JPL's Plan for the Next Mars Helicopter(spectrum.ieee.org)
spectrum.ieee.org
JPL's Plan for the Next Mars Helicopter
https://spectrum.ieee.org/the-next-mars-helicopter
112 comments
For me, the value of ingenuity has not been the fact that it flies but rather that is designed to be operated in a far more risky way than a traditional rover. A mission that consisted solely of a single larger helicopter would be far more risk averse. It would travel shorter distances, move slower and have so much redundancy built in that there is likely to be little mass dedicated to the scientific instruments.
I think one of the most interesting parts of Ingenuity is that it uses off the shelf ARM processors instead of highly specialized (and old) radiation-hardened processors.
> ...ARM processors instead of highly specialized...
You've got that backwards:
Perseverance is equipped with a RAD750, which is simply a radiation hardened PowerPC 750 - that is about as general purpose as it gets.
Ingenuity is equipped with a Snapdragon 801, which is an unhardened Qualcomm processor tailor made for cellphones. I doubt anyone could know the degree to which it is "highly specialized" for cellphones without first signing NDAs from multiple parties.
I've always found the most impressive aspect of these programs to be the careful engineering that extends the mission life far beyond the original goals. Ingenuity was engineered to die - on either a cliff face or from radiation poisoning, which isn't interesting - it is wasteful.
You've got that backwards:
Perseverance is equipped with a RAD750, which is simply a radiation hardened PowerPC 750 - that is about as general purpose as it gets.
Ingenuity is equipped with a Snapdragon 801, which is an unhardened Qualcomm processor tailor made for cellphones. I doubt anyone could know the degree to which it is "highly specialized" for cellphones without first signing NDAs from multiple parties.
I've always found the most impressive aspect of these programs to be the careful engineering that extends the mission life far beyond the original goals. Ingenuity was engineered to die - on either a cliff face or from radiation poisoning, which isn't interesting - it is wasteful.
There are billions of ARM processors used in a wide range of applications. How many radiation hardened CPUs are in use today?
And the one of the goals of Ingenuity was to see if a COTS processor could be used on Mars. The fact that it's survived this long is really encouraging.
And the one of the goals of Ingenuity was to see if a COTS processor could be used on Mars. The fact that it's survived this long is really encouraging.
> How many radiation hardened CPUs are in use today?
Whoosh. A radiation hardened PowerPC 750 operates no differently from a PowerPC 750 you'd find on Ebay. You are effectively saying "Yeah, but how many commercial temperature range processors are in use today?!" It is weird, because it is such a silly distinction to point to that you have to actually examine the manufacturer's packaging datasheet to spot the difference. But at the same time you have no problem conflating every processor using IP licensed by Arm Ltd as the same thing... they have at least 20 distinct architectures and it doesn't look like compatibility was ever much of a priority. The larger point being that the powerpc ISA is infinitely more coherent than the fractured mess Arm has going on, which is very likely the product of designers aligning the platform with disposable electronics. Do you really want to see that trend go beyond crappy cellphones designed to be thrown out every other year?
> ...one of the goals of Ingenuity was to see if a COTS processor could be used on Mars.
That has been said - but has never been explained why... because it is such a thoroughly covered concern that has had a huge amount of money spent on developing industry standards and commissioning incredibly comprehensive studies. So this justification is either an oversimplification to the point of being lie, or it is an indictment on their own work (and that of many others) with regard to the effects of radiation on electronic. Does Mars have some new kind of radiation that our highly controlled labs can't replicate? Of course not, it is a nonsensically wasteful way to test our understanding of radiation - at best.
> The fact that it's survived this long is really encouraging.
lol, the processor has no way of self diagnosing internal faults caused by ionizing radiation. That would be like celebrating your lack of cancer while on a smoke break at your job in an asbestos factory - and at the same time bragging about never getting medical checkups.
Whoosh. A radiation hardened PowerPC 750 operates no differently from a PowerPC 750 you'd find on Ebay. You are effectively saying "Yeah, but how many commercial temperature range processors are in use today?!" It is weird, because it is such a silly distinction to point to that you have to actually examine the manufacturer's packaging datasheet to spot the difference. But at the same time you have no problem conflating every processor using IP licensed by Arm Ltd as the same thing... they have at least 20 distinct architectures and it doesn't look like compatibility was ever much of a priority. The larger point being that the powerpc ISA is infinitely more coherent than the fractured mess Arm has going on, which is very likely the product of designers aligning the platform with disposable electronics. Do you really want to see that trend go beyond crappy cellphones designed to be thrown out every other year?
> ...one of the goals of Ingenuity was to see if a COTS processor could be used on Mars.
That has been said - but has never been explained why... because it is such a thoroughly covered concern that has had a huge amount of money spent on developing industry standards and commissioning incredibly comprehensive studies. So this justification is either an oversimplification to the point of being lie, or it is an indictment on their own work (and that of many others) with regard to the effects of radiation on electronic. Does Mars have some new kind of radiation that our highly controlled labs can't replicate? Of course not, it is a nonsensically wasteful way to test our understanding of radiation - at best.
