NASA Mars Exploration Rover Updates 25 Feb 2004
Spirit Status for sol 52 – Spirit Looks Back at Earth – posted Feb. 25, 4:30 pm PST
On sol 52, which ended at 3:54 p.m. PST, February 25, rover
engineers drove Spirit the short 4-meter (13.1 feet) drive to
"Middle Ground" after finishing observations with the miniature
thermal emission and Moessbauer spectrometers. Several stutter
steps that would have put Spirit at the exact target location were
not executed because they were programmed with built-in
safeties. The rover detected slight hazards and stopped within its
constraints. The final steps will be executed next sol.
Waking up to Foreigner’s "Cold as Ice," Spirit’s first job of the sol
was to warm up its arm that was significantly colder than
yestersol due to the rover’s orientation to the northwest. The
engineering team also took a moment to wave to Spirit as its
panoramic camera faced and imaged Earth. Spirit
will remain at "Middle Ground" for the next several sols and
continue observing targets with its spectrometers and microscopic
imager. Plans also call for high-resolution images of rocks and an
examination of the soil.
Opportunity Status for sol 31 – Opportunity Gets an Attitude Adjustment – posted Feb. 25, 10:15 am PST
On sol 31, which ended at 3:36 a.m. Wednesday, February 25,
Opportunity awoke to "Rock Around the Clock" by Bill Haley and
his Comets. At 1:00 a.m. Local Solar Time, Opportunity sent data
to Earth via the Mars Global Surveyor orbiter and then sent
another whopping 145.6 megabits of data at 3:30 a.m. Local Solar
Time via the Mars Odyssey orbiter.
During the morning hours, Opportunity collected data with the
alpha particle X-ray spectrometer for five hours and took
measurements with its miniature thermal emission spectrometer
from inside its newly formed hole that was created on sol 30 by
the rock abrasion tool. Later, Opportunity retracted and closed the
door of the alpha particle X-ray spectrometer and swapped the
Moessbauer spectrometer into the hole made by the abrasion tool
for a leisurely 24-hour observation.
Opportunity also updated its "attitude knowledge," which
fine-tunes the rover’s information about its exact location and
position on Mars. Updating the attitude knowledge allows the
rover to more accurately point the high gain antenna toward Earth,
which increases the communications capabilities. The attitude
adjustment also enables scientists and engineers to point
instruments onboard Opportunity more precisely at targets of
interest, such as particular rocks and patches of soil. To adjust the
attitude knowledge, engineers have the rover turn the panoramic
camera to the Sun and watch the Sun travel across the sky for 15
minutes. The rover is then smart enough to take the Sun
movement data collected from the panoramic camera to calculate
its own location in the universe..on Mars. The rover gathers
attitude knowledge errors over time as it drives and uses the
robotic arm extensively, but it only needs an attitude adjustment
about once a week or after driving long distances.
Around 12:15 pm Local Solar Time, Opportunity went to sleep to
recharge its batteries from its strenuous rock abrasion tool
activities on sol 30, but reawakened briefly at 4 p.m. Local Solar
Time and again in the evening to send data to Earth via additional
overflights by the Mars Global Surveyor and Odyssey orbiters.
The plan for sol 32, which ends at 4:15 a.m. Thursday, February
26, is to take another unique set of Moessbauer measurements to
look at the rover-created hole in a different spectrum. The goal is
to then crawl slightly forward on sol 33 to position Opportunity to
use the rock abrasion tool on the upper target of the El
Capitan/McKittrick area.
