Mars Sample Return Options

[bobik]

Ha-ha, I really expected this from the beginning of the MSR program, it seems the Sample Fetch Rover (SFR) has been cancelled. ESA fell for it again! Well, now ExoMars is really in a pinch. Taking into account the hopeful hints last week and the abruptly cancelled press briefing earlier this week, I guess ESA was taken by surprise by this decision.

[rlorenz]

Sample Fetch Rover (SFR) has been cancelled

This article discusses the use of a couple of sample fetch helicopters.
https://www.bbc.com/news/science-environment-62234196

Even two or three helis would be much less mass than SFR, so presumably can fit in a single-lander architecture. The concepts I have seen (Aerovironment presentation at IEEE) have Ingenuity-sized helicopters with a redesigned propulsion motor to stretch the range/longevity by better efficiency and larger heatsinking. A small few-DOF arm would pick up a single sample tube at a time. It also had wheels for the meter-scale mobility to get within an arms length of the tube, and to roll up to the MAV lander (which has a longer arm to transfer tube from the heli, or just next to it, into the sample return container.

I think the concept is viable, with multiple helis most of the real and/or perceived risks associated with those vehicles are mitigated.

[mcaplinger]

I think the concept is viable...

I just hope the engineers are not being overly optimistic. "Just adding an arm and some wheels" sounds like it could easily morph into a mass of ripple effects, and MSR is not on such firm footing at this point that it can afford a lengthy diversion.

And the heli team may find being mission-critical instead of a technology demonstrator not to their liking (ask me how I know.)

[mcaplinger]

NASA will host a media teleconference at 11 a.m. EDT (8 a.m. PDT) on Wednesday, July 27, to discuss the architecture for its Mars Sample Return campaign.

NASA and the ESA (European Space Agency) recently held a systems requirement review as part of the Mars Sample Return campaign’s conceptual design phase – a phase when the architecture is refined and solidified. The briefing will present the architecture proposal that is expected to be finalized in September 2022.

https://mars.nasa.gov/news/9229/nasa-esa-to...return-mission/

[stevesliva]

And the heli team may find being mission-critical instead of a technology demonstrator not to their liking (ask me how I know.)

I thought it was implied that they'll somewhat bank on Perseverance itself as the backup, though I'm now thinking that would preclude dropping tubes anywhere but within reach of the MSL lander's arm. So caches would depend on the helos.

[mcaplinger]

I thought it was implied that they'll somewhat bank on Perseverance itself as the backup...

Perhaps they will grit their teeth and do this, though M2020 will be way outside the warranty then. But I find it hard to believe that the near-total lack of standard mission assurance stuff (all the parts in Ingenuity were COTS, no rad-hard anything, no MIL-STD-883 anything, as far as I know) will pass muster here. But I could be wrong, we'll see.

[Explorer1]

Although it will probably be addressed at the press conference, just considering how far even tiny Ingenuity must remain from Perseverance to ensure the safety of the hardware, either the arm on the sample return lander is going to have to be very long and flexible to be able to retrieve the tubes from under the helicopter, or else there will be much more confidence in the precise control and landing of the helicopter(s). No rapidly spinning rotors are allowed near terrestrial launch sites, last time I checked....

Comedy option: the tubes are dropped in mid-air to fall within somewhere reach of the arm, and then the helicopter lands a safe distance away to recharge for its next sortie. We know they will have to take a much stronger impact a few years later, and drones dropping heavy objects is a long proven technology on Earth.

[djellison]

......just considering how far even tiny Ingenuity must remain from Perseverance.......

The fetch rovers being described also have wheels to drive around a bit as well.

[bobik]

In this presentation about ESA's perspective on exploring Mars, held on the 7th July, the future of SFR was already put under discussion, the Sample Fetching Helicopter (SFH) idea was talked about, and some interesting tidbits about the Sample Transfer Arm (STA) development were given.

[Explorer1]

Briefing started now. Looks like the architecture has been revised, based on 'new studies and recent achievements'. Relying on Perseverance to bring the samples to the MAV, with an ESA arm, and 2(!) helicopters as a backup! So looks like 1 launch (excluding the ERO)

Pity the fetch rover is gone, but hey, whatever works!

Looks like the arm will directly retrieve them from Perseverance, somehow.

Illustration and press release here: https://www.nasa.gov/press-release/nasa-wil...o-earth-in-2033

Looks like each helicopter will have wheels to manouevre on the ground, both to/from the tubes and the lander.

[mcaplinger]

Kind of an odd statement in the press release:

This refined concept for the Mars Sample Return campaign was presented to the delegates from the 22 participating states of Europe’s space exploration program, Terrae Novae, in May. At their next meeting in September, the states will consider the discontinuation of the development of the Sample Fetch Rover.

Not sure what "consider" means in this context.

[bobik]

The riddle of the cancelled press briefing last week wasn't solved, was it?

[mcaplinger]

Looks like the arm will directly retrieve them from Perseverance, somehow.

Rover just rolls up to the front of the lander in reach of the arm and barfs the samples out of the caching system onto the ground where they can be picked up, would be my guess. Unless there is some better mode that the caching system supports, I'm too lazy to find the as-flown description of the system right now and don't recall for sure.

[Explorer1]

Judging from the (admittedly low-quality) image in the release, the end does not exactly look like it has 'fingers'. I expect that we will have more details to come in the coming months, with further reviews...

[mcaplinger]

Judging from the (admittedly low-quality) image in the release, the end does not exactly look like it has 'fingers'. I expect that we will have more details to come in the coming months, with further reviews...

As far as I can tell from "Mars 2020 Rover Adaptive Caching Assembly: Caching Martian Samples for Potential Earth Return" https://trs.jpl.nasa.gov/bitstream/handle/2...252320-1515.pdf all the rover can do is drop a sample out of the caching system. Maybe the ESA arm can grapple it or catch it before it hits the surface?