> The fact that it's survived this long is really encouraging.
lol, the processor has no way of self diagnosing internal faults caused by ionizing radiation. That would be like celebrating your lack of cancer while on a smoke break at your job in an asbestos factory - and at the same time bragging about never getting medical checkups.
>A radiation hardened PowerPC 750 operates no differently from a PowerPC 750 you'd find on Ebay.
The RAD750 costs $200k. I doubt the ARM processor in Ingenuity costs that much.
>Do you really want to see that trend go beyond crappy cellphones designed to be thrown out every other year?
I want cheaper rovers and probes, this is NASA's test for viability
>with regard to the effects of radiation on electronic.
You can test shit in the lab all day but eventually you have to test in the field.
>Does Mars have some new kind of radiation that our highly controlled labs can't replicate?
Do we know exactly the levels of radiation on the surface?
>Of course not, it is a nonsensically wasteful way to test our understanding of radiation - at best.
It's a live, in the field test of off-the-shelf components in space craft on a bonus mission unrelated to the main rover. What would be a sensically nonwasteful test of COSTS processors on Mars be?
>the processor has no way of self diagnosing internal faults caused by ionizing radiation
The helicopter flies and takes pictures. It's had 12 flights as of this comment. When it stops working, we'll know how long regular processors can last.
The RAD750 costs $200k. I doubt the ARM processor in Ingenuity costs that much.
>Do you really want to see that trend go beyond crappy cellphones designed to be thrown out every other year?
I want cheaper rovers and probes, this is NASA's test for viability
>with regard to the effects of radiation on electronic.
You can test shit in the lab all day but eventually you have to test in the field.
>Does Mars have some new kind of radiation that our highly controlled labs can't replicate?
Do we know exactly the levels of radiation on the surface?
>Of course not, it is a nonsensically wasteful way to test our understanding of radiation - at best.
It's a live, in the field test of off-the-shelf components in space craft on a bonus mission unrelated to the main rover. What would be a sensically nonwasteful test of COSTS processors on Mars be?
>the processor has no way of self diagnosing internal faults caused by ionizing radiation
The helicopter flies and takes pictures. It's had 12 flights as of this comment. When it stops working, we'll know how long regular processors can last.
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The issue is it has to be pretty big to carry much in the way of scientific instruments to begin with. Right now there's no scientific instruments on Ingenuity beyond the camera and that is only really useful for surveying the ground. Also Ingenuity can be risky because it's goal is to test the craft itself so they take risks with it to see how well the design performs at the edges of it's flight envelope.
The most likely way for MSH to get funded in the near term is as part of NASA's sample return goals. 5kg of science payload is not insubstantial, but even if MSH's primary instrument was just a sampling tool, it could still do some unique stuff. It could collect otherwise inaccessible samples from across a very wide area, and then bring them all back to a centralized location, which a rover can't do very well.
> Aerial mobility gives you reach, range, and resolution
Sounds like the 1st Cav in Vietnam - cower, you tentacled Martian fiends!
Sounds like the 1st Cav in Vietnam - cower, you tentacled Martian fiends!
Wonder if it is practical to design Helicopter with nuclear battery similar to the rover....
Much too much mass. The atmosphere on Mars is 6.518 millibars. Look to the structure and mass of terrestrial birds for a guide.
terrestrial birds which would all have far too low of a lift to weight ratio on mars to ever have any hope of flying. The current mars helicopter is pretty incredible
Yes, to be pedantic about it, but I didn't say "send birds" or "do exactly what birds do", I said to look to them for ideas. Eliminate every extra gram, optimize aerodynamics and control for the purpose (c.f. owls vs. quail vs. hummingbird vs. woodpeckers) and go from there. Don't try to build a flying machine around power source that is essentially a hunk of dense metal.
just pointing out that you'd have to go to much further lengths than birds on earth have gone
No, you're just missing the point of my argument with and arguing pedantics by insisting on a literal reading what I said.
Plutonium is really heavy, if you were to do that it strikes me that you'd be better off having some kind of wireless charging device which the helicopter lands on (But at that point why not solar power).
You'd probably already need some batteries anyway as I'm guessing that the transient spikes in power usage would probably exceed any RTG you could fit in a helicopter anyway.
You'd probably already need some batteries anyway as I'm guessing that the transient spikes in power usage would probably exceed any RTG you could fit in a helicopter anyway.
Probably you would use strontium-90, instead, if weight was important. Strontium is 7.5 times less dense than plutonium.
Strontium-90 produces 0.95W/g, where Pu-238 produces only 0.57 W/g. So, it takes only 3/5 as much, by weight, to produce the same heat as a Pu-238 RTG, although it takes 4.5x as much room. Room is relatively cheap on spacecraft, vs. mass.
