Mars sample return

AugustusMinimus

Getting ahead of myself a bit with Curiosity just after landing on Mars, but whats the story at the moment with the Mars Sample Return mission that NASA have in planning.

Just how feasible is this. Would this take a 1 stage or 2 stage setup with a return vehicle having to be sent independently of a rover which would provide the return vehicle with the sample.

While the gravity of Mars is a lot less than the earth and Mars' atmosphere is a lot thinner, wouldn't a robotic launch from the surface to return the sample to earth prob be the most complicated thing NASA has ever done. Try to land the return vehicle, which would weigh an awful lot considering all the propelant needed would be an incredibly daunting task.

namloc1980

I believe NASA have indefinitely postponed a sample return mission due to the cost and their dwindling budget. They pulled out of the joint 2018 rover mission with ESA due to funding uncertainty. Unfortunately Obama has proven to be no friend of NASAs planetary exploration program. ESA are now trying to hook up with the Russians to progress the 2018 rover mission but that is in doubt. The next decade will be pretty slim on the planetary exploration front it seems.

Cork boy 55

The objective is to find life or traces of life on Mars 100% beyond all doubt.

What can a rover or lander not do with the samples that can be done on earth?

2 stroke

Why do these things have to be all rocket science, surely the best way to get a sample back from mars is a lighter than atmosphere lander that would float a sample up from the surface to rendezvous with the return vehicle.

ThatDrGuy

it would have to be near vacuum to get very high on mars

AugustusMinimus

2 stroke wrote: »

Why do these things have to be all rocket science, surely the best way to get a sample back from mars is a lighter than atmosphere lander that would float a sample up from the surface to rendezvous with the return vehicle.

The atmosphere of Mars is only .6% as dense compared to the Earths atmosphere. Surely this wouldn't allow this to work.

namloc1980

2 stroke wrote: »

Why do these things have to be all rocket science, surely the best way to get a sample back from mars is a lighter than atmosphere lander that would float a sample up from the surface to rendezvous with the return vehicle.

Unfortunately the Martian atmoshpere is extremely thin - average Martian atmospheric pressure is about 0.6% of Earth at sea level. This means you would need an ENORMOUS balloon to float on Mars and a vast vast amount of helium to fill it with. To get all that to Mars would use up huge resources in terms of fuel, weight etc.

In addition a balloon on Mars would burst at a relatively low altitude because of the very low pressure i.e. the balloon would expand to bursting point as there wouldn't be enough air pressure pushing on it from the outside to keep it together. On Earth large weather balloons burst once they reach a height of c.100,000 feet where air pressure is about 0.162 PSI. On Mars the surface pressure is 0.087 PSI!!

namloc1980

ThatDrGuy wrote: »

it would have to be near vacuum to get very high on mars

No it's the opposite. The denser the atmosphere the better a balloon works and the higher it will float.

ThatDrGuy

namloc1980 wrote: »

No it's the opposite. The denser the atmosphere the better a balloon works and the higher it will float.

I meant the inside of the balloon would have to be near vacuum to float in such an athmosphere ie the hypothetical http://en.wikipedia.org/wiki/Vacuum_airship

AugustusMinimus

The benefit of having such a thin atmosphere on Mars it that it takes much less propelant to launch from the surface than what it would have been if Mars had a thick atmosphere.

namloc1980

ThatDrGuy wrote: »

I meant the inside of the balloon would have to be near vacuum to float in such an athmosphere ie the hypothetical http://en.wikipedia.org/wiki/Vacuum_airship

Oh got ya.

2 stroke

By lighter than atmosphere, I wasn't specifically thinking baloons but rather new technology & materials. Rather than fill the lander with tonnes of helium, vacuum it & maybe use solar power for some lift. I don't think it would be right to polute their planet with a massive volume of our fossil fuels just to get a sample back. Those rocket blasts near the lander upset me a little.

namloc1980

2 stroke wrote: »

By lighter than atmosphere, I wasn't specifically thinking baloons but rather new technology & materials. Rather than fill the lander with tonnes of helium, vacuum it & maybe use solar power for some lift. I don't think it would be right to polute their planet with a massive volume of our fossil fuels just to get a sample back. Those rocket blasts near the lander upset me a little.

Rocketry is a proven technology. There is no proven way of creating a vacuum filled(!) vehicle that could float because the structures required to maintain the vacuum, and to prevent the vacuum vessel from collapsing in on itself, would invariably weigh too much and prevent it from floating.

AugustusMinimus

2 stroke wrote: »

By lighter than atmosphere, I wasn't specifically thinking baloons but rather new technology & materials. Rather than fill the lander with tonnes of helium, vacuum it & maybe use solar power for some lift. I don't think it would be right to polute their planet with a massive volume of our fossil fuels just to get a sample back. Those rocket blasts near the lander upset me a little.

The atmosphere of Mars is basically all CO2 as it is anyways.

Eventually if we do want to terraform the planet, filling the atmosphere with super greenhouse gases would be an ideal start.

Hal1

All we need to do is find this:

:pac:

Cork boy 55

Cork boy 55 wrote: »

The objective is to find life or traces of life on Mars 100% beyond all doubt.

What can a rover or lander not do with the samples that can be done on earth?

Can anyone answer this?

I mean what technically can we do on earth with the samples that we cannot do on Mars with automation?

I.e. to find life or traces of life 100%

What's the piece of kit or kits we need to send there?

namloc1980

Cork boy 55 wrote: »

Can anyone answer this?

I mean what technically can we do on earth with the samples that we cannot do on Mars with automation?

I.e. to find life or traces of life 100%

What's the piece of kit or kits we need to send there?

I don't think we could ever send the range of analytical instruments available on Earth to Mars due to the enormous cost. In addition the returned samples could be analysed by different scientists and the results could be compared and contrasted etc. Also a returned sample has the benefit on continuous analysis, weeks, months and even years after the sample was returned allowing detailed measures of any possible changes in the sample, and also new technologies developed on earth in the future could be used to examine the returned sample. For obvious reasons the scientific instruments on something like Curiosity can't be upgraded and if they break they'll stay broken.

LFCFan

I know all precautions would be taken to prevent contamination of any samples returned to Earth from Mars but could they be 100% sure that there was no contamination and that any findings were not just from contamination? Surely the best place to do the test etc are on Mars?