26 August 2018
The big question coming into today was whether to re-do the SAM analysis or not. Now that the drill is being operated with the feed immobile in the extended position, the portions (amount of drill tailings) that are delivered to CheMin and SAM are less accurate than before. Duluth was the only previous drill attempt to reach sampling depth with the feed immobile. In that case several attempts were made to deliver proper portions to the in-situ instrument funnels.
The accompanying image shows the positions of the SAM inlets on the rover deck, with the covers closed. The rover team seems to have learned quite quickly how to get the portions to these instruments, and this morning we learned that SAM completed a successful analysis. The other part of the decision was whether to repeat SAM‘s analysis with different parameters, but the team decided not to do so at this time, so now we can continue with the drill analysis sequence. That will include dumping the rest of the material so we can see how much was left in the drill chambers. The operation will be carried out using two dozen separate portion drop-off sequences with Mastcam images in between to check how much material comes out. I just watched an animated video of the sequence and it looks pretty cool. The arm swings down near the ground for each drop-off, then moves out of the way, and the mast points Mastcam to take an image. Then the mast turns away-to avoid any possible dust-while the arm swings down for the next drop off. Every drop-off is done in a slightly different location on rock surfaces, some being spaced 7 mm away from each other around a circle. Each little portion gets imaged.
Other activities planned for tosol include ChemCam bedrock target ‘Papa Little’ and another ChemCam raster down the drill hole, with accompanying Mastcam documentation. There will also be half a dozen MARDI change-detection images spaced throughout the day. DAN, REMS, and RAD will continue taking data.
Written by Roger Wiens, Geochemist at Los Alamos National Laboratory