This makes me wonder why they use Pu-238 RTGs in spacecraft at all. Maybe because it lasts a bit longer?
Strontium-90 produces 0.95W/g, where Pu-238 produces only 0.57 W/g. So, it takes only 3/5 as much, by weight, to produce the same heat as a Pu-238 RTG, although it takes 4.5x as much room. Room is relatively cheap on spacecraft, vs. mass.
This makes me wonder why they use Pu-238 RTGs in spacecraft at all. Maybe because it lasts a bit longer?
... Probably just because of the industrial process availability of plutonium, as spinoff from weapons work. Sr-90 has no local infrastructure. Which is just dumb.
A radioisotope thermoelectric or betavoltaic generator would probably be too heavy for a helicopter, so you'd probably need something a lot more intense than simple radioactive decay.
Do you see any nuclear-powered aircraft flying around on Earth?
You can't buy aviation fuel on Mars, though.
Earth also doesn't have any nuclear powered rovers driving on the surface and yet Mars does. Might have something to do with the fact that the risk to humans on Mars is slightly lower than on Earth,no?
Yes, but also that you can't refill with gas on Mars. And of course we do have nuclear powered vehicles cruising around on Earth. We have also had nuclear powered bombers and cruise missiles, none of which were exactly successful, but not even the US DoD has ever suggested a nuclear powered helicopter. It would be a great introduction to our relationship with Mars if one of the first things we ever did was to spill plutonium across its surface when the helo crashed (as it would, eventually).
Not that likely even in the event of a crash.
https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...
"This incident resulted in the NASA Safety Committee requiring intact reentry in future RTG launches, which in turn impacted the design of RTGs in the pipeline."
https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...
"This incident resulted in the NASA Safety Committee requiring intact reentry in future RTG launches, which in turn impacted the design of RTGs in the pipeline."
French EVs are over 70% nuclear powered. We just keep the nuclear generators stationary and use battery buffers in the car to save weight.
You might argue it's about risk, but that didn't seem like such a huge deal when we tried to make nuclear cars and planes back in the 50s. RTGs are just incredibly inefficient, and properly shielded fission reactors are incredibly heavy.
You might argue it's about risk, but that didn't seem like such a huge deal when we tried to make nuclear cars and planes back in the 50s. RTGs are just incredibly inefficient, and properly shielded fission reactors are incredibly heavy.
Yeah, the 1950s involved serious consideration of some truly horrific nuclear flight concepts, so I wouldn't be so dismissive of risk as a factor. Not like airliner crashes are awesome, but they don't drop a reactor core on whatever they crash into. Not to mention proliferation concerns, operator staffing requirements, security staffing requirements. There's very straightforward reasons nuclear powered flight on earth never went past the earliest exploration of a couple prototypes. Russia is working on a nuclear powered cruise missile and has already had one serious mishap with it.
We also don't see any nuclear-powered rovers driving around Earth, so I don't think this is a helpful way to make a point.
No, because it's easy to refuel here on earth and there's no easy way to refuel a helicopter on Mars.
If we didn't have oxygen and oil, we probably would.
We developed them during the Cold War. The issue was the massive release of radiation behind them. Don't fly it over your own country. But they can cruise for days!
That'd be difficult in Mars' atmosphere -- but the planned *Titan* helicopter will actually be RTG powered:
https://en.wikipedia.org/wiki/Dragonfly_(spacecraft)#Design_...
https://news.ycombinator.com/item?id=18947350 ("NASA May Decide This Year to Land a Drone on Saturn's Moon Titan")
https://news.ycombinator.com/item?id=20337042 ("A technical look at the Dragonfly Titan mission")
>"Flight on Titan is aerodynamically benign as Titan has low gravity and little wind, and its dense atmosphere allows for efficient rotor propulsion.[35] The radioisotope thermoelectric generator (RTG) power source has been proven in multiple spacecraft, and the extensive use of quad drones on Earth provides a well-understood flight system that is being complemented with algorithms to enable independent actions in real-time.[35]"
https://en.wikipedia.org/wiki/Dragonfly_(spacecraft)#Design_...
https://news.ycombinator.com/item?id=18947350 ("NASA May Decide This Year to Land a Drone on Saturn's Moon Titan")
https://news.ycombinator.com/item?id=20337042 ("A technical look at the Dragonfly Titan mission")
>"Flight on Titan is aerodynamically benign as Titan has low gravity and little wind, and its dense atmosphere allows for efficient rotor propulsion.[35] The radioisotope thermoelectric generator (RTG) power source has been proven in multiple spacecraft, and the extensive use of quad drones on Earth provides a well-understood flight system that is being complemented with algorithms to enable independent actions in real-time.[35]"
Obligatory plug for Dragonfly: https://www.nasa.gov/dragonfly/dragonfly-overview/index.html
You _can_ use nuclear power similar to the rover if the lift / weight isn't prohibitive. That means a bigger copter in a thicker atmosphere and lower gravity. Since the power is generated by temperature gradients, cold helps too.
