Mars Exploration Rover Update - August 31, 2004

http://marsrovers.jpl.nasa.gov/mission/status.html

SPIRIT UPDATE: Spirit has been etching into 'Ebenezer' - sol 219-231,
August 31, 2004

During sols 219 through 223, Spirit completed science observations at
the "Clovis" rock outcrop. So Spirit packed up and slowly moved on.
Winter is approaching and temperatures continue to drop. Power is always
a major concern as available energy fluctuates between 300 and 400
watt-hours per sol, but Spirit continues the quest, climbing ever higher
into the Columbia Hills. Spirit has climbed more than 13 meters (43
feet) in elevation from Hank's Hollow, at the base of Columbia Hills,
but currently is at an elevation of 37 meters (121 feet) above its
landing site on the plains of Gusev Crater!

On sol 224, operators became concerned that Spirit's batteries might be
entering a very low state of charge, so Spirit shut down to charge the
batteries.

Sol 225 was truly a mega-activity sol. Spirit awoke at 11:20 a.m., Gusev
local solar time and stayed awake well past the afternoon communication
session with NASA's Mars Odyssey orbiter without taking a nap. Spirit
hasn't done that in a long time. The rover extended its arm and used its
rock abrasion tool to brush seven circular patches on Clovis. After the
first five brushings, the arm was moved out of the way and an image was
taken of the circles. These five brushing circles resemble the Olympic
rings.

After completing the brushing, Spirit performed a 30-minute reading with
its alpha particle X-ray spectrometer, imaged the seven rings using its
microscopic imager, stowed its arm and drove one meter (three feet)
backward, farther off of the Clovis outcrop. Spirit's day was far from
over. The rover performed post-drive observations with its navigation
camera, observations with its miniature thermal emission spectrometer
concurrent with the afternoon Odyssey pass, and panoramic camera
observations before shutting down. Another gold medal performance for
Spirit!

Total odometry after sol 225 was 3,605 meters (2.24 miles), a Mars record.

From sols 226-229, Spirit stopped at a rock dubbed "Ebenezer" for
several sols of intense science. Ebenezer is roughly 8 meters (26 feet)
from Clovis.

While at Ebenezer, Spirit was facing south of east, with its nose
pitched up 21 degrees. This orientation was very favorable from a power
perspective since the sun tracks to the north. Spirit's daily solar
energy input increased about 10 percent as a result. Spirit also had a
great view of the Gusev plain from this location.

On Sol 230, Spirit used the rock abrasion tool to brush a target on
Ebenezer and took an overnight alpha particle X-ray spectrometer reading
on the brushed area. On Sol 231, which ended on Aug. 27, the abrasion
tool ground for two hours into the same spot it had brushed. An alpha
particle X-ray spectrometer reading in the resulting hole began the
morning of Sol 232.

Over the next few sols, the plan is for Spirit to drive to its next
target, which is yet to be determined.