Pebbles Before Mountains – NASA Mars

NASA’s Mars 2020 mission team is working methodically and comprehensively, making good progress in understanding the best path forward to remove unwanted pebbles from a persistent circle. Over the previous weekend, and earlier this week, operational sequences were developed and tested to remove these rock-hard intruders.

After the ground trials were completed, we began implementing our mitigation strategy on Mars. On January 12th we did a detailed image survey under Perseverance. This was done so that we would have a good idea of ​​the rocks and pebbles already below before we would join them in the not too distant future.

With this initial imaging under the hull, the team set out to maneuver our robotic arm that I never imagined we’d perform – ever. Simply put, we are returning the remaining contents of sample Tube 261 (our newest beloved rock sample) to its home planet. Although this scenario was never designed or planned prior to launch, unloading a core from an open tube turned out to be a fairly straightforward process (at least during ground testing). We sent out commands yesterday, and later in the day the rover’s robotic arm will simply point the open end of the sample tube toward the surface of Mars and let gravity do the rest.

I imagine your next question is, “Why are you throwing away the contents of the sample tube?” The answer is that, at the moment, we’re not sure how long the excavated rocks will last in Tube 261. And while this rock will never appear on my holiday card list, the science team seems to really like it. So if our plans go well with the gravel mitigation (see below), we might very well try the “problem” (the rock from which this sample was taken) again.

Which brings me to the next steps in our gravel mitigation strategy: We send the commands to the rover later today, and tell it to do two rotation tests on the bit carousel. These tests (the first, a small cycle; the second, larger) will be carried out this weekend. Our expectation is that these courses – and any subsequent pebble movement – will help guide our team, providing them with the necessary information on how to move forward. However, to be precise, we also require the rover to take a second set of photos under the hull, just in case one or more pebbles come out.

We expect data and images from these two spin tests to be sent back to Earth by next Tuesday, January 18th. From there, we will analyze and improve our plans. If I had to tweak it, I’d appreciate we’d be at our current location another week or so – or even more if we decided to re-sample Issole.

So there you have it. The persistence team is exploring every aspect of the problem to ensure that we not only get rid of this rock debris but also prevent a similar occurrence during future sampling. Basically, we don’t leave any rock unturned in pursuit of these four pebbles.


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