Perfect for Titan.
You _can_ use nuclear power similar to the rover if the lift / weight isn't prohibitive. That means a bigger copter in a thicker atmosphere and lower gravity. Since the power is generated by temperature gradients, cold helps too.
Perfect for Titan.
Wouldn’t an airship be a more viable option for a long term mission on Mars?
I imagine with Mars's thin atmosphere, it'd be hard to get enough buoyancy to lift off.
It won't work at high altitude until we start polluting there. What is air density in one of those nice big craters though?
The atmo is very thin, making the balloon huge relative to the gondola. Some people are quite enthused about it anyway. Including myself.
http://www.gaerospace.com/space-exploration/planetary-aerobo...
With a thick atmo, plenty of sun, and not too much heat / cold in the upper layers. Venus is a _great_ place for balloons.
https://www.nasa.gov/vision/universe/solarsystem/venus-20070...
http://www.gaerospace.com/space-exploration/planetary-aerobo...
With a thick atmo, plenty of sun, and not too much heat / cold in the upper layers. Venus is a _great_ place for balloons.
https://www.nasa.gov/vision/universe/solarsystem/venus-20070...
I was thinking about a rigid body vacuum airship, landing would be easy because all you need to do is lose the vacuum which can be done with a valve and cost no power.
Taking off again can be done over days so you can power it with solar panels if you can’t fit an RTG.
I honestly don’t think winds would be that much of an issue they won’t be strong enough to structurally damage the airship they’ll blow it off sure but not break it apart, and crashing into things isn’t as much of a risk at any reasonable altitudes no buildings no trees, sure there are cliffs and mountains but that can be solved with altitude.
Taking off again can be done over days so you can power it with solar panels if you can’t fit an RTG.
I honestly don’t think winds would be that much of an issue they won’t be strong enough to structurally damage the airship they’ll blow it off sure but not break it apart, and crashing into things isn’t as much of a risk at any reasonable altitudes no buildings no trees, sure there are cliffs and mountains but that can be solved with altitude.
And how would that be packed into a landing shell?
Just thinking about some solutions - origami of both load baring hard materials and connecting flexible ones, or even do something whacky like have a composite fabric balloon that you inflate and the impregnate with resin insitu then when the resin hardens you have a large shell that can be emptied to create a vacuum.
Put rough numbers to it to check feasibility and submit: https://www.nasa.gov/directorates/spacetech/niac/index.html
At least one "garage engineer" was selected this last round.
At least one "garage engineer" was selected this last round.
Someone else already did https://core.ac.uk/download/pdf/161998356.pdf
I'm not aware of any vacuum container that is strong enough to resist buckling while being light enough to be buoyant.
Well, you have low pressure and low gravity working both for you and against you in this case. It doesn't have to be very strong, because atmospheric pressure is so low. But also, the lifting power is also very low, so it would have to be far less dense than a vacuum container would have to be to work on earth.
Low gravity means you need less lift, but low gravity also means the weight of the surrounding air is less so you need more volume. I guess that cancels out.
I suspect it's not practical in atmosphere as thin as Mars, but maybe with a light enough or strong enough material it's possible? At any rate, you'd need an enormous volume just to lift relatively small payloads. And, just filling a balloon with hydrogen would probably make more sense in almost any situation.
At least one good thing Mars has going for it in terms of airships is that CO2 is more dense than Earth's atmosphere. Even nitrogen would be a weak lifting gas on Mars (though it's not available in abundance there as far as I know).
Wikipedia has some useful background information: https://en.wikipedia.org/wiki/Vacuum_airship
Low gravity means you need less lift, but low gravity also means the weight of the surrounding air is less so you need more volume. I guess that cancels out.
I suspect it's not practical in atmosphere as thin as Mars, but maybe with a light enough or strong enough material it's possible? At any rate, you'd need an enormous volume just to lift relatively small payloads. And, just filling a balloon with hydrogen would probably make more sense in almost any situation.
At least one good thing Mars has going for it in terms of airships is that CO2 is more dense than Earth's atmosphere. Even nitrogen would be a weak lifting gas on Mars (though it's not available in abundance there as far as I know).
Wikipedia has some useful background information: https://en.wikipedia.org/wiki/Vacuum_airship
https://core.ac.uk/download/pdf/161998356.pdf
They found a design that can work with current materials and lift 500kg worth of payload.
>”The tensegrity based design using current materials, accounting for losses due to deflection of the membrane and other factors, is capable of 500 kilograms of payload. If trends in the mass reduction capabilities of the tensegrity beam design continue to higher complexities, which is probable, then implementation of a complexity 4 beam will result in 1 to 1.5 tons of payload capacity. In addition, the tensegrity design has been shown to offer full deployability and can be collapsed for transport to Mars.”
They found a design that can work with current materials and lift 500kg worth of payload.
