SPIRIT UPDATE: Spirit on Autopilot - sol 239-242, September 09, 2004
Spirit is in safe place to continue daily science observations
automatically throughout the solar conjunction period when engineers and
scientists will be unable to send commands reliably to the rover. An
18-day period began a transition into solar conjunction on sol 241, when
the Sun partially obscured the communications path between Earth and
Mars, making communications sessions unreliable. Engineers were able to
successfully command Spirit on sol 241, and they had partial commanding
success on sol 242.
Engineers will attempt to command Spirit on sol 243 also. From sol 244
through sol 255, sequences already safely on board will perform a set of
science activities on a daily basis. On sols 256 through 258, the last
three days of conjunction, the rover team will attempt normal operations
On sol 242, engineers sent Spirit a set of coordinated commands to use
the miniature thermal emission spectrometer and panoramic camera for
observations of possible future science targets. A new set of 12
conjunction master sequences was also transmitted successfully to
Spirit. This new set of conjunction master sequences will use less
energy than previous sequences.
For the conjunction period, the rover team has placed the Mossbauer
spectrometer on one of the two magnets on the rover deck. Spirit will
activate the Mossbauer instrument every day during conjunction in order
to characterize the dust that has collected on the magnet. However, a
wrinkle has developed in this plan. Before placing the Mossbauer
spectrometer on the magnet, Spirit placed it on the soil in front of its
current location. That soil touch was done to leave a soil impression
that would be studied after conjunction for changes. Images taken after
the touch indicate that Spirit inadvertently picked up some soil and
likely sandwiched that soil onto the magnet with the Mossbauer. It's the
team's first inadvertent sample acquisition!
Engineers and scientists decided to leave the Mossbauer in place on the
magnet and will evaluate the status and effect of the dirt clod after
conjunction. The dirt does not pose any threat to the rover from an
Since Spirit arrived at its solar-conjunction resting place, its science
activities have focused on gathering data from the surrounding area for
use in planning post-conjunction sols. Navigation camera images in
Spirit's drive direction have been used to develop traverse maps. These
maps show areas that allow Spirit to maintain a north-facing tilt; these
areas will provide significantly more solar energy and will therefore be
favored as the team plans the traverse to Spirit's next science target.
During conjunction, Spirit will transmit five-minute "beep" tones, and
engineers will send "No-operation" commands to the rover to characterize
effects that the conjunction has on radio transmissions between Mars and
OPPORTUNITY UPDATE: RAT is Rearin' to Go! - sol 211-214, September 09, 2004
Opportunity is healthy and continuing to explore a rock called "Escher"
on the southwestern slope of "Endurance Crater."
Sol 211: Opportunity awoke from deep sleep at 7 a.m. local solar time.
It re-enabled survival heaters on its miniature thermal emission
spectrometer and re-started a Mossbauer spectrometer examination of a
target called "Kirchner." The rover made observations with its panoramic
camera and its miniature thermal emission spectrometer from about 11
a.m. to 2 p.m. local solar time, focusing on getting thermal inertia
measurement of the dunes at different times of day. A planned tool
change to the alpha particle X-ray spectrometer in the afternoon failed
due to a sequencing error in retracting the Mossbauer spectrometer from
the surface. A conditional sequencing check prevented the overnight
alpha particle X-ray spectrometer integration from occurring as desired
in such fault cases.
Sol 212: A calibration of the rock abrasion tool calibration was
completed successfully. The tool is healthy and ready for action! An
aggressive plan acquired 80 microscopic images of the rock Escher. As
part of the team's efforts to increase operational flexibility, a test
was conducted involving operating the miniature thermal emission
spectrometer in parallel with arm operations. Unfortunately, this
resulted in some corrupted data from the miniature thermal emission
spectrometer due to vibrations as the rover arm moved. The rover used
its Mossbauer spectrometer in the afternoon before going into deep sleep
Sol 213: Opportunity awoke from deep sleep and re-started the Mossbauer
integration. The rover performed some remote sensing during the day and
then changed tools to the alpha particle X-ray spectrometer for an
overnight integration. Later it completed a midnight thermal inertia
observation with the miniature thermal emission spectrometer, which
required an hour of actuator preheating.
Sol 214: Opportunity completed the alpha particle X-ray spectrometer
observation and successfully used the rock abrasion tool to brush clean
two targets on Escher ("EmilNolde" and "Kirchner_RAT"). Then it made
observations with its microscopic imager, hazard-avoidance camera and
panoramic camera. The Mossbauer spectrometer was then positioned on
Kirchner_RAT, where it analyzed the rock's mineral composition until the
rover went into deep sleep overnight. Sol 214 ended on Aug. 31.