I was MAHLI uplink lead again for Sol 282, and helped plan images of the SAM and CheMin sample inlets to verify that samples were delivered properly. The plan also included sample dropoff to CheMin and overnight analysis. It's nice to see that the updates to the MAHLI "self portrait" of the rover that I helped plan on Sol 270 have been incorporated

The drilling at "Cumberland" went perfectly . The MAHLI images that we planned for Sol 279 came out well . So the plan for Sol 281 includes sieving of the sample and feeding some of it to SAM. This will happen late in the afternoon, when winds are expected to be low, to avoid loosing some of the sample during dropoff to SAM. SAM will then start analyzing the sample overnight.

I was MAHLI uplink lead today, planning 3 sols to get us through the weekend. It was a busy day--lots of MAHLI images were planned, both before and after drilling the Cumberland target. A SAM measurement of the atmosphere and SAM "preconditioning" in anticipation of the second drill sample analysis were also plan, so there wasn't much room for other observations. If all goes well, the sample will be analyzed next week.

Because the critical data from yesterday's plan won't be received until around noon Pacific time, MSL tactical planning starts later than usual today. Even though the MSL project made the transition to "Earth time" planning months ago, the schedule is still allowed to shift a few hours when necessary. Meanwhile, Opportunity, on the other side of Mars, sent data in the middle of the night and will receive commands in the afternoon Pacific time. So Opportunity planning is starting earlier than usual (7 AM PDT yesterday). I'm MAHLI uplink lead for MSL again today, but wanted to call in to the Opportunity kickoff meeting this morning to hear the latest. I was rewarded with the news that Opportunity now holds second place among extraterrestrial rovers for total distance traversed, just passing the Apollo 17 lunar rover's record of 35.74 km. First place is still held by the Russian Lunokhod 2 rover, which drove 37 km on the lunar surface. It may be a long work day for me, but operating 2 rovers on Mars is, as they say, "a nice problem to have."

It's good to see that the activities we planned over the weekend went well--the rover is now in position to drill the target "Cumberland." I'm MAHLI payload uplink lead for Sol 275, and helped plan MAHLI images of the potential drill target. These images are intended to confirm that the target is suitable for drilling.

Today we planned 3 sols (271-273) in one day for the first time on MSL. I was nervous about leading the science team as SOWG Chair through this challenging planning day, but it went smoothly. In fact, planning Sol 270 yesterday was more hectic, in part because of the variety of activities we squeezed into the plan, including hundreds of MAHLI images and lots of arm motion. There were a number of high-priority science observations we wanted to accomplish before driving away from the first drill hole, and lots of pressure to fit them into the Sol 270 plan so that we can move on to the next drill target, called Cumberland . The Sol 272 plan includes a bump (short drive) designed to move the rover within 1 meter of "Cumberland" and all the imaging needed to plan another bump that will position the rover for drilling.

I was SOWG Chair today for the first time since the conjunction stand-down. A new version of flight software has been installed on the rover, and many of the Sol 269 activities focused on acquiring images needed to evaluate the precision of camera pointing on the "B" computer running the new software. We also planned Mastcam observations of nearby targets of interest. All is going well, but there is still more analysis to be done before the full capabilities of the rover can be used.

Both Mars rovers survived conjunction, when they could not be reliably commanded for most of April. Opportunity had some computer issues, but is now back under sequence control and a short drive was planned today. MSL (Curiosity) is healthy and the first post-conjunction tactical planning is today. Before resuming full science operations, a new version of flight software is being loaded onto MSL. It should take the rest of this week to confirm that the software is properly installed.

For most of April, while Mars is behind the Sun as seen from Earth, no commands are being sent to MSL. Before the start of the solar conjunction stand-down, the rover was programmed to acquire radiation and weather data every day. The Sun interferes with radio waves that pass close to it, but we have received a bit of data anyway, enough to know that the rover is healthy and running the command sequences as planned.

I'm not scheduled in any tactical operations roles this week, but have
been calling into planning meetings for both MSL (Curiosity) and MER
(Opportunity). The rovers and other Mars spacecraft are preparing for
the upcoming "superior conjunction" of Mars, when the planet will pass
behind the Sun as seen from Earth. For a couple weeks around
conjunction, it is difficult (or impossible) to communicate with the
spacecraft because radio waves are disrupted by plasma in the Sun's
atmosphere. So command sequences have been prepared to get the
spacecraft through this period safely, without much activity. This
week is our last chance to plan additional observations before the
conjunction plan kicks in, so we are finishing up the highest-priority
science activities on both rovers. On MSL, these include APXS,
Mastcam and ChemCam measurements of the first drill sample after it
was dumped out of CHIMRA. For MER, we have selected in interested
rock target to place the APXS, in order to acquire lots of good data
during conjunction.