[meteorite-list] Mars Exploration Rovers Update: April 30 - May 6, 2009

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Sun, 10 May 2009 18:32:28 -0700 (PDT)
Message-ID: <200905110132.SAA04739_at_zagami.jpl.nasa.gov>

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

SPIRIT UPDATE: Another Power Boost, But Difficult Driving - sols
1893-1899, April 30 - May 6, 2009:

Spirit has now completed 19 sols of operation without any recurrence of
the anomalous behavior that happened between Sol 1872 (April 9, 2009)
and Sol 1881 (April 18, 2009). In addition to changes made to the
rover's wake-sleep cycle and internal data logging, a new ability to
detect "amnesia" events has been implemented. There is still no
explanation for the previous anomalies, and the investigation is
continuing.

Spirit is currently challenged by some very difficult terrain on the
west side of Home Plate. The rover encountered very loose, soft material
while driving south on its current path. So Spirit is now in the process
of backing out. However, with only five driving wheels, its progress has
been very difficult. Only centimeters have been achieved over the last
four drive sols. It is expected that extracting Spirit from this
location will require many more drive sols.

The good news is that Spirit experienced another solar array dust
cleaning event. On Sol 1899 (May 6, 2009), energy production improved by
more than 25 percent.

As of Sol 1899 (May 6, 2009), Spirit's solar array energy production is
about 500 watt-hours, equivalent to what is needed to light a 100-watt
bulb for five hours. Atmospheric opacity (tau) is at 0.821. The dust
factor has improved substantially to 0.515, meaning that about 51.5
percent of sunlight hitting the solar array penetrates the layer of dust
on the array. Spirit has more solar array energy than Opportunity for
the first time in a very long time. Spirit's total odometry is 7,729.93
meters (4.80 miles).

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

OPPORTUNITY UPDATE: Study an Outcrop While Resting a Wheel -
sols 1872-1878, April 30 - May 6, 2009:

After moving around a troublesome ripple, on Sol 1872 (April 30, 2009)
Opportunity performed a dog-leg maneuver heading south and achieving
about 42 meters (138 feet) of distance. Electrical current levels in the
right-front wheel have resumed larger-than-normal levels. The next
drive, on Sol 1873 (May 1, 2009), was backward for about 50 meters (164
feet). The wheel currents remained elevated.

The project decided to take advantage of a contact-instruments science
campaign to rest the actuator again. So on Sol 1877 (May 5, 2009), a
short bump was performed to position the rover on exposed rock outcrop
for the contact science. That work will proceed over the next several
sols while the right front wheel actuator rests.

As of Sol 1877 (May 5, 2009), Opportunity's solar array energy
production is 491 watt-hours, the atmospheric opacity (tau) remains
around 0.811 and the dust factor is 0.609.

Opportunity's total odometry as of Sol 1878 (May 6, 2009) is 15,902.37
meters (9.88 miles).
Received on Sun 10 May 2009 09:32:28 PM PDT