Once again the drive went well and we planned another drive on Sol 41. The
terrain is relatively featureless in this area, so we are focusing imaging
plans on distant targets. We are on a relatively high plateau so the views
toward the rim of Gale crater are better than they were from the landing
site. The path to Glenelg is mostly (slightly) downhill from here, so the
distant views are as good as they will get for a while.

The amount of time we have to plan each sol's activities is a bit shorter
than usual these days due to unusually long delays in relaying the data
from MSL through the Mars orbiters. So we are not able to plan as many
scientific observations, but are still able to drive each sol. ChemCam is
working well and returning good data again.

Once again, the drive went well, and we are 20 meters closer to Glenelg,
our near-term goal. The terrain surrounding the rover at the end of the
Sol 39 drive is not as interesting as the previous location, so we didn't
plan many observations besides those needed to support drive planning. But
the plan included some ChemCam observations, as the instrument team is now
ready to resume tactical planning. Hooray! The Sol 40 drive will be a bit
longer, over 30 meters, and should get us to a low ridge that will give us
a better view of the terrain ahead.

I was reminded again today how diverse the MSL team is. Okay, white males
make up the majority of the team, but women serve in many of the most
important roles, including Mission Manager, Deputy Project Scientist,
Tactical Uplink Lead (mostly women), and Science Theme Lead. Most
impressive is the number of team members from foreign countries, including
Spain, Russia, and France, for whom English is a second (or third)
language. They are required to understand all of the team discussions and
respond to questions in English, despite the highly technical nature of the
subject matter. Some of the engineering jargon is unfamiliar to many of us
who are native English speakers! For example, "IPE supra-tactical reported
replacement of the MOB backbone in tosol's APAM and deconfliction of the
margin after the mobility block." Hard enough to understand when English
is your first language--I'm really impressed by the foreign nationals'
ability to do such a good job in these conditions.

The drive went as planned, and left MSL next to a
nice outcrop During the drive the DAN instrument monitored neutrons coming up from the
subsurface and noticed significant variations along the way. It's not
known (at least to me) what causes these variations, but possibilities
include hydrated minerals, water ice (unlikely?), and density variations.
Another drive is planned for Sol 39 (about 20 meters this time), so a bunch
of images of the outcrop were planned before the drive. Unfortunately, we
aren't expecting to get much data through the orbiters tomorrow, so we
probably won't see these images for a while. Worse, we may not get enough
Navcam images after the Sol 39 drive to plan more observations in the new
location. The amount of data that can be relayed to the orbiters depends
on how high in the sky they pass over MSL, which varies a lot day to day.
In addition the Mars Reconnaissance Orbiter (MRO) is turning instruments
back on, which may interfere with MSL radio communications. Therefore,
telemetry rates are set low to ensure that we get at least some data while
characterizing the radio link with the instruments turned on. Most of
MRO's instruments were off during MSL landing to maximize the amount of
data that could be relayed from MSL. The instruments are resuming
scientific data collection after the hiatus for MSL.

With the successful execution of the last of the MSL arm checkout
activities , the characterization phase is complete! Many first-time activities still lie ahead (like drilling, scooping, and delivering samples to the
mineralogy and organic chemistry instruments), but the major capabilities
of the rover have been demonstrated. So after spending over a week in the
same place to complete the characterization, the Sol 38 plan included a
32-meter drive toward the east. The near-term goal is "Glenelg," still a
few hundred meters away
few hundred meters away . Images taken from orbit show that Glenelg is at the junction of 3 different
terrain types, the brightest of which may be ancient lakebed sediments. It
will take several sols to get to Glenelg, and we are hoping that the
driving goes well.

The ChemCam instrument was confirmed to be safe, but will not be used again
until Friday to give the ChemCam team a chance to rest and regroup. The
team met at the end of the planning day (7:30 PDT) to review the data
received so far and to plan the next steps. By the time of this meeting I
had been up all night, so I was pretty tired but it was a good meeting, and
kept me off the freeway until rush hour traffic cleared a bit.

