whole tweet.
If Putin were doing something stupid because he can, that would sound pretty in keeping to me.
They wouldn’t just be endangering American astronauts with a belligerent ASAT test.
Putin does nothing in space. Its Roscosmos and its executives. It would be silly if someone said that Biden destroyed a satellite in space right? Putin isnt really experienced in space programs. Other people are.
An ASAT test would be authorised at the highest levels of government.
It would not be silly to say it.
It would not be silly to say it.
IIRC Putin's First deputy prime minister is also the deputy PM for space, the director of Roscosmos being directly beneath him. Maybe Putin isn't a megalomaniac.
Why do you imply Roscosmos is an autonomous organisation not under direct control of the President? Who do you say is in charge of decisions to take military actions (fire weapons) into international regions (space) from Russia?
Why do you imply Roscosmos is an autonomous organisation not under direct control of the President? Who do you say is in charge of decisions to take military actions (fire weapons) into international regions (space) from Russia?
How often do satellites break up into clouds of orbiting debris?
Or another angle -- what percentage of satellite EOL events is "breaking up into a debris field" (vs "burning up in the atmosphere")?
Or another angle -- what percentage of satellite EOL events is "breaking up into a debris field" (vs "burning up in the atmosphere")?
More often than I would have expected:
> Space debris (also known as space junk, space pollution, space waste, space trash, space garbage, or cosmic debris) are defunct human-made objects in space – principally in Earth orbit – which no longer serve a useful function. These include derelict spacecraft (nonfunctional spacecraft and abandoned launch vehicle stages), mission-related debris, and particularly-numerous in-Earth orbit, fragmentation debris from the breakup of derelict rocket bodies and spacecraft.
https://en.wikipedia.org/wiki/Space_debris
> There were 190 known satellite breakups between 1961 and 2006. By 2015, the total had grown to 250 on-orbit fragmentation events.
https://en.wikipedia.org/wiki/List_of_space_debris_producing...
> Space debris (also known as space junk, space pollution, space waste, space trash, space garbage, or cosmic debris) are defunct human-made objects in space – principally in Earth orbit – which no longer serve a useful function. These include derelict spacecraft (nonfunctional spacecraft and abandoned launch vehicle stages), mission-related debris, and particularly-numerous in-Earth orbit, fragmentation debris from the breakup of derelict rocket bodies and spacecraft.
https://en.wikipedia.org/wiki/Space_debris
> There were 190 known satellite breakups between 1961 and 2006. By 2015, the total had grown to 250 on-orbit fragmentation events.
https://en.wikipedia.org/wiki/List_of_space_debris_producing...
Makes me wonder what is the half-life of space debris.
> The higher the altitude, the longer the orbital debris will typically remain in Earth orbit. Debris left in orbits below 600 km normally fall back to Earth within several years. At altitudes of 800 km, the time for orbital decay is often measured in centuries. Above 1,000 km, orbital debris will normally continue circling the Earth for a thousand years or more.
https://orbitaldebris.jsc.nasa.gov/faq/
https://orbitaldebris.jsc.nasa.gov/faq/
Struck by other smaller but high energy debris, faulty batteries that are still receiving charge from unshunted solar arrays, similar mechanical failures from attitude control systems, unused propellant leaks or ruptures. There are a lot of things that can go wrong which is why we have the 25 year rule now.
[deleted]
and of those how many do it on the hour "at approximately 1000 MT (1600 UTC)"?
Leolabs says the fragmentation occurred between 13:05 UTC 26 June and 00:51 UTC 27 June.
https://x.com/LeoLabs_Space/status/1806140666222948679
https://x.com/LeoLabs_Space/status/1806140666222948679
Orbital dynamics would say that makes it less likely to be an asat test if it was over the launch site.
asat missiles go close to straight up then get whacked by the passing satellite- not like a typical orbital launch
"This happened, for example, after Russia deliberately destroyed a satellite in November 2021 as part of a surprise anti-satellite test that other countries (including the United States) condemned".
Funny they singled out Russia. From Wikipedia:
"...a few countries (China, India, Russia, and the United States) have successfully shot down their own satellites to demonstrate their ASAT capabilities in a show of force."
Funny they singled out Russia. From Wikipedia:
"...a few countries (China, India, Russia, and the United States) have successfully shot down their own satellites to demonstrate their ASAT capabilities in a show of force."
It depends on the orbit of the targeted satellite. If all debris are going to be at low altitude, reentering quickly and not crossing busy orbits, it’s fine. If debris are going to cross highly congested orbits often and for a long time, it’s bad. IIRC the Russian test was pretty bad in that regard
China shot a satellite from the ground.[1] Sometime after the US destroyed a satellite from a Navy ship [2].
Before these times the US did it from an F-15.[3]
[1]https://en.m.wikipedia.org/wiki/2007_Chinese_anti-satellite_...
[2]https://en.m.wikipedia.org/wiki/Operation_Burnt_Frost#:~:tex....
[3]https://en.m.wikipedia.org/w/index.php?title=Solwind&diffonl...
Before these times the US did it from an F-15.[3]
[1]https://en.m.wikipedia.org/wiki/2007_Chinese_anti-satellite_...
[2]https://en.m.wikipedia.org/wiki/Operation_Burnt_Frost#:~:tex....
[3]https://en.m.wikipedia.org/w/index.php?title=Solwind&diffonl...
That ASM-135 is probably the coolest thing I've read about all week
It was a Russian satellite that broke up as it passed over Russian territory.
Specifically, the bit that might be the launch site for anti-satellite weaponry.
the "for example" is the bit in the first quoted sentence to make it weird. if the debris is directly from the most recent Russian "test", then it would be right to call it out.
The word "surprise" might have relevance.
Other countries generally try to limit potential impact on other high-value objects that might be affected by such tests, Russians don't care.
From only 9 days ago from HN:
'The missunderstood Kessler Syndrome' https://news.ycombinator.com/item?id=40716235
'The missunderstood Kessler Syndrome' https://news.ycombinator.com/item?id=40716235
As the cost of mass to orbit lowers by orders of magnitude in, likely, the next decade, we can begin seeing spacecraft that are far more durable, redundant and agile. They will have ample propellant to move out of the way and they will have life support systems and failure modes designed to withstand and allow for the repair of small impacts.