NASA - Perseverance, Mars 2020 Rover : Discussion

[NovaSilisko]

Here's something that's occured to me recently: If Mars 2020 is still functioning after all the samples have been gathered, couldn't it become in effect its own fetch rover? Land a static MAV, and have M2020 retrace its steps, pick up the sample canisters, and deliver them to the MAV? It seems like if that could be done, it would be a major reduction in costs since you no longer need to develop a separate fetch rover. But of course there is inherent risk to it, since you'd be relying on old hardware.

[redliox]

Here's something that's occured to me recently: If Mars 2020 is still functioning after all the samples have been gathered, couldn't it become in effect its own fetch rover?

Possibly, although earlier Blackstar pointed out the whole point of a cache was to remove risk from the rover.  Engineers might argue this...although a more practical, specific argument would be that the 2020 rover might not be anywhere near the caches when the MSR lander arrives.  Functional or not, it would be doing other things while MSR focuses on loading the caches into itself.  Assuming it's as successful as Opportunity, most likely all it could do would be to watch the MSR landing and ascent from afar.

It would be interesting, on the other hand, to see 2 rovers strolling alongside each other with one functioning as a backup for the other.  This would only happen if 2020 happens to be within a kilometer of where it could be useful...and moreso if NASA management nudges JPL to do so...the odds of which are probably low if 2020 gets an extended life of exploration beyond its cache collection phase.

I'd give it a 1-in-4 chance that the 2020 rover directly helps MSR retrieve its own samples, mainly because it would technically be at the landing site but also likely too far away and engaged in extended science.

[Blackstar]

Here's something that's occured to me recently: If Mars 2020 is still functioning after all the samples have been gathered, couldn't it become in effect its own fetch rover? Land a static MAV, and have M2020 retrace its steps, pick up the sample canisters, and deliver them to the MAV? It seems like if that could be done, it would be a major reduction in costs since you no longer need to develop a separate fetch rover. But of course there is inherent risk to it, since you'd be relying on old hardware.

No. There is simply no way to design a mission based upon the assumption that the 2020 rover will still be operational when the return vehicle gets there.

Think of it like this: the 2020 rover will launch in 2020, arrive in 2021 and be designed to last a Martian year, meaning 2023. The next Mars launch window opens in 2022, reaching Mars in 2023--right at the time that the 2020 rover has reached its design life. Now of course Mars 2020 is going to last beyond its design lifetime. But how long? The next window is 2024, arrival in 2025. Will the Mars 2020 rover be alive then, twice its design lifetime?

Now you also have to figure in programmatic issues--the retrieval mission is going to be expensive. And complicated. And it has to be approved (it is not currently approved). So when is it going to get approved and built? Not for the 2022 window--it is already too late. It's also probably too late for the 2024 window. And keep in mind that the retrieval mission has not been prioritized by the planetary decadal survey. The next decadal will not be produced until around 2021, and if it recommends a retrieval mission as a top priority, that mission will not happen until late in the 2020s.

These things take time, and because of that the mission designers cannot rely upon the Mars 2020 mission to be operational when the retrieval mission gets there.

Launch windows are here:

http://clowder.net/hop/railroad/EMa.htm

[vjkane]

As I understand it, the 2020 rover will not be carrying a canister to hold the sample tubes, so it could not act as the fetch rover.

One advantage of the 2020 plan is that it can cache a larger set up sample tubes (at multiple places) than would be returned.  Scientists on Earth can then take years to debate which sample tubes would be retrieved.  As I understand it, it was difficult to design a canister that would would both securely hold the sample tubes and allow them to be ejected.  This way, specific tubes can be selected and others rejected once the full set have been collected and all the data is analyzed.

[MP99]

Wouldn't it make for a simpler vehicle if it was just able to plug itself into the rover when it needed to?

By the way what's the current thinking of if this is going to hit the 2020 launch window & what with all the fuss about its engine supply will it still be baselined for an Atlas V launch?

Think of the fun of having a copter with rapidly spinning blades landing on the rover with a dust devil hits and those blades start slapping everything on the deck and masts.

If the rover had solar panels, then hovering over the rover should clear dust off the panels?

But, it's solely powered by MMRTG, I understand?

Cheers, Martin

[vjkane]

Think of the fun of having a copter with rapidly spinning blades landing on the rover with a dust devil hits and those blades start slapping everything on the deck and masts.
If the rover had solar panels, then hovering over the rover should clear dust off the panels?

If the copter/drone is included with the 2020 rover, the engineers are very worried about the drone hitting and damaging the rover.  The operational scenario I read had the rover arm depositing the drone on the ground.  Once the rover had moved a substantial distance away, the drone would begin to operate, but never come close to the rover (we are probably talking out tens to a couple of hundred meters).  So no dust cleaning and no aerial shots of the rover on the surface.   

[Star One]

They should put the rover down near some Martian caves and then fly the copter inside. Even if it is only a little way in surely it would be worth it scientifically?

[redliox]

They should put the rover down near some Martian caves and then fly the copter inside. Even if it is only a little way in surely it would be worth it scientifically?

That's a bit far fetched would be a polite way to put it.  NASA might look into the cave mouth from outside, but they would not drive a roughly billion dollar rover into a spot where they might lose radio contact.  The copter might not be able to do much, especially if it doesn't have a light to guide it in, nor would its team want to risk losing contact either.

[Star One]

They should put the rover down near some Martian caves and then fly the copter inside. Even if it is only a little way in surely it would be worth it scientifically?