>”The tensegrity based design using current materials, accounting for losses due to deflection of the membrane and other factors, is capable of 500 kilograms of payload. If trends in the mass reduction capabilities of the tensegrity beam design continue to higher complexities, which is probable, then implementation of a complexity 4 beam will result in 1 to 1.5 tons of payload capacity. In addition, the tensegrity design has been shown to offer full deployability and can be collapsed for transport to Mars.”
Steel would work on Earth.
Mars air seems a bit thin for that?
Airships seem somewhat vulnerable to the weather, in practice, as they're always flying. A nice thing about a helicopter is you can land, and it's a station until you take off again.
I don't think we know too much at this point about how Ingenuity will survive dust storms— I see a reddit thread on this but not much else:
https://www.reddit.com/r/space/comments/lo6k73/what_will_hap...
If there was a dedicated mission for a much larger helicopter, it would obviously be important for it to have a story for weathering these things.
https://www.reddit.com/r/space/comments/lo6k73/what_will_hap...
If there was a dedicated mission for a much larger helicopter, it would obviously be important for it to have a story for weathering these things.
Dust storms on Mars aren't dust storms on Earth - we're not really talking damaging winds due to the low pressure. Moreover, since Ingenuity does fly, and blow air around, it's going to have a much better chance of cleaning it's own solar panels.
The weather isn’t that of an issue due to the thin atmosphere. You can land an airship by compressing the lifting gas into a liquid. If you can get enough power reserve at least to do that.
The main issue would be the size of the balloon but honestly if we can make some origami rigid airframe a vacuum airship might actually work.
At that point controlling buoyancy is also less of an issue from a power perspective since you don’t need a large power reserve to land, and when you are on the ground you can wait until you have enough power to create sufficient vacuum in the airship.
The main issue would be the size of the balloon but honestly if we can make some origami rigid airframe a vacuum airship might actually work.
At that point controlling buoyancy is also less of an issue from a power perspective since you don’t need a large power reserve to land, and when you are on the ground you can wait until you have enough power to create sufficient vacuum in the airship.
In general trying to create a vacuum airship is a loosing game because you have to add so much support to prevent it from collapsing that you can't win the race between volume and weight to achieve buoyancy. The thinner atmosphere is a bonus to decreasing the force for a given volume but you simultaneously have to increase the size of the 'balloon' since it's displacing less air for every unit of volume so it has to get bigger which increases the surface area further.
Doing some quick math using the ideal shape of a sphere: Mars surface atmosphere is ~1/60th as dense as the Earth's so you'll wind up with 23x the surface area which at the reduced surface pressures of mars you'd be looking at around 15% of the total forces you'd have to resist. For a sphere that might just push it into the realm of possible options but to get to a 'pure' vacuum you need very fancy and heavy pumps that need cryogenic cooling beyond the difficulty of doing this with an actual blimp shape.
Doing some quick math using the ideal shape of a sphere: Mars surface atmosphere is ~1/60th as dense as the Earth's so you'll wind up with 23x the surface area which at the reduced surface pressures of mars you'd be looking at around 15% of the total forces you'd have to resist. For a sphere that might just push it into the realm of possible options but to get to a 'pure' vacuum you need very fancy and heavy pumps that need cryogenic cooling beyond the difficulty of doing this with an actual blimp shape.
I think I missed a couple things in my initial calculations, like the reduced gravity of Mars, so the number is ~5%. Idk if that brings it back into the realm of possibility though.
Even given the ability to make it you'd likely have issues with the process of getting it there if we're not assembling it in situ.
Even given the ability to make it you'd likely have issues with the process of getting it there if we're not assembling it in situ.
No because you get blown about by the winds. That has led to many destroyed zeppelins on Earth. Can’t afford that on Mars. No ground crew to secure it.
That destroyed zeppelins because there are things they can crash into especially during take off and landing and the winds are strong enough to rip them apart it’s not true for Mars.
The winds are to weak because of the thin atmosphere and there aren’t that many things to crash into.
The winds are to weak because of the thin atmosphere and there aren’t that many things to crash into.
But the zeppelin must be much larger for the same mass (and remember buoyancy is ALSO lower in Mars’ gravity).
[deleted]
Same holds true for a helicopter… before ingenuity no one knew if a helicopter could even fly on Mars.
That’s not accurate. You can do math to show a helicopter can fly on Mars. And a helicopter benefits from the lower gravity, which doesn’t help a zeppelin (as buoyancy is also reduced by gravity but lift force is independent of gravity). So even though lift for both a zeppelin and a helicopter include a density term, the zeppelin is about a factor of 3 worse.
Since helicopters already outcompete zeppelins on Earth, on Mars where helicopters have a factor of 3 advantage over zeppelins, it’ll have an even harder time.
It’s equivalent to a zeppelin at around 100,000 ft at Earth. Possible, but not very practical.
Since helicopters already outcompete zeppelins on Earth, on Mars where helicopters have a factor of 3 advantage over zeppelins, it’ll have an even harder time.
It’s equivalent to a zeppelin at around 100,000 ft at Earth. Possible, but not very practical.
