Mars Exploration Rovers Update - February 16, 2007

SPIRIT UPDATE: Spirit Perfects the Art of Driving on Five Wheels -
sol 1104-1112, February 16, 2007:

Rover drivers have now refined their techniques for maneuvering
on only five wheels. All of Spirit’s drives during the past week
ended within centimeters (inches) of the targeted endpoint.
Spirit is healthy and has arrived at the rock outcrop known as
“Bellingshausen” on the way back to “Home Plate.”

On Feb. 10, 2007, the rover’s 1,104th Martian day, or sol, of
exploration, Spirit experienced a warm reset, during which the
rover’s computer rebooted and the rover went into auto mode,
canceling activities for the weekend and awaiting instructions
from Earth. This is the third time Spirit has experienced this
anomaly; Spirit’s twin, Opportunity, has experienced it twice.
The anomaly is attributed to a well-known condition in the flight
software. The rover’s handlers sent new commands that activated
the master sequence of activities for sol 1107 (Feb. 13, 2007).

During scientific studies of targets known as “Mount Darwin”
and “Puenta Arenas” in soil disturbed by the rover’s tracks,
Spirit’s handlers noticed positioning errors in the placement
of instruments on the rover’s robotic arm. In response, they
scheduled diagnostic tests for sol 1110 (Feb. 16, 2007). This
left the team with a tough decision: remain at Bellingshausen
during the long President’s Day holiday weekend or head toward
Home Plate with a day of driving on sol 1114 (Feb. 20, 2007).

Tau measurements of atmospheric dust levels were 0.6; while
solar power levels were 312 watt-hours (a watt-hour is the amount

Sol-by-sol summary:

Except for the sols spent in auto mode, Spirit made daily
that included measuring atmospheric opacity caused by dust with
the panoramic camera, scanning the sky for clouds with the navigation
camera, and surveying the sky and ground with the miniature
thermal emission spectrometer. Spirit also conducted the following

Sol 1104 (Feb. 10, 2007): Spirit went into auto mode.

Sol 1105: Spirit remained in auto mode.

Sol 1106: Spirit remained in auto mode.

Sol 1107: Spirit drove to the Bellingshausen outcrop.

Sol 1108: Spirit acquired panoramic camera images of Bellingshausen
and navigation camera movie frames in search of clouds.

Sol 1109: Spirit turned and approached a rock target known as
“Fabian” and acquired stereo images following the drive using
the navigation camera. The rover also acquired images with the
panoramic camera.

Sol 1110: Plans called for a “rover tai-chi,” which involves
taking images of the contact ring of the Moessbauer spectrometer
with the front hazard avoidance camera before placing the instrument
on a target, and for acquiring panoramic camera images of

Sol 1111: Planned activities included collecting data on targets
known as “Amhor,” “Bantoom,” “Dusor,” “Ghasta,” and “Gooli”
with the miniature thermal emission spectrometer.

Sol 1112 (Feb. 18, 2007): Planned activities included collecting
data on targets known as “Horz,” “Hastor,” and “Invak” with
the miniature thermal emission spectrometer.


As of sol 1109 (Feb. 15, 2007), Spirit’s total odometry was
6,965 meters (4.3 miles).

OPPORTUNITY UPDATE: Opportunity Flips 10 Kilometers and Tests
New Drive Software - sol 1077-1083, February 09, 2007:

Opportunity has completed a remote sensing campaign at “Cape
Desire” and is on the move to the next promontory, called “Cabo
Corrientes.” Opportunity’s odometer rolled past 10 kilometers
(6.2 miles) during the 50.51-meter (166 feet) drive on sol 1080.
By contrast, the NASA Level 1 requirements for the mission called
for achieving at least 600 meters (1,969 feet) with one rover,
and the mission design requirement was for 1,000 meters (3,281
feet). This is another significant milestone for Opportunity,
and yet another testimony to the outstanding work done by the
development and operations teams.

Sol-by-sol summary:

Each sol, the panoramic camera assesses atmospheric opacity
(“tau”) at the beginning of the sol’s sequence of activities
and again before the afternoon Mars Odyssey pass. The miniature
thermal emission spectrometer scans sky and ground during the
Odyssey pass. That instrument also observes sky and ground each
morning as part of the preceding sol’s activity plan, just prior
to Spirit beginning the current sol’s sequence. In addition
to these regular activities, Opportunity also completed the

Sol 1077: Opportunity conducted panoramic camera 13-filter targeting
on “Cabo Anonimo.” The rover then used its miniature thermal
emission spectrometer to stare at: rover tracks, at scuffed
soil, at the area near the tracks and at Cabo Anonimo. The navigation
camera took images to support the work by the miniature thermal
emission spectrometer on and near the tracks. The panoramic
camera also did a 13-filter examination of Cabo Corrientes.
After the Odyssey pass, the rover conducted an argon experiment
during six hours of collecting data with the alpha particle
X-ray spectrometer.

Sol 1078: Opportunity drove 42.81 meters (140 feet) away from
Cape Desire and then performed an update of its orientation.
Post-drive imaging included navigation and panoramic camera
mosaics. There was no science activity around the afternoon
Odyssey pass on this sol because the team decided to use the
energy to support an overnight UHF pass.

Sol 1079: The miniature thermal emission spectrometer completed
a seven-point sky and ground analysis, the navigation camera
looked for clouds, and then the rover completed two miniature
thermal emission spectrometer sky and ground stares.

Sol 1080: The rover drove 50.51 meters (166 feet), then collected
images for mosaics with the navigation and panoramic cameras.
There was another morning UHF pass in the 1080 plan, so no science
activity was conducted around the afternoon Odyssey pass.

Sol 1081: In the morning of this sol, a panoramic camera horizon
survey was conducted. The navigation camera looked for clouds
and then the miniature thermal emission spectrometer conducted
a seven-point analysis of sky and ground. During the afternoon
Odyssey pass, that instrument completed a five-point sky and
ground analysis.

Sol 1082: The plan included a checkout of new autonomous navigation
software during a drive toward Cabo Corrientes. Planned imaging
after the drive included mosaics by the navigation and panoramic
cameras. The rover’s panoramic camera was instructed to view
the Martian moon Phobos.

Sol 1083 (Feb. 9, 2007): The plan for this sol calls for the
panoramic camera to have a look at the sky in the morning. The
navigation camera will then look for clouds and the miniature
thermal emission spectrometer will conduct a seven-point sky
and ground analysis. In the afternoon, the rover will have another
chance to see Phobos in the sky.


As of sol 1080 (Feb. 6, 2007), Opportunity’s total odometry
was 10,023.19 meters (6.23 miles).