Mars Exploration Rovers Update - July 17-31, 2008

SPIRIT UPDATE: With Batteries Charged, Spirit is Ready for More
Science

  • sol 1621-1627, July 25-31, 2008:

Spirit has fully recovered from a recent rundown in battery power.
Energy has improved to levels not seen since sol (Martian day) 1604
(July 7, 2008). The hit in battery energy was primarily the result of
data transmissions taking place later in the day, when less solar
energywas available.

During the past week, rover planners eliminated the late
communicationssessions. Spirit is not scheduled to have another one until sol 1636
(Aug. 9, 2008). To mitigate the impact that one will have on power,
rover planners plan to shorten the duration of data transmission from
20 minutes to only 10 minutes. This will allow sufficient time to get new
instructions on board the rover while minimizing battery drain.

A transmitter problem thwarted data transmission on sol 1625 (July 29,
2008). The uplink from Earth was to have loaded activity plans and
maintenance instructions for sols 1626, 1627, 1628 and 1629 (July
30-Aug. 2, 2008). The sequences already on board Spirit were designed
with built-in contingency plans to handle just such an event. As a
result, while Spirit continues the “runout” portion of the earlier
master sequence, rover operators will send a new set of commands for
sols 1630, 1631 and 1632 (Aug. 3-5, 2008) on sol 1629 (Aug. 2, 2008).

Spirit remains healthy, with all subsystems performing as expected as
of sol 1626.

Sol-by-sol summary

In addition to using the panoramic camera to make daily measurements
of dust-related changes in visibility, Spirit completed the following
activities:

Sol 1621 (July 25, 2008): Spirit recharged the batteries.

Sol 1622: Spirit received instructions from Earth via the rover’s
high-gain antenna and relayed data to NASA’s Odyssey orbiter via the
rover’s UHF antenna.

Sol 1623: Spirit acquired images of sand formations with the rear
hazard-avoidance and navigation cameras. The rover took six, time-
lapse, movie frames in search of clouds with the navigation camera, as well
as images of the sky (called “sky flats”) for calibration purposes.

Sol 1624: Spirit recharged the batteries.

Sol 1625: Spirit took spot images of the sky for calibration purposes
with the panoramic camera and acquired movie frames in search of
clouds with the navigation camera.

Sol 1626: Spirit completed a horizon survey with the panoramic camera
and relayed data to Odyssey for transmission to Earth.

Sol 1627 (July 31, 2008): Spirit recharged the batteries.

Odometry:

As of sol 1626 (July 30, 2008), Spirit’s total odometry remained at
7,528.0 meters (4.7 miles).


OPPORTUNITY UPDATE: Opportunity Fights Uphill Battle - sol 1593-1599,
July 17-23, 2008:

“Victoria Crater” continues to challenge Mars rover drivers as they
try to find a location where Opportunity can do scientific studies of
rocks near the “Cape Verde” cliff face. They have been trying to drive the
rover to a location nicknamed “Nevada” after a rock shaped somewhat
like the state of Nevada. Getting there, however, has been challenging.

After attempting unsuccessfully to drive the rover on steep slopes
that caused the wheels to slip, they are aiming for a new location. They
have identified a large flagstone to the left of Nevada that offers solid
footing and a low amount of tilt. They hope to drive the rover there,
re-evaluate the terrain, and re-assess whether it is possible to reach
Nevada.

They are also working on a campaign to have Opportunity document
different styles of weathering on local rocks. The rover, meanwhile,
continues to measure argon gas in the Martian atmosphere and make
other atmospheric observations.

Opportunity remains healthy, with all subsystems performing as
expected as of the rover’s 1,599th Martian day, or sol (July 23, 2008), of
exploration. Solar energy on the vehicle has been averaging just under
360 watt-hours (100 watt-hours is the amount of energy needed to light
a 100-watt bulb for one hour).

Sol-by-sol summary:

In addition to making daily assessments of atmospheric dust based on
the darkness of the sky as viewed by the panoramic camera and relaying
data to NASA’s Odyssey orbiter for transmission to Earth, Opportunity
completed the following activities:

Sol 1593 (July 17, 2008): Opportunity drove and took post-drive images
of the surrounding terrain with the hazard-avoidance and navigation
cameras. After communicating with Odyssey, the rover went into a deep
sleep.

Sol 1594: Opportunity spent 4 hours and 15 minutes integrating
measurements of atmospheric argon with the alpha-particle X-ray
spectrometer. The rover went into a mini-deep sleep.

Sol 1595: Opportunity took full-color images, using all 13 filters of
the panoramic camera, of rock exposures dubbed “Mawson,” “Murchison,”
“Mackay,” and “King.” After sending data to to Odyssey, the rover went
into a deep sleep.

Sol 1596: Opportunity monitored dust on the rover mast, drove, and
took post-drive images with the hazard-avoidance and navigation cameras.
After the day’s activities, the rover went into a deep sleep.

Sol 1597: Opportunity took full-color images, using all 13 color
filters of the panoramic camera, of rock exposures nicknamed “Playfair” and
“Eugene_Smith.” After relaying data to Earth, Opportunity went into a
deep sleep.

Sol 1598: In the morning, Opportunity took four freeze-frame images
with the navigation camera for a movie to document potential clouds.
Following a short drive, Opportunity took images with the
hazard-avoidance and navigation cameras. After sending data to
Odyssey, the rover measured atmospheric argon with the alpha-particle X-ray
spectrometer.

Sol 1599 (July 23, 2008): Opportunity took more full-color,
panoramic-camera images of Mackay and Mawson. Plans for the following
morning called for Opportunity to take full-color images of Murchison.

Odometry:

As of sol 1598 (July 22, 2008), Opportunity’s total odometry was
11,725.96 meters (7.29 miles).