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Presuming that we could build on what we learned from Ingenuity, and we built, launched, and landed a copter platform that was designed to autonomously map the surface of Mars, what challenges would it be worth undertaking?

Pros:

Better than satellite imagery:

  • Higher resolution images by navigating closer to the surface.
  • Not obscured by overhangs, outcroppings, cliff faces.
  • The ability to go into caves

Better than satellite data:

  • more sensors, more data, such as low, residual magnetism
  • much better local temperature readings

Cons:

Speed

Cost

  • One satellite that does not land is going to be significantly cheaper than a bunch of copter drones on the surface.

Would it be worth attempting to build this to map the surface of Mars, or do we already have enough satellite data and there is not more to learn?

nycynik
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  • I think "Challenges to..." is a good SE question, whereas "Would it be worth...." is harder to answer in a fact-based way. – uhoh Apr 22 '21 at 23:31
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    It appears that the Mars Orbit is so thin that you can use an ion engine for station keeping down to 150 km, quite a bit lower than what's used for earth mapping satellites. And obviously that's also with less atmospheric distortion. – MSalters Apr 23 '21 at 11:59

6 Answers6

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Presuming that we could build on what we learned from Ingenuity, and we built, launched, and landed a copter platform that was designed to autonomously map the surface of Mars, what challenges would it be worth undertaking?

You are asking for far too much, and because you are asking for far too much, you are missing the point of Ingenuity, and its follow-on helicopters, which will be better in terms of reliability and in terms of mapping.

Look to our own planet. The Earth has multiple Landsat satellites. Landsat imagery was perceived as very high resolution 49 years ago, when the first Landsat satellite was launched. Landsat imagery is no longer perceived as high resolution. We have several dozen military-grade and commercial-grade satellites orbiting the Earth that make Landsat imagery look like a child's crayon drawings. We have thousands upon thousands of airplanes, helicopters, and drones whose aerial photographs make even the highest resolution imagery from modern Earth observing satellites also look like a child's crayon drawings. Yet there remain vast expanses of the Earth's surface that are mapped at Landsat level accuracy.

We have not come anywhere close to mapping the surface of the Earth using aerial photography. That said, aerial photography has helped a lot, a whole lot. But it is not complete. Asking for it to be complete on Mars is asking far too much.

What will be helpful is to have helicopters do a better job of identifying objects of interest and a better job of mapping the way forward for Mars rovers than those objects of interest / paths toward those objects of interest identified by imagery from the rover itself or from satellites. Think of all the times a Mars rover has had to backtrack because satellite and rover imagery did not see obstacles. Think of all the times a Mars rover has investigated what appeared to be an object of interest that turned out to be an object of no interest. There were also probably times a Mars rover did not investigate what should have been an object of interest that rover and satellite imagery missed.

Better identification of paths and better identification of objects of interest are how a Mars helicopter can be beneficial. Complete mapping of Mars is not needed.

David Hammen
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As has been stated in other answers, a whole planet aerial survey would be excessive, but detailed surveys of specific regions of interest would be where aerial surveys would be most beneficial.

I can envisage a phased usage of flying vehicles on Mars.

  • To assist with initial exploration of Mars by helping rovers find targets and helping find a better way for rovers to reach points of interest on the surface.
  • During the decent of Apollo 11 on the Moon, there was a problem with unexpected boulders at the targeted landing site. Aerial surveying could provide better detail of proposed sites for landing and bases on Mars.
  • When bases have been established flying devices can undertake aeromagnetic surveys to assist with mineral exploration of Mars. This would require a robust flying device with an energy source that would allow for long flying times and easy and quick replenishment of the energy source.
Fred
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No. The problem is bandwidth. The highest resolution camera in Mars orbit right now is the HiRISE camera. It can image the surface of the planet with a resolution of about 25 cm resolution. It has only, in 15 years, been able to capture around 4% of the planet. The reason why they haven't been able to send back more data is because of bandwidth limitations. And MRO has the highest bandwidth of any spacecraft there.

A fleet of helicopters, assuming that they worked fantastically and with minimal effort, would still be limited by bandwidth. A satellite can have a larger dish, which allows for higher bandwidth. Thus, a satellite will always be a better option, so long as the goal is to send the data back to Earth.

Helicopters, as others have mentioned, could allow for a really high resolution scan of a specific area, which might be useful. One application might be to send these to do scouting missions for a Starship mission to Mars, for instance. But as weight is such a premium, they really need to be reasonably close to a larger spacecraft to transmit their data home, at least for now.

PearsonArtPhoto
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Would it be worth to globally map Mars' surface with a higher resolution than ~20m/pixel using swarms of automated helicopters/drones instead of a single satellite ?

No, not at the moment.

Mars Express has produced an almost complete high resolution surface model of Mars. I am not sure if the resolution includes elevation data. This is a 200m resolution digital elevation model of Mars.

Mars' surface area is comparable to Earth's land surface area. A 'bunch of helicopters' needed far too long compared to a single or a small number of satellites.