That's a bit far fetched would be a polite way to put it.  NASA might look into the cave mouth from outside, but they would not drive a roughly billion dollar rover into a spot where they might lose radio contact.  The copter might not be able to do much, especially if it doesn't have a light to guide it in, nor would its team want to risk losing contact either.

But I would think the caves must be high priority targets, being completely unexplored and therefore worth a little risk.

Something else maybe that will have to be left to Space X then.

[Blackstar]

They should put the rover down near some Martian caves and then fly the copter inside. Even if it is only a little way in surely it would be worth it scientifically?

That's a bit far fetched would be a polite way to put it.  NASA might look into the cave mouth from outside, but they would not drive a roughly billion dollar rover into a spot where they might lose radio contact.  The copter might not be able to do much, especially if it doesn't have a light to guide it in, nor would its team want to risk losing contact either.

But I would think the caves must be high priority targets, being completely unexplored and therefore worth a little risk.

Something else maybe that will have to be left to Space X then.

As was proposed on another thread, NASA should just stop doing all this stuff because Elon's going to do it anyway.

Also: unicorns.

[Star One]

They should put the rover down near some Martian caves and then fly the copter inside. Even if it is only a little way in surely it would be worth it scientifically?

That's a bit far fetched would be a polite way to put it.  NASA might look into the cave mouth from outside, but they would not drive a roughly billion dollar rover into a spot where they might lose radio contact.  The copter might not be able to do much, especially if it doesn't have a light to guide it in, nor would its team want to risk losing contact either.

But I would think the caves must be high priority targets, being completely unexplored and therefore worth a little risk.

Something else maybe that will have to be left to Space X then.

As was proposed on another thread, NASA should just stop doing all this stuff because Elon's going to do it anyway.

Also: unicorns.

Kind of my point maybe.

[NovaSilisko]

Kind of my point maybe.

Still not actually certain whether you're serious or not...

[Blackstar]

Kind of my point maybe.

Still not actually certain whether you're serious or not...

Unicorns are deadly serious.

[redliox]

Still not actually certain whether you're serious or not...

Unicorns are deadly serious.

You're giving me flashbacks of the killer unicorn from "Cabin In The Woods" now 'Star 

Getting closer to topic, so the rover is most likely going to set down 3 caches of samples it seems?  Is there going to be a capsule anymore?  If it's going to be caches I'd like to know what they're going to try to do to protect or cluster the tubes together without a capsule.

[vjkane]

Getting closer to topic, so the rover is most likely going to set down 3 caches of samples it seems?  Is there going to be a capsule anymore?  If it's going to be caches I'd like to know what they're going to try to do to protect or cluster the tubes together without a capsule.

My understanding is that they are simply laying the tubes on the ground (presumably they are uniquely marked so a subsequent rover can retrieve just the ones desired).  There have been concerns about the effects of solar heating, so perhaps they'll put them in the shadow of a large rock.

[Blackstar]

Getting closer to topic, so the rover is most likely going to set down 3 caches of samples it seems?  Is there going to be a capsule anymore?  If it's going to be caches I'd like to know what they're going to try to do to protect or cluster the tubes together without a capsule.

My understanding is that they are simply laying the tubes on the ground (presumably they are uniquely marked so a subsequent rover can retrieve just the ones desired).  There have been concerns about the effects of solar heating, so perhaps they'll put them in the shadow of a large rock.

What I heard in a briefing a few weeks ago sounded like they are actually going to have them in containers of about 10. But they could be essentially open rack containers, maybe something like this, possibly with a cover over it to keep it shaded.

[vjkane]

What I heard in a briefing a few weeks ago sounded like they are actually going to have them in containers of about 10. But they could be essentially open rack containers, maybe something like this, possibly with a cover over it to keep it shaded.

That would be neater

[Blackstar]

To clarify: I only heard containers of about 10. I don't know if they will be open rack or sealed.

It strikes me that a certain amount of flexibility might be useful--for instance, taking a few more sample tubes than they actually need so that they can do a final selection based upon the entire sample set.

Put it this way: suppose they take 34 containers, but can only return 30 of them. Having 4 extras could be useful. What if one of the containers does not seal right? Or what if they decide after filling container #30 that container #3 was a low-quality sample and they would rather have a better sample? That way if they fill up 34, they can decide later which ones were of lower interest.

But this is me speculating. They might be planning on taking 30 and returning 30 and that's it.

[redliox]

To clarify: I only heard containers of about 10. I don't know if they will be open rack or sealed.

It strikes me that a certain amount of flexibility might be useful--for instance, taking a few more sample tubes than they actually need so that they can do a final selection based upon the entire sample set.

A rack is better than nothing, open or sealed.  If another rover has to pick it up the least that should be done is to at least wrap the samples in a small gift basket, and by that I mean it's easier for a remote-controlled robotic arm to pick up a rack with a decent handle as opposed to a pile the operators on Earth have to painstakingly spend several hours a piece picking up individual tubes.  If the rack should do anything aside from holding the tubes together, perhaps it should be minimal thermal control; like literally a tinfoil-esque umbrella to mitigate the thermal effects of direct sun.  For something more cost-effective than a full-blown capsule that's the most I'd expect offhand.

Hopefully we see the 2020 team release some progress.

[Blackstar]

There's a Mars 2020 update from March here:

http://mepag.nasa.gov/meeting/2016-03/21_MEPAG_160303_FINAL%20v2.pdf

They are scheduled to go into Phase C (Design and Development) in April/May, so presumably they are about to do that any time now. Considering that they already have a lot of hardware in hand, they should move through this faster than MSL/Curiosity did.