It was my last shift as MAHLI/MARDI Payload Uplink Lead this week, and
ended up being fairly busy because the MSL science team requested more
MARDI images at various times of day to see how useful the images are under
different illumination conditions. We were also able to plan one image at
exactly the same time of day as one taken on Sol 32, to look for changes on
the surface due to winds. So I sat down with one of the rover planners to
look at how much the rover shadows the MARDI field of view at various times
of day. I always enjoy working with the rover planners because their
visualization tools are so COOL. They allow a model of the rover to be
placed on the 3-D terrain derived from stereo images and illuminated by a
fake sun. This model showed that the MARDI images would be partly shadowed
until 15:00, when only a corner of the images would be shadowed by the left
front rover wheel. So we planned a couple images in the late afternoon and
one earlier to span the range of illumination. Based on the preliminary
results of the compression testing I've been doing, I recommended more
compression of the fully-illuminated images, to reduce data volume without
sacrificing image quality. Details in shadows are more difficult to
preserve when the image is compressed, so we left the partly-shadowed image
at the default (minimal) compression.

Although I'm not staffed in a tactical role for a few days, I plan to stay
involved in tactical operations on Mars time, as shifting between Earth and
Mars time is difficult these days.

See raw images

The checkout of the MSL arm continues to go well: The Alpha Particle X-ray
Spectrometer returned its first data, of its calibration target on the side
of the rover. I was busy last night planning a bunch of MAHLI images to be
taken as part of the verification that the arm can be accurately placed
over the inlets for Chemin and SAM, the mineralogy and organic chemistry
instruments. I also helped plan Mastcam "sky flats," images of the sky to
be used in measuring the variations in response of the camera detectors
across their field of view. Taking pictures of the sky is one of the
techniques used by astronomers to "flat field" their instruments, typically
during evening twilight before a night of observing through a telescope.
It's a bit more difficult to use this technique for the MSL cameras, as
their fields of view are much larger than typical observatory instruments,
and more of the variations in brightness across the sky are visible. To
allow the shape of the sky brightness variations to be measured, we planned
a small mosaic of images around a central image that will be corrected for
these variations. Right after these were approved for the Sol 36 plan, I
remembered that the Navcams can be calibrated using the Mastcam
observations, so I asked if they could be included at the last minute.
Fortunately, the leaders of the planning team agreed to add them!

"Mars time" continues to shift relative to PDT, so by the time I left JPL
it was daylight, and I got stuck in morning rush hour traffic on the way to
my apartment in Pasadena. Fortunately, I won't have this problem for long,
as the MSL work day will keep shifting later. Tonight my shift starts just
before midnight and ends at 10:15 AM PDT. By then the traffic should have
cleared somewhat...

There were more cheers and applause when MAHLI images of the belly of the
rover were displayed . The
camera, which can focus at distances from 2 cm to infinity, is working
perfectly! It also took pictures of its calibration target , which
includes a 1909 Lincoln penny . The arm
checkout also went well, leaving the Alpha Particle X-ray Spectrometer
(APXS) facing its calibration target for a long integration. Unfortunately, ChemCam suffered a command error on Sol 34 and
was shut down by the rover computer. This also prevented the rest of the
planned remote sensing observations from being acquired that sol, and the
remote sensing mast (RSM) from being used on Sol 35. So the Sol 35 plan
was rather simple, including more APXS integration on its calibration
target followed by retraction of the arm. Even though we couldn't use the
RSM, we could still plan a test of Mastcam's video capability, as it
doesn't matter where the cameras are pointed for this test. We are all
hoping that recovery from the ChemCam error will be rapid, and that we will
be able to use it and the rest of the instruments on the RSM tomorrow.