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How many bits would be needed to map the full surface of Mars?

The surface is 149 million square km, that is 149E12 square meter. If we want to store pixels of one square meter, three bytes for color, we need 447E12 bytes of storage. A terabyte disk stores 1.099E12 bytes. So we need 407 disks with 1 terabyte each for storage. Using 16 terabytes disks reduces the number to only 26.

A transfer of all that data with a bandwidth of 1 megabit per second would take 447 * 8 million seconds or 113 years.

Uwe
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On Mars, a helicopter can:

  • Fly to altitudes otherwise easily reachable by an instrument cluster on a rover's mast, while carrying a severely minimized instrument package.
  • Consume days' worth of accumulated energy in a matter of minutes.
  • Fail catastrophically if a blade strikes any obstacle, in flight or on landing.

Realistically, you are not flying helicopters into caves or up close to a cliff, or anywhere far from a nice level, obstruction-clear landing spot with good all-day sunlight. An articulated mast/boom on a rover (or other approaches such as sub-rovers tethered to winches) would be able to access caves and cliffs while carrying more instruments, being able to spend more than a few seconds investigating sites of interest, moving through terrain a helicopter wouldn't risk landing on, and covering more ground while consuming far, far less power.

Christopher James Huff
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  • So, why build Ingenuity at all? – Polygnome Apr 23 '21 at 12:55
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    @Polygnome PR? People do get really excited about helicopters on Mars for some reason. The rover's covered a few hundred meters already and is off doing other stuff, but it's mainly the helicopter's brief hops that are in the news. A better question might be: "why build another one?" – Christopher James Huff Apr 23 '21 at 14:20
  • @ChristopherJamesHuff Ingenuity is a technology demonstration article. See also Mars Helicopter Technology Demonstrator and Ingenuity is what is known as a technology demonstration – a project that seeks to test a new capability for the first time, with limited scope. Next stop... Titan? (at least it won't overheat) – uhoh Apr 23 '21 at 14:29
  • "Fly to altitudes otherwise easily reachable by an instrument cluster on a rover's mast" Perseverance's Mast is 7 feet long. making it longer adds more mass, which eats into the mass budget. Ingenuity was allowed to climb to 16 feet on the second flight, and can technically reach far higher. – Polygnome Apr 23 '21 at 14:32
  • Dragonfly will be a quadcopter but will still likely benefit a lot from experience with Ingenuity. – uhoh Apr 23 '21 at 14:34
  • @Polygnome Perseverence's mast is designed for other purposes, you wouldn't simply make it taller. Ingenuity can reach 5 m, and you could easily build a mast that reaches higher for similar mass. – Christopher James Huff Apr 23 '21 at 15:15
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    @uhoh Titan is a wildly different flight environment, there's nothing Ingenuity could learn that would be applicable there. And as far as helicopters on Mars go, there's no significant room for improvement on Ingenuity's capabilities. It's not a Wright Flyer, it's an advanced helicopter produced in the 2020s by JPL. What you see here is what you get. – Christopher James Huff Apr 23 '21 at 15:18
  • @ChristopherJamesHuff Sure, you could. But you'd still need to make sacrifices. A second arm just for reaching higher eats up mass budget on the rover. – Polygnome Apr 23 '21 at 15:45
  • @ChristopherJamesHuff navigation? communication? software? thermal protection (keeping batteries and electronics alive) in a c-c-c-cold environment? There's a lot more to the whole thing than aerodynamics. – uhoh Apr 23 '21 at 21:35
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    @uhoh no, no, no, and really no. Mars has zero advantages over Earth for development of the first three, and a 0.006 atm ~200 K environment of Mars is a tropical paradise compared to the 1.45 atm 94 K nitrogen experienced on Titan. The power and thermal control problems, and the solutions to them, are wildly different. Dragonfly will have to use an RTG for power and heating, something the Titanean atmosphere will enable as much as it makes necessary...on Mars the RTG would produce less power and would be too heavy to lift. – Christopher James Huff Apr 23 '21 at 23:37
  • I'm starting to come around to your point of view, but perhaps less "wildly" so ;-) – uhoh Apr 23 '21 at 23:48
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    Downvoted. If I could downvote multiple times I would do so. Almost every bit of this answer is wrong. It ignores that Ingenuity is a technology demonstration article. Future Mars helicopters (and there most likely will be future Mars helicopters given that Ingenuity has had two successful flights) will be more capable and will have much better guidance, navigation, and control. For example, see An Advanced Mars Helicopter Design. – David Hammen Apr 24 '21 at 06:55
  • This is super depressing :) But I take from this - that the max height of say 50m is not just what ingenuity is limited to, but it is what all powered aircraft flight is limited to. (I don't know the term for not-a-rocket, I mean plane-like flight.) This makes the whole idea of mapping silly. Thanks for your answer. :( – nycynik Apr 24 '21 at 21:49
  • this post does not answer at all to the question about MAPPING, it's completely offtopic. – jumpjack Apr 30 '21 at 07:43