It’s not about the math it’s about the engineering, NASA did the maths and a 40m diameter evacuated airship can carry a substantial payload on Mars, we however have no real clue on how to build it from an engineering perspective.
If you would’ve asked people 10 years ago about flying helicopters on Mars plenty of them would say it’s not possible not because the math doesn’t work out, but because of what requirements the math spits out.
I can do the math for a helicopter for galactic hydrogen, it doesn’t mean engineering can make one. However a vacuum airship on Mars is very much possible, it’s just a heck of an engineering challenge but if you want to get to large payloads not to mention any substantial flight time it’s by far more realistic than a helicopter.
If you would’ve asked people 10 years ago about flying helicopters on Mars plenty of them would say it’s not possible not because the math doesn’t work out, but because of what requirements the math spits out.
I can do the math for a helicopter for galactic hydrogen, it doesn’t mean engineering can make one. However a vacuum airship on Mars is very much possible, it’s just a heck of an engineering challenge but if you want to get to large payloads not to mention any substantial flight time it’s by far more realistic than a helicopter.
Fine, engineering it is. And 10 years ago, regardless of what random people on the Internet would've said, we still had the technology to do a Mars helicopter (although the optical navigation has improved and become more lightweight, that could've been offloaded to the rover). It has been studied for decades and we've had good enough solar, batteries, and motors 10 years ago.
A zeppelin could in principle work on Mars, but it'll be worse than a helicopter, all things being equal. Weather balloons can work fine at those air pressures, but they don't control their position.
A zeppelin could in principle work on Mars, but it'll be worse than a helicopter, all things being equal. Weather balloons can work fine at those air pressures, but they don't control their position.
Batteries are better now than 10 years ago. Motors are better than 10 years ago. Solar is better than 10 years ago. Computers are better than 10 years ago. Each is not a huge amount better, but the improvements multiply out.
Not more than about 5-10% (at least at state of the art). Computers are the biggest argument, but again that's off-loadable to the rover. Again, if anyone said 10 years ago that a helicopter on Mars was not realistic, then they didn't know what they were talking about (it's funny how people who style themselves skeptics will learn like 5 facts about some place and then crown themselves an expert). I explored a similar but more advanced concept professionally about ~5 years ago.
0.9^4 = 0.66
34% better, in aviation, may easily make the difference between practical and not. In the case of Ingenuity, it appears to have made the difference between a need for custom SotA vs. COTS kit.
What computing could usefully be offloaded to the rover is very limited. Compressing video, maybe, and that just for power budget. I think Ingenuity has >10x MIPS than Perseverence.
34% better, in aviation, may easily make the difference between practical and not. In the case of Ingenuity, it appears to have made the difference between a need for custom SotA vs. COTS kit.
What computing could usefully be offloaded to the rover is very limited. Compressing video, maybe, and that just for power budget. I think Ingenuity has >10x MIPS than Perseverence.
More like .95^3=86%, at worst. There really hasn’t been that much change in motor performance and even battery is small (5%) as the chemistry Ingenuity used already existed. Solar has changed maybe 3%, at most.
Reduce Ingenuity’s flight time by 10%, and it would still be practical.
Reduce Ingenuity’s flight time by 10%, and it would still be practical.
[deleted]
FWIW, based on my napkin math you need ~7m diameter balloon filled with hydrogen to lift 1kg of mass (including its shell).
Why do so many website disable zoom? Why?!
If you're looking for a better resolution version of the concept image, as far as I know there isn't one. The original is here, and it's not great: https://www-robotics.jpl.nasa.gov/tasks/showBrowseImage.cfm?...
I just wanted to see the folding concept at the given resolution, just bigger, like God and my pinch gesture intended. No cigar.
Opening the image in another tab then zooming then I suddenly wonder why on Earth this is required. I know it's not malice, but there must millions of people with sub 20:20 vision who don't want to enable the screen magnifier when pinch is ALREADY A THING.
Opening the image in another tab then zooming then I suddenly wonder why on Earth this is required. I know it's not malice, but there must millions of people with sub 20:20 vision who don't want to enable the screen magnifier when pinch is ALREADY A THING.
Jack Parsons will just have to do some real funky stuff to get more plans and technology to make this real :)
Lots in here, taking me time to unpack.
Kind of blue-sky - 30kG is heavy, so maybe its all moot - who's going to dedicate that much mass to this project.
Any geology it does, will be contaminated by rotor wash scrubbing the surface material when it lands. Is that an issue? Maybe its a benefit.
Can it really react to sample inaccessible places? What is the response time between capturing an image of a face, and getting a response from Earth saying "take a sample!"? Is it even within the battery life/flight time?
Can it range outside the rover line of sight? What about radio relay to the orbiter? Surely it can't track that itself, especially in flight. That level of independence may be a pipe dream.
I'm in favor of a drone element to the next mission, as long as it doesn't instantly get lost or broken.
