[meteorite-list] Mars Exploration Rovers Update - October 15-29, 2008

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon, 10 Nov 2008 10:25:02 -0800 (PST)
Message-ID: <200811101825.KAA12340_at_zagami.jpl.nasa.gov>

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

SPIRIT UPDATE: Spirit Begins Driving Uphill - sol 1709-1715,
October 23-29, 2008:

With the Sun moving higher in the sky, Spirit's solar panels must move
in the same direction to maximize their exposure to sunlight. To achieve
optimal solar input, the panels still must tilt to the north, but not as
steeply as before. To change the tilt, rover drivers have begun moving
Spirit back upslope toward the top of "Home Plate." Their goal is to
reduce the rover's northerly tilt from 30 degrees to 20 degrees.

The change in tilt is vital, as Spirit is seeing the lowest energy
levels of the mission. On Martian day, or sol, 1713 (Oct. 27, 2008),
solar-array energy dropped to 207 watt-hours (that's enough energy to
light a 100-watt bulb for slightly longer than two hours). The drop in
energy was partly due to an increase in atmospheric dust believed to be
related to distant dust storm activity. The same day, dust-related loss
of visibility, known as Tau, reached a high of 0.69 before dropping to
0.60 on sol 1715 (Oct. 29, 2008).

Because of the limited solar energy, the energy used for driving comes,
in part, from the rover's batteries. As solar energy improves, Spirit
will have to dip less into the batteries for driving. Fortunately,
temperatures are warmer now than in the depths of winter. As a result,
the dip in battery reserves is not nearly as great as it would have been
if Spirit also required more battery power for heating.

So far, rover drivers are pleased with Spirit's progress. The rover
completed three upslope drives to achieve a northerly tilt of 21.8
degrees. Rover operators hope that a couple more budges will give Spirit
a northward tilt of 20 degrees.

Eventually, if Spirit can drive all the way back on top of Home Plate,
the rover will save a significant amount of time while heading out on
the next science campaign. If necessary, Spirit still has the option of
driving downslope.

Spirit is healthy, with all subsystems performing as expected as of sol
1715 (Oct. 29, 2008).

Sol-by-sol summary

In addition to measuring dust-related changes in atmospheric clarity
each day with the panoramic camera and relaying data to Earth each
evening via NASA's Odyssey orbiter, Spirit completed the following
activities:

Sol 1709 (Oct. 23, 2008): Spirit checked for drift (changes with time)
in the miniature thermal emission spectrometer and surveyed the sky and
ground with the instrument. Spirit then began inching uphill, and after
the drive, took a single-frame image to document progress with the
navigation camera.

Sol 1710: Spirit surveyed the horizon with the panoramic camera, drove,
and acquired images with the hazard-avoidance cameras as well as a
quarter-frame image of the spacecraft deck with the panoramic camera.

Sol 1711: Spirit checked for drift (changes with time) in the miniature
thermal emission spectrometer and completed a mini-survey of the sky and
ground with the instrument.

Sol 1712: Spirit monitored dust on the panoramic-camera mast assembly
and recharged the batteries..

Sol 1713: Spirit checked for drift (changes with time) in the miniature
thermal emission spectrometer and completed a mini-survey of the sky and
ground with the instrument. Spirit drove a bit farther upslope.

Sol 1714: Spirit acquired a single-frame, post-drive image with the
navigation camera as well as images with the hazard-avoidance cameras.

Sol 1715 (Oct. 29, 2008): Spirit checked for drift (changes with time)
in the miniature thermal emission spectrometer and completed a
mini-survey of the sky and ground with the instrument. The rover then
calibrated the spectrometer and began inching upslope again. After the
drive, Spirit took a single-frame image with the navigation camera as
well as images with the hazard avoidance cameras.

Odometry:

As of sol 1715 (Oct. 29, 2008), Spirit's total odometry remained at
7,528.42 meters (4.68 miles).

------------------------------------------------------------------------

OPPORTUNITY UPDATE: Farewell, Victoria, and on to Endeavour! -
sol 1681-1687, October 15-21, 2008:

Opportunity took the last images of "Victoria Crater" before beginning
the journey to Endeavour Crater. The final focus of the rover's cameras
was a cliff at the edge of Victoria nicknamed "Cape Victory." After
spending more than two years investigating this spectacular crater,
Opportunity took parting images as Victoria disappeared into the
distance. The rover first arrived at the rim of Victoria on sol 952
(September 28, 2006), at the top of a sloping alcove known as "Duck Bay."

