The Geology of Jezero Crater, Observations & Findings Options

[vjkane]

A portion of a possible traverse that would examine some really interesting features:

A stated difference between Curiosity and Perseverance is that the former's mission is to explore the diversity of features - i.e., drive to and examine as many interesting features as possible. Percy's mission is to collect a full set of Jezero samples (~15) within one Martian year. In presentations, managers have said that there will be less time exploring interesting features.

[atomoid]

...That large image size is giving my eye-crossing muscles a bit of a workout though...[/quote]

that was just a parellel view, though thats more comfortable to the eye muscles (you just fool your eyes to splay as if to look into the distance past the image) it limits the image width to the distance between your eyes as dependent upon the viewing screen size (unless you fiddle with the zoom of your browser window to compensate). Below is the crosseye version, i left it much larger since its a far easier feat to cross than to splay the eyes..

[ElkGroveDan]

If thats Vesicular basalt then isbit safe to say we havent landed in an area that was aquactic

Like Hawaii?

[serpens]

vjkane, Perseverance has four primary mission objectives which contribute to the key science goals of NASA's total Mars exploration program. The program goals are:
Determine if Mars Ever Supported Life.
Understand the Processes and History of Climate on Mars.
Understand the Origin and Evolution of Mars.
Prepare for Human Exploration.

Primary mission objectives are:
Explore an astrobiologically relevant ancient environment on Mars to decipher its geological processes and history, including the assessment of past habitability.
Assess the biosignature preservation potential and search for potential biosignatures.
Demonstrate significant technical progress towards the future return of scientifically selected, well-documented samples to Earth.
Provide an opportunity for contributed Human Exploration and Operations Mission Directorate or Space Technology Program participation.

The first two primary objectives are not incompatible with sample collection and caching and the samples would be harvested from 'interesting features' with solid geological/geochemical indications. But I suspect that a baseline path is being prepared based on the touchdown location and that they will want to move off the mafic floor unit as fast as possible, possibly collecting an igneous sample along the way.

[vjkane]

vjkane, Perseverance has four primary mission objectives which contribute to the key science goals of NASA's total Mars exploration program. The program goals are:
Determine if Mars Ever Supported Life.
Understand the Processes and History of Climate on Mars.
Understand the Origin and Evolution of Mars.
Prepare for Human Exploration.

Primary mission objectives are:
Explore an astrobiologically relevant ancient environment on Mars to decipher its geological processes and history, including the assessment of past habitability.
Assess the biosignature preservation potential and search for potential biosignatures.
Demonstrate significant technical progress towards the future return of scientifically selected, well-documented samples to Earth.
Provide an opportunity for contributed Human Exploration and Operations Mission Directorate or Space Technology Program participation.

The first two primary objectives are not incompatible with sample collection and caching and the samples would be harvested from 'interesting features' with solid geological/geochemical indications. But I suspect that a baseline path is being prepared based on the touchdown location and that they will want to move off the mafic floor unit as fast as possible, possibly collecting an igneous sample along the way.

Serpens, you are right that exploration is compatible with all those goals. But while Curiosity has taken years to get to where it has, Percy is supposed to make the Jezero crater rim in about one Martian year. That just leaves less time to smell the flowers or zap the rocks.

And then if I remember right, about another Martian year to reach the Midway area, about another year to collect samples there, and then the MSR lander is scheduled to arrive.

[serpens]

I thought the revised schedule was for launch of the retrieval mission in 2028 with the return of the samples in 2033?

[vjkane]

I thought the revised schedule was for launch of the retrieval mission in 2028 with the return of the samples in 2033?

A review team suggested planning to delay the launch but nasa is still going with 2026. Between you and me I’d bet on 2028, but 2026 has 2028 as a backup. There’s no backup to 2028.

[Explorer1]

One of the papers I read (can't find it now) implied that speed is not about finishing before the retrieval mission arrives, but placing enough caches down in case something catastrophic happens years down the road, rendering any samples still inside Perseverance irretrievable. The fetch rover's job is difficult enough as is; no need to make it harder.

[vjkane]

One of the papers I read (can't find it now) implied that speed is not about finishing before the retrieval mission arrives, but placing enough caches down in case something catastrophic happens years down the road, rendering any samples still inside Perseverance irretrievable. The fetch rover's job is difficult enough as is; no need to make it harder.

The current plan is to double collect in Jezero. Half the collection is left on the rim in case Percy has a catastrophic failure on the way to Midway. Ideally, Percy collects new samples in Midway to supplement those retained from Jezero.

There doesn't seem to be a consensus yet on how to deal with samples carried from Jezero or collected in Midway. If they are retained by Percy and it has a catastrophic failure, the fetch rover can't remove them from Percy. If Percy deposits all of them in a cache at Midway and the fetch rover fails, Percy can't pick them up to deliver them to the MAV.

[MahFL]

...Percy can't pick them up to deliver them to the MAV.

I was under the impression once Percy drops the tubes on the ground it cannot pick them back up.

[JRehling]

One solution to this would be to fill about 3/4 (~24) of the sample tubes on the way up to the rim. At the top of the rim, drop ~16 of them, representing the whole trek up the delta, on the ground, and keep ~8 that also represent the trek up the delta. Then pick up ~8 more on the crater rim, and when that is complete, drop all ~16 in one spot.

That leaves you with ~16 representing the delta in one place and ~16 representing both the delta and the crater rim in another place. The return can choose which group of 16 to retrieve. If there were any failure in the return, there's another group of ~16 for a second try. If Perseverance failed after reaching the crater rim, there would be the first set of ~16 for a first and only retrieval attempt.

[HSchirmer]

[HSchirmer]

If they are retained by Percy and it has a catastrophic failure, the fetch rover can't remove them from Percy.

Let me introduce you to 1998 Jeremy Clarkson... https://youtu.be/X7USYfgvIkU?t=28

[vjkane]

One solution to this would be to fill about 3/4 (~24) of the sample tubes on the way up to the rim. At the top of the rim, drop ~16 of them, representing the whole trek up the delta, on the ground, and keep ~8 that also represent the trek up the delta. Then pick up ~8 more on the crater rim, and when that is complete, drop all ~16 in one spot.

That leaves you with ~16 representing the delta in one place and ~16 representing both the delta and the crater rim in another place. The return can choose which group of 16 to retrieve. If there were any failure in the return, there's another group of ~16 for a second try. If Perseverance failed after reaching the crater rim, there would be the first set of ~16 for a first and only retrieval attempt.

Phil Stooke at NASAspaceflight.com posted links to presentations from a recent sampling strategy workshop. Extremely interesting with lots of details on the notional traverses, notional sampling plan, and notional caching strategy

Link to Phil's post

First set of slides

Second set of slides

Third set of slides

These slides are from those presentations and represent a notional sampling strategy.

Attached thumbnail(s)

 

[JRehling]

Thanks for the full background, Van.

It was this pair of adjacent statements from the first set of slides: "Perseverance is likely to create two depots, only one of which will likely be returned. - notionally, one in Jezero Crater and one somewhere on Nili Planum. The Science Team believes that the only way to have the complete collection in a second depot is to 'double sample' critical (all?) samples prior to first depot deployment."

…that I was summarizing with my comment in terms of ~16s and ~8s.