Kind of blue-sky - 30kG is heavy, so maybe its all moot - who's going to dedicate that much mass to this project.
Any geology it does, will be contaminated by rotor wash scrubbing the surface material when it lands. Is that an issue? Maybe its a benefit.
Can it really react to sample inaccessible places? What is the response time between capturing an image of a face, and getting a response from Earth saying "take a sample!"? Is it even within the battery life/flight time?
Can it range outside the rover line of sight? What about radio relay to the orbiter? Surely it can't track that itself, especially in flight. That level of independence may be a pipe dream.
I'm in favor of a drone element to the next mission, as long as it doesn't instantly get lost or broken.
I interviewed Bob and wrote this article, so I can answer a few of these.
I think JPL's idea is that MSH would be a dedicated helicopter mission, rather than piggybacking on some other mission, so it wouldn't be eating up the mass budget of another lander or rover.
Similar to Ingenuity, the flights would be autonomous but the science wouldn't be. MSH would fly up to a cliff face (or whatever), take pictures, land, ask Earth where to sample, and then make a second flight to do the sampling.
MSH would be able to communicate with orbit directly and would not need rover or lander support.
I think JPL's idea is that MSH would be a dedicated helicopter mission, rather than piggybacking on some other mission, so it wouldn't be eating up the mass budget of another lander or rover.
Similar to Ingenuity, the flights would be autonomous but the science wouldn't be. MSH would fly up to a cliff face (or whatever), take pictures, land, ask Earth where to sample, and then make a second flight to do the sampling.
MSH would be able to communicate with orbit directly and would not need rover or lander support.
> MSH would be able to communicate with orbit directly and would not need rover or lander support.
Does that mean it wouldn't be powered by an RTG like the last few missions? Or do you just mean that the MSH will have its own comms independent of a supporting rover/lander?
Does that mean it wouldn't be powered by an RTG like the last few missions? Or do you just mean that the MSH will have its own comms independent of a supporting rover/lander?
JPL has run the numbers on this as part of the engineering study. The solar panel shown in the concept image (in the center) charges a battery that gives MSH a 10km range or 5 minutes of hover time after charging for a day. It would have its own comms that could reach orbit.
Ooof that's hard to swallow :(. Would the MSH be so productive that it makes up for the limited operating time? Is mission planning so meticulous that it would be a bottle neck anyway? What about winter?
Whats the power budget for instruments during/after flight?
Whats the power budget for instruments during/after flight?
This is all the next step. If they end up putting together an actual mission proposal, they can factor in power budgets for specific science instruments, sun angles and seasonality at the landing site, etc, but they're not quite there yet.
Not sure what you mean by limited operating time, though- if you mean that MSH has to spend 50% of its time charging, that's true, but relative to a rover, it can travel so much farther and faster that JPL is arguing it more than makes up for it.
Not sure what you mean by limited operating time, though- if you mean that MSH has to spend 50% of its time charging, that's true, but relative to a rover, it can travel so much farther and faster that JPL is arguing it more than makes up for it.
The rotors would have to be massive to lift 30kg, that may be a stumbling block as it’ll require folding and so on.
Seems like it would need a lander at least for recharging right?
If you're interested in the details of what goes in to developing rotors for a helicopter for an atmosphere we've never built in before you should check out this talk:
https://doi.org/10.52843/47ly7q
Thanks! In scaling up the fragility of the material seems very likely to be a big factor, cube-square law and so on. I wonder if there’ll be physical testing of proposed designs, are there even near-vacuum wind tunnels?
A lot of that talk compares theoretical results with experiments in a low-pressure wind tunnel (see e.g., the slide at this point https://cassyni.com/events/6GYLBKG5pBd4su8dm9A9FB?t=255.0s for a reference).
It's quite a simplistic (2d) setup however. I'm not aware of any more complex experiments.
It's quite a simplistic (2d) setup however. I'm not aware of any more complex experiments.
You can see how the whole thing would fold up in the linked article, there's an image from the white paper that shows MSH fitting into the same size aeroshell Mars Pathfinder used. It would run on solar power and recharge itself, just like Ingenuity.
Thanks, for some reason I had a brain fart and thought it’s one giant rotor.
Also, the rotors would blow away dust on the landing site, which may be a problem if you want to research dust, but may be an opportunity if you want to see what's beneath it.
Hopefully by the time this thing is ready to be built SpaceX have the Starship flying. Getting payload to Mars is going to get a lot cheaper if they hit even half their goals (even if we're just launching the rocket that goes to Mars on top of a Starship).
Imagine deploying 100 of these helicopters deployed from a single Starship.
>Kind of blue-sky - 30kG is heavy, so maybe its all moot - who's going to dedicate that much mass to this project.
if it is delivered by Starship - and timeframe wise i guess it will be so - then there can be tens of those delivered while not being an even the main mission payload.
if it is delivered by Starship - and timeframe wise i guess it will be so - then there can be tens of those delivered while not being an even the main mission payload.
