[meteorite-list] Mars Exploration Rover Update - September 10, 2007

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 11 Sep 2007 08:29:58 -0700 (PDT)
Message-ID: <200709111529.IAA28444_at_zagami.jpl.nasa.gov>

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

SPIRIT UPDATE: Spirit Finally Arrives at Home Plate! - sol 1303-1308,
September 10, 2007:

After remaining beyond the margins of Home Plate ever since exiting its
northeast edge on Sol 774 (March 7, 2006) to survive the first winter on
Mars, Spirit finally climbed on top of the elevated, circular plateau
that scientists believe is volcanic in origin.

Before completing the final drive, however, Spirit returned to the soil
patch nicknamed "Gertude Weise," made of nearly pure silicon dioxide, to
acquire data that will help scientists characterize how much dust has
accumulated on the instrument optics of the miniature thermal emission
spectrometer.

The miniature thermal emission spectrometer is inside the boxy body of
the rover, below the mast. Mirrors inside the mast allow the instrument
to see outside. The rover has been using the spectrometer to measure
changes in the atmosphere during the recent dust storm on Mars. When the
instrument is not in use, a cover protects it from dust floating in the
atmosphere but it isn't air-tight.

After completing measurements of Gertrude Weise, Spirit was once again
on the move. The rover attempted to "thread the needle" by driving
between two rocks on sol 1304 (Sept. 3, 2007) and place the rear two
wheels on the top of Home Plate (Spirit must drive backward to drag the
frozen right front wheel).

As it turned out, the drive was more difficult than anticipated. On the
first attempt, Spirit immediately stopped driving when the rover's
wheels entered an area designated as a keepout zone. This occurred as
the rover was attempting to compensate for drag from the right front
wheel by turning slightly in the opposite direction. Normally, the
dragging wheel causes Spirit to yaw counter-clockwise (as viewed from
above), but the amount of counter-clockwise spin depends on the amount
of drag encountered by the right front wheel. Rocky surfaces cause less
drag than soil. In this case, the drag was less than anticipated.

On sol 1306 (Sept. 5, 2007), Spirit tried again and executed the drive
flawlessly! Now that the rover's two rear wheels are on top of the
eastern edge of Home Plate, Spirit is in position to explore the top of
the elevated plateau along its eastern and southern edges. The next
planned stop is a few meters away in an area known as "Site 2," located
midway along the eastern scarp of Home Plate east scarp and several
meters to the west of the scarp. (If you compared the roughly circular
shape of the top of Home Plate to a clock, Site 2 would be at 3:30.)

After that, scientists plan to have Spirit proceed to "Site 3," at the
southern end of Home Plate (6 o'clock position) and "Site 4," at the
southwestern corner of Home Plate (7:30 position).

By collecting data at all these sites, scientists hope to interpret the
geologic structure of Home Plate, determine how the rock chemistry
changes from one side to the other, and elucidate a fracture that
crosses the plateau from west to east. Along the way, the rover will
take images of the south face of "Husband Hill" to the north and
outcrops known as "Goddard" and "von Braun" to the south.

In recent months, rover handlers have been naming local features and
targets around Home Plate for deceased members of the All-American Girls
Professional Baseball League. Because Home Plate is bowl-shaped,
scientists have decided to name features on top of Home Plate after
things served in bowls. Stay tuned for upcoming yummy descriptions!

Sol-by-sol summary:

In addition to measuring atmospheric opacity with the panoramic and
navigation cameras, surveying the sky and ground with the miniature
thermal emission spectrometer, and checking for drift (changes with
time) in the miniature thermal emission spectrometer, Spirit completed
the following activities:

Sol 1303 (Sept. 2, 2007): Spirit studied a target known as "Gertrude
Weise14," the background of the target, a soil target labeled "Innocent
Bystander Disturbed Area 1," and a target known as "Mary Dailey3" as
well as its background with the miniature thermal emission spectrometer.
Spirit recalibrated the panoramic camera and acquired miniature thermal
emission spectrometer data on a target dubbed "Joanne Winter2."

Sol 1304: Spirit acquired full-color images of the disturbed soil area
using all 13 filters of the panoramic camera before driving 2.42 meters
(7.94 feet) toward Home Plate. The rover took images just before and
after completing the drive with the hazard avoidance cameras as well as
post-drive images with the navigation and panoramic cameras.

Sol 1305: Spirit surveyed the rover's external calibration target using
the miniature thermal emission spectrometer and acquired movie frames in
search of dust devils using the navigation camera. The rover
recalibrated the panoramic camera.

Sol 1306: Before beginning the sol's drive, Spirit acquired full-color
images of the rover's external calibration target as well as the
disturbed soil area of Innocent Bystander using all 13 filters of the
panoramic camera. After completing the 8.21-meter (26.9-foot) drive, the
rover took images of the surrounding terrain with the navigation camera
and forward-looking images with the panoramic camera.

Sol 1307: Spirit completed a survey of rock clasts with the panoramic
camera and assessed the calibration target with the miniature thermal
emission spectrometer.

Sol 1308 (Sept. 7, 2007): Spirit acquired images of dust in the sky with
the panoramic camera, calibrated the miniature thermal emission
spectrometer, and listed files in the rover's flash memory (a type of
rewritable electronic memory that retains information even when power is
off). Spirit completed a systematic foreground survey using all 13
filters of the panoramic camera and measured albedo (surface
reflectivity) using the panoramic camera. With the miniature thermal
emission spectrometer, the rover surveyed a soil target known as
"Beef_Chili," a rock target known as "Cajun_Chili," and the external
calibration target.

Odometry:

As of sol 1306 (Sept. 5, 2007), Spirit's total odometry was 7,182.49
meters (4.46 miles).
Received on Tue 11 Sep 2007 11:29:58 AM PDT