[meteorite-list] Mars Exploration Rover Update - October 9-15, 2008

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon, 20 Oct 2008 16:42:03 -0700 (PDT)
Message-ID: <200810202342.QAA23114_at_zagami.jpl.nasa.gov>


SPIRIT UPDATE: Getting Ready to Make the Next Move - sol 1695-1701,
October 09-15, 2008:

In recent weeks, increasing solar power has enabled Spirit to complete
more science activities. Spirit has finished the 360-degree, full-color
view of its winter surroundings, known as the "Bonestell panorama," and
acquired extra frames at super resolution to enhance details in the
imagery. The rover also has documented seasonal changes in the
atmosphere by measuring argon gas with the alpha-particle X-ray

The tradeoff has been that by funneling most available power into
science activities, Spirit has not had much power for sending data to
Earth. That is about to change, because Spirit's on-board memory is
nearly full. Instead of sending data only every fourth day, Spirit will
begin relaying data every day to NASA's Odyssey orbiter for transmission
to Earth.

Rover operators will use the data to plan Spirit's first, post-winter
drive to adjust the rover's position to keep the solar panels facing the
Sun. The move will put the rover in optimum position before solar
conjunction, when Earth and Mars will be on opposite sides of the Sun
and communication will not be possible. Solar conjunction will take
place on Martian days, or sols, 1745-1760 (Nov. 29-Dec. 15, 2008).

Meanwhile, Spirit is healthy, with all subsystems performing as expected
as of sol 1700 (Oct. 14, 2008). Solar-array energy has been 242
watt-hours (100 watt-hours is the amount of energy needed to light a
100-watt bulb for one hour). After weeks of remarkably clear skies,
atmospheric opacity or tau, a measure of the decrease in sunlight caused
by atmospheric dust, has risen slightly to 0.294. Atmospheric dust
levels remain low, but are beginning to trend upward and affect solar
power levels. This increase is expected, as it has occurred at this time
of year in each of the previous three Martian years.

The dust factor -- the percentage of light penetrating dust on Spirit's
solar arrays -- has remained steady. Only 32 percent of the sunlight
reaching the arrays penetrates the dust to generate electricity.

Sol-by-sol summary

In addition to making daily measurements of the amount of atmospheric
dust preventing sunlight from reaching the rover's solar arrays, Spirit
completed the following activities:

Sol 1695 (Oct. 9, 2008): Spirit checked for drift (changes with time) in
the miniature thermal emission spectrometer, surveyed the sky and ground
with the instrument, did survey work with the panoramic camera, and
surveyed a surface target dubbed "Jules Verne" with the miniature
thermal emission spectrometer.

Sol 1696: Spirit surveyed the sky and ground with the miniature thermal
emission spectrometer and made some finishing touches to the lower edge
of the full-color, 360-degree view of the rover's winter surroundings by
acquiring 3 panels of images known as "Bonestell lower tiers" 1, 2, and 3.

Sol 1697: Spirit used the miniature thermal emission spectrometer to
survey the sky, the ground, and a target known as "Stapledon." Spirit
parked the panoramic camera mast assembly with the panoramic camera
pointed below the horizon to minimize dust accumulation.

Sol 1698: Spirit took spot images of the sky for calibration purposes
with the panoramic camera and spent much of the day recharging the battery.

Sol 1699: Spirit surveyed the sky at different elevations as well as the
ground with the miniature thermal emission spectrometer and used the
panoramic camera to survey the horizon and take thumbnail images of the
sky on the rover's right (starboard).

Sol 1700: Spirit surveyed the sky and ground with the miniature thermal
emission spectrometer and took spot images of the sky with the panoramic
camera. Spirit relayed information from Mars to NASA's Odyssey orbiter
for transmission to Earth.

Sol 1701 (Oct. 15, 2008): Spirit surveyed the sky and ground with the
miniature thermal emission spectrometer and monitored dust accumulation
on the panoramic-camera mast assembly.


As of sol 1700 (Oct. 14, 2008), Spirit's total odometry remained at
7,528.0 meters (4.7 miles).
Received on Mon 20 Oct 2008 07:42:03 PM PDT

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