Mission to Tharsis on Mars or Valles Marineris

[fredinno]

Would it be possible and economical to send a Spirit-size rover to Mars to study the Tharsis or Valles Marineris Regions? I heard for Viking, high-elevation areas could not be reached due to the thinner atmosphere:P. Is this still true, and how much would this affect a mission to these two areas?

[kenbobo]

If I know anything about friction and how rovers work, they should work on any surface that has gravity, I don't get why pressure has any difference. I suppose it would be possible.

[FleshJeb]

I don't get why pressure has any difference. I suppose it would be possible.

Just like on Duna: Aerobraking and parachuting to the higher altitudes is hard. Curiosity is so massive they had to do the Seven Minutes of Terror landing.

Valles Marineris is pretty deep and wide, landing there should be no problem, but I bet the terrain at the bottom is pretty chaotic.

I was just about to suggest a drone airplane mission down the canyon, when I googled it: http://www.jmcgowan.com/marsplane.html

The Tharsis Bulge, on the other hand? Hoo boy, that looks like a tough mission.

[RainDreamer]

Design some really tough but light weight rover and lithobrake!

[Scotius]

Aside from planetology science experiments, you wouldn't be able to see a lot in Tharsis area. Those shield volcanoes are so freakishly big, from the perspective of the rover you would see only terrain gently sloping upwards. Valles Marineris on the other hand...hooo boy! Just imagine getting close to the edge of the cliff, and looking down. And down. And even further down into the maw of the biggest canyon in entire Solar system. My agoraphobia tingles already

[Nibb31]

Lower altitudes are easier, because you have more margin for parachutes. I don't think there are any latitude constraints like on the Moon, MPL was able to land at a pretty high latitude, and small adjustments during the cruise phase can be used to target your insertion.

However, they can't really do pinpoint landings yet, so it would be risky. They need a relatively flat and open area to land. The landing ellipse for Curiosity was initially 25x20 km. You wouldn't want to be blown onto the side of the canyon, or land just on top and roll down, or land at the bottom on top of a rock.

[fredinno]

Could you land a rover there more safely using parafoils? It seems to be able to combine a lander with a glider. I know that the foil would had to be pretty big though.

[prophet_01]

With the massive signal delay, a glider is tricky. It would either need to be a highly automated system, capable of performing the landing on it's own or you bring a manned mission near mars and let them do the piloting. Both isn't exactly easy or something we've done already. But probably not impossible.

[SargeRho]

Aircraft can already fly on their own. Drones aren't piloted directly a lot of the time.

[KerikBalm]

Could you land a rover there more safely using parafoils? It seems to be able to combine a lander with a glider. I know that the foil would had to be pretty big though.

I did the calculations once for what the landing/stall speed of a hangglider would be.... it was really really fast even at the bottom of the Hellas Basin.

Also.... have you seen pictures of the ground on mars? rocks all over the place...

Not the place to touch down at something like 300 km/h horizontal, and ~40 km/h horizontal.

Then you have to figure that Tharsis is much much higher, with thinner air.

These concets for martian gliders don't really seem feasible... the air is just too thin.

Of course, if you made something like this:

You might get to a reasonable landing speed on Mars, but then its so fragile with so little payload.... why bother?

You're not going to land a rover with that.

If you could predict the weather very well, and if the high wind speeds were relatively smooth (not gusty)... you might be able to pull off a landing by landing into the wind... but... yea... that's not reasonable

[SargeRho]

How about inflatable wings, with Helium, which would allow one to create very large, very light wings?

[KerikBalm]

The lifting power of helium is due to displacing a mass of air (Mostly Nitrogen) with a smaller mass of Helium Air.

Helium has no lifting power in a vacuum, because the mass of stuff that it displaces is essentially zero.

For our purposes, Mar's atmosphere is a vacuum.

Heliums lifting power at the Mars datum is less than 1/100th of its lifting power at Earth's Sea level.

While the Martian atmosphere at the bottom of Hellas, or even Datum may be significant enough to not consider it a vacuum... if you are talking about landing on the Tharsis region, you're really going to find it to be not much different from a vacuum for aerodynamic and bouyancy purposes.

[SargeRho]

The idea isn't to create a zeppelin, but the lightest and largest lifting surface possible in a small package.

[KerikBalm]

I doubt the weight of a 2nd surface and sealing it would be offset by the insignificant bouyancy.

There is already a reason that super light weight gliders don't have inflatable wings.

The surface to volume ratio is horrible, so you have a lot of membrane for very little volume.

The incredibly reduced bouyand force on mars just makes it worse.

[prophet_01]

Aircraft can already fly on their own. Drones aren't piloted directly a lot of the time.

While this is true, there is definitely a difference between flying a drone and landing one in a terrain that you don't rly know much about. It's not exactly an easy task to create a software that can land a quite heavy drone in potentially very rough terrain. On top of that we never landed anything in such a low pressure enviroment horizontally (if that is even possible).

We lack experience at this and have problems to predict the weather conditions and we only know the surface material from satelite images. I'm not sure that a program can deal with that. Even if there is a way to do this from an engineering point of view, I'd prefer the remote controled variant with an astronaut in orbit around mars or on a fly by mission.

I have the apollo 11 last minute landing correction in mind. Although software and satellite imaging have improved significantly since then, unpredicted problems are still fairly common when landing in new places (philae lander).

But I still wonder if a glider could be used to get at least somewhat close to the target. You could ditch the wings before the final landing and do that last bit with regular engines. I'm not sure though if it could even glide long enough to perform any meaningfull course corrections.