Opportunity has made good progress, driving more than 314 meters (1,030
feet)! Near the end of that leg of the journey, Opportunity began to see
small ripples about 10 centimeters (4 inches) high.

Opportunity completed work on images of the miniature thermal emission
spectrometer after the shake test performed on Sol 1680 (Oct. 14, 2008).
That's when the rover shook the instrument's pointing mirror for 3
seconds to try to shake dust off the mirror. In the end, images did not
show a measurable improvement, but rover planners aim to try again in
the near future.

Other remote sensing highlights for the week included panoramic-camera
imaging of some boulder tracks within Victoria, along with the usual
observations of the sky, clouds, atmospheric dust, and dust accumulation
on the rover itself.

Opportunity is healthy, with all subsystems performing as expected as of
Martian day, or sol, 1687 (Oct. 22, 2008). Power has been averaging 589
watt-hours during the past week (100 watt-hours is the amount of energy
needed to light a 100-watt bulb for one hour.) This is a slight decrease
from the week before and is the result of slightly elevated dust levels
in the atmosphere and a change in the orientation of Opportunity's solar
panels.

Sol-by-sol summary

In addition to measuring daily, dust-related changes in atmospheric
clarity with the panoramic camera and sending regular updates to Earth
by relaying data to NASA's Odyssey orbiter, Opportunity completed the
following activities:

Sol 1681 (Oct. 15, 2008): Opportunity acquired images of boulder tracks
inside Victoria Crater and surveyed the sky at high Sun with the
panoramic camera. The rover checked for drift (changes with time) in the
miniature thermal emission spectrometer, conducted a utility test of the
instrument as well as a post-shake test calibration of observations of
the ground and sky.

Sol 1682: In the morning, Opportunity used the panoramic camera to take
super-resolution images of Cape Victory, a 3-by-1 panel of frames of the
area around Cape Victory, and thumbnail images of the sky for
calibration purposes. The rover searched for morning clouds with the
navigation camera. Before driving, Opportunity took a 3-by-1 panel of
panoramic-camera images of a target known as "Iceland," then moved a
short distance for a long-baseline, stereo panorama. Opportunity
acquired post-drive images with the panoramic and navigation cameras,
including a 7-by-1 panel of rearward-looking images.

Sol 1683: In the morning, Opportunity took spot images of the sky for
calibration purposes and surveyed the horizon with the panoramic camera.
The rover then acquired part 2 of the long-baseline, stereo panorama
begun the day before. Opportunity acquired post-drive images with the
panoramic and navigation cameras.

Sol 1684: Opportunity took thumbnail images of the sky with the
panoramic camera in the morning. The rover measured argon gas in the
Martian atmosphere with the alpha-particle X-ray spectrometer.

Sol 1685: Opportunity began the day by surveying the horizon with the
panoramic camera and searching for morning clouds with the navigation
camera. At midday, Opportunity took images measuring albedo (surface
reflectivity) with the panoramic camera.

Sol 1686: Opportunity took morning, spot images of the sky and
full-color, systematic, foreground images with the panoramic camera.
Opportunity completed the day's drive and performed a "get quick fine
attitude" to determine the rover's precise position relative to the Sun.
After the drive, Opportunity acquired image mosaics with the navigation
and panoramic cameras.

Sol 1687 (Oct. 21, 2008): Opportunity started the day by surveying the
horizon with panoramic camera, searching for clouds with the navigation
(which involves taking six time-lapse movie frames), and monitoring dust
on the panoramic-camera mast assembly. The rover then continued driving
and acquired images just before and after completing the drive with the
navigation and panoramic cameras. Plans for the following day called for
Opportunity to take spot images of the sky and make the usual
measurements of atmospheric dust.

Odometry

As of sol 1687 (Oct. 21, 2008), Opportunity's total odometry was
12,677.65 meters (7.88 miles).
Received on Mon 10 Nov 2008 01:25:02 PM PST