I’m looking forward to the swarm robotics Starship could enable. If we really get to the point where we are sending thousands of tons of payload to Mars (building a city) then we could have lots of cheap rovers instead of one big one. I designed a 3D printed plastic rover and I’m super curious how it would behave in Mars. An aluminum framed version with injection molded gears would be much more robust while staying low cost. And it can drive over very large obstacles:
https://youtu.be/gqLQ5Ht8YE0
https://youtu.be/gqLQ5Ht8YE0
significant share, by mass, of the parts of such cheap simple rovers would probably be 3D printable - say using something like sand, clay or regolith laser sintering - right there on Mars. Basically one of the most important things to be solved on Mars would be to substitute as much as possible with locally produced components (kind of like Russia after international sanctions in 2014 :) That in particular means that the original designs should be very robust and simple in order to be amenable to such a local production. Kind of like do we want to bring rubber wheels all the way from Earth or may be we can locally produce something which would most probably be worse than rubber and thus the original design should account for increased vibration and roughness of the resulting ride.
Yes local materials production on Mars will be important. But I think there will be a period before that is running where we could still send like ten simple rovers and that would be an interesting mission compared to how we have been doing it.
One thing of note, it’s too cold on Mars for rubber (as far as I can tell). The tires are one part of my robot that wouldn’t work. NASA developed some elastic-mode Nitinol tires that would do the trick.
One thing of note, it’s too cold on Mars for rubber (as far as I can tell). The tires are one part of my robot that wouldn’t work. NASA developed some elastic-mode Nitinol tires that would do the trick.
"You'd shoot a little projectile from the drone that embeds itself in the cliff wall, and then you'd reel it back in with a sample."
Is that what would happen? How does the embed de-embed itself? How does the reeling in not end up pulling the drone closer to the cliff?
Is that what would happen? How does the embed de-embed itself? How does the reeling in not end up pulling the drone closer to the cliff?
I asked Bob about this. There are a bunch of options, but one way to do it is that you use a hollow projectile that takes a core sample, and then you just reel back in the core while the rest of the projectile stays in place.
Wow! Never did I expect that kind of response when I asked a random question on an internet forum. Thanks for the follow up!
mainly, precise tolerance engineering.
ofc we don't already know the exact composition and hardness of said cliff walls, so your question stands.
ofc we don't already know the exact composition and hardness of said cliff walls, so your question stands.
30kg flying on Mars? Wow! How massive is this thing gonna be. Ingenuity is already 1.2 metres across, so it’s not exactly small. This thing is gonna be massive.
> 30kg flying on Mars? Wow! How massive is this thing gonna be?
It’s gonna be 30kg =P
…
I’ll show myself out.
It’s gonna be 30kg =P
…
I’ll show myself out.
Is there a reason they don't send Boston dynamics robots?
It was in the news yesterday that NASA is working with Boston Dynamics to potentially explore caves on Mars with walking robots: https://www.cbsnews.com/news/nasa-human-like-robots-boston-d...
Radiation hardening is a big issue. Commercial components could fail due to ionizing radiation, at a high enough rate that it puts the mission at risk. Also just genera design. Robots that can be easily repaired and recharged have different design parameters than those that have to go to Mars.
True, it won't be easy, but better than sending people there. Spend some billions and in 10 years bring some robots, and explore the planet without risking any human life.
I just hope they have more-experienced engineers to program its control system than on Ingenuity. They were super-lucky on that one. There is absolutely no way that time-registration navigation bug should have been able to have any effect whatsoever on the vehicle's dynamic stability. (You may be sure it wouldn't have, if the Nav guy had done the attitude control too.)
I disagree, it just shows that NASA was willing to take more risks/ fail-fast approach. "if you aren't failing you're not trying hard enough".
That is very far from the sort of risk they mean. Incompetence is never the place to squander your risk budget. There is plenty of competence on the ground, and it is not slower.
> even for a vehicle that was not designed to do much in the way of science at all
Hey hey, demonstrating something is simply possible is definitely "doing science".
That's half the battle!
> We were just telling the scientists, think big
"But not too big..." - Every engineer after the first guy.
Hey hey, demonstrating something is simply possible is definitely "doing science".
That's half the battle!
> We were just telling the scientists, think big
"But not too big..." - Every engineer after the first guy.
That solar panel on the top seems awfully small to me. If you look at the solar panel on the helicopter that's already on mars, its almost 3 times bigger than the body. This just looks tiny in comparison.
It's hard to get a good sense of scale from the image, but the solar panel on the concept is about 0.5m in diameter. JPL has run the numbers as part of their engineering study, and MSH would be able to recharge itself in a day.
This is fan fiction. Nasa as nasa will never reach mars again. China yes, Spacex yes, but not nasa.
Didn't know AeroVironment was involved in Ingenuity. They make a lot of cool and tiny military drones. Personally one of my favourite things is how Ingenuity used a lots of off the shelf hardware.