I'm SOWG Chair again today, planning Sol 465, which includes the first drive since the electrical issue over a week ago. The change in power bus voltage appears to have been caused by an electrical short in the Radioisotope Thermoelectric Generator (RTG), the nuclear power source for the rover. This type of intermittent short has been seen in similar RTGs, including the one on the Cassini spacecraft, which has been orbiting Saturn for years. The rover electronics are designed to operate at variable power supply voltages, so this is not a major problem. In fact, the voltage returned to the normal level late last week, so we are ready to drive again. After some targeted ChemCam and Mastcam observations, a 64-meter drive is planned.
Sol 466-468 Anniversary of Launch (26 November)
MSL launched from Florida two years ago today--I was pretty nervous that day, but the mission has obviously gone extremely well! Planning is restricted this week (results of the drive planned for Sol 465 will not arrive until tonight), so we are planning 3 sols of untargeted remote sensing to get the rover through the Thanksgiving holiday. We crammed a lot of science into the 3-sol plan, including a SAM atmospheric measurement, another CheMin analysis of the drill sample, and several ChemCam and Mastcam observations of the sky and distant targets. We also took this opportunity to perform some instrument maintenance activities. So far, planning is going very smoothly!
There was some concern about tears in the rover wheels, but today we got the go-ahead to drive, with no restrictions on distance or drive mode. The tears in the wheels were expected based on testing, and the wheels are designed to survive such damage without affecting mobility. We are planning 3 sols today to get the rover through the weekend, so it has been a busy day for me as SOWG Chair. On the first sol, MAHLI imaging of the wheels (to monitor the tearing) will be followed by targeted ChemCam and Mastcam observations. The plan for the second sol is dominated by a long drive, including AutoNav. Then we are planning some untargeted remote science on the third sol.
NASA / JPL / MSSS / Damia Bouic
Curiosity's wheels on sol 463: tear in left front wheel
Curiosity took these photos of her wheels with the MAHLI arm-mounted camera on sol 463 (November 24, 2013) A large rip has appeared above the Morse-code holes in the left front wheel. Several smaller punch-holes are visible in it and the middle wheel in this view.
NASA / JPL / MSSS / Emily Lakdawalla
Detail view of Curiosity's left front wheel, sol 463 (November 11, 2013)
Sol 472-473 Watching the Wheels (3 December)
The drive planned for last weekend went well, so another drive is planned for Sol 472, along with targeted remote science and MAHLI imaging of the rover wheels. Such images of the wheels are now planned more frequently, to assess possible changes in the tears in the wheels. While the arm is deployed, contact science is also planned for Sol 472. Planning is still restricted, so we won't be able to drive again until Sol 474, and untargeted remote science is planned for Sol 473. I'm MAHLI/MARDI uplink lead for Sol 473 planning, with not much to do because the normal post-drive MAHLI and MARDI images are already planned for Sol 472.
NASA / JPL / Emily Lakdawalla
Curiosity monitors wheels during a drive, sol 474
On sol 474, Curiosity took a short drive while shooting photos of the wheels with her Navcams and Hazcams. From left to right, the images are: left front wheel from left front Hazcam; right front wheel from right front Hazcam; left front wheel from right Navcam; left middle and rear wheels from right Navcam; and left rear wheel from left rear Navcam. Because the mast is located on the right front corner of the rover, the Navcam is only capable of seeing the wheels on the rover's right side. The Hazcams get partial views of three of the four corner wheels. (The only instrument that can see the right middle and rear wheels is the MAHLI camera on the robotic arm.)
Sol 476-477 Good Time for an Upgrade (6 December)
I'm uplink lead for the Opportunity Microscopic Imager and engineering cameras (Hazcams and Navcams) today, so have not been able to follow MSL planning as closely as usual. Operating two rovers on Mars at the same time is a good problem to have! The MSL weekend plan includes more MAHLI imaging of the rover wheels and a short drive to a location that looks good for dumping and examining the drill sample. If all goes well, most of next week will be spend upgrading the rover flight software. Many of the MSL scientists will be attending the fall meeting of the American Geophysical Union in San Francisco next week, so it's a good time for the software upgrade, which will preclude scientific observations. During the meeting, there will be a press briefing summarizing recent science results.
Last week's flight software upgrade went well, so the Sol 485 plan includes science activities. Specifically, MAHLI images and an APXS integration of a target in front of the rover are intended to characterize the area where the remaining Cumberland drill sample will be dumped. I'm currently at a ChemCam science team meeting, so have not been following rover operations as closely as usual. We were glad to hear that the new version of flight software is installed, as it will make operations easier in many ways.
Sol 487 Dump Pile (18 December)
I'm on my way home from the ChemCam team meeting, so again not involved in MSL tactical operations, but saw that the Sol 487 plan includes dumping the last of the Cumberland drill sample and MAHLI imaging of the dump pile. The sample handling system (CHIMRA) will be cleaned out after holding the sample for months. This will make it much easier to use the arm, as sample management will not be required.
NASA / JPL / MSSS
What's left of Cumberland (sol 486)
On sol 486, Curiosity dumped out the rest of the Cumberland drill powder, which had been stored inside the CHIMRA sample handling mechanism since sol 279. The rover delivered many sieved portions of the Cumberland sample to the SAM and Chemin instruments during the intervening 207 sols, but had to dump it to prepare to use the drill elsewhere. The Cumberland sample's gray color is markedly different from the oxidized-red color of Mars' surface.