Over a month into the mission, there are still cheers at JPL when
first-time activities are completed successfully. Last night, the latest
successes included the first Chemin X-ray diffraction pattern (of an empty
sample cell), and the first MAHLI image with its dust cover open . Previous
images through MAHLI's dust cover window had much lower contrast , probably
because dust settled onto it during MSL's landing. So there was some
concern that the dust raised by the landing rockets had gotten under the
cover onto MAHLI's optics. The beautifully clear MAHLI image received
yesterday showed that any such dust contamination was insignificant, and
that the camera is ready to go. So the Sol 34 plan included many MAHLI
images of calibration and other targets on the rover, as part of a thorough
checkout of the arm pointing. As MAHLI/MARDI Payload Uplink Lead for the
first shift last night, I had a lot of MAHLI command sequences to keep
track of, but it wasn't very difficult because the arm checkout had already
been run on the MSL testbed (nearly identical rover in a lab at JPL) and
the sequences built and tested. The checkout includes a mosaic of MAHLI
images looking under the rover, to look for any signs of damage incurred
during landing. I left JPL when my shift was over at 5 AM, and got enough
sleep this morning that I think I have made the transition onto Mars time.

I arrived in Pasadena at about 10 PM last night, and went straight to
JPL to catch up with the MSL team and start my transition to Mars
time. My next shift starts at 9:15 PM tonight. I walked in during a
science team meeting regarding "data management" which sounds boring
but is very important to the team. In addition to the rover
computer's ability to adjust the priority of various data products to
be sent to Earth, each of the color cameras includes an 8 gigabyte
buffer for storing raw images. So we can acquire panoramic mosaics of
many images and return only small "thumbnail" versions of each image
while storing the full-resolution images in the camera buffer. Once
we have looked at the thumbnails, we can return just the full images
of most interest. Obviously this is a nice capability to have, but it
means we have to do more work to keep track of the data onboard the
rover.

I stayed through the end of the SOWG meeting, and left JPL around 3 AM
this morning. On my way out, I talked with Roger Wiens, the PI of
ChemCam. His instrument has been working well, and he wanted to
discuss the results of the RMI compression testing I mentioned last
week. We were both too tired to have the conversation then, and
agreed to talk later. But I summarized my conclusion that, while the
test data in hand are useful in determining the optimum compression
parameters, more test data are needed. Meanwhile, the focus of
near-term rover activities will be checkout of the arm .

I was planning to stay on "Mars time" while in Flagstaff this week, but it would have meant less time with my family, so I haven't been sleeping very late. This has allowed me to call in to Mars Exploration Rover planning meetings at 9 AM and catch up with what Opportunity has been doing. After over 8 years roving on Mars, Opportunity is exploring the rim of a 22-km diameter crater that shows evidence from orbit of clay minerals that were probably formed during a more Earth-like period in Martian history. I'm the science lead for the Microscopic Imager (MI), the close-up camera (like a geologist's hand lens) on the end of Opportunity's instrument arm. The rover is now investigating an outcrop that is unlike any we have seen before. The MI just acquired a 2x2 mosaic of images of this outcrop . The abundant spherules seen in these images are generally smaller than the hematite concretions found on the Meridiani plains by Opportunity, and broken ones show more internal structure than the concretions. So they don't appear to be the same kind of concretions, but more data are needed to understand this rock. Today we are finalizing a plan that includes brushing the dust off of this outcrop, taking 4 more MI images to confirm that the brushing worked, and placing the Alpha Particle X-ray Spectrometer on the brushed spot to get elemental chemical information. There are other interesting outcrops in the vicinity of the rover, including some brighter ones that may contain more clay.

So the Opportunity mission is going very well, and I hope to find some time to keep up with it while I'm working on MSL in Pasadena. I will be working graveyard shift, but could drop in on Opportunity planning meetings after my MSL shift if I'm not exhausted. With so much rover activity on Mars these days, it will be difficult to sleep!