[meteorite-list] Mars Exploration Rovers Update - May 10, 2004

[Ron Baalke]

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

SPIRIT UPDATE: Spirit Surpasses the One-Mile Mark! - sol 121-123, 
May 10, 2004

On sol 121, after a brief nap, Spirit conducted atmospheric 
measurements before continuing its trek toward the "Columbia 
Hills." A 96.8 meter (318 feet) drive that consisted of about 
half direct drive and half auto-navigational drive broke Spirit's 
last one-sol distance traveled. That drive brought the mission 
total to 1,669 meters (1.04 miles), flipping the rover's odometer 
over the one-mile mark.

Sol 122 was a touch-and-go day, starting with a half-hour alpha 
particle X-ray spectrometer integration, a one-hour Mössbauer 
integration and a set of four microscopic images all on the same 
patch of soil.  Panoramic camera and miniature thermal emission 
spectrometer data were also obtained before an afternoon nap. The 
bulk of the afternoon was spent driving another 65 meters (213 
feet).

Sol 123 started off with Panoramic camera and miniature thermal 
emission spectrometer observations for near-field surveys, 
atmospheric studies, and localization. Spirit then took a 
half-hour nap, followed by the day's drive. This sol consisted 
of another 48-meter (about 157-feet) direct drive, the mid-drive 
survey and localization remote sensing, and then 47-meters (about 
154 feet) of driving using auto-navigation. The total was 95.2 
meters (312 feet), bringing the mission total to 1830 meters 
(1.14 miles).



OPPORTUNITY UPDATE: 'Deep Sleep' Gives Opportunity More Energy to 
Cruise the Crater - sol 101-102, May 10, 2004

Opportunity awoke on sol 102 from its first "deep sleep." This set 
of activities was initiated to conserve the energy that is being 
used by the instrument arm's stuck-on heater switch. During deep 
sleep, rover planners power off the main electronics at night and 
open the switches that supply battery power to the main power bus, 
and in turn nearly all the secondary electronics. In particular 
this removes power input to the Rover Power Distribution Unit, 
which normally supplies power to the stuck-on heater. With the 
Rover Power Distribution Unit input turned off, the heater cannot 
burn any energy either. In the morning, when the sun strikes the 
solar panel array, the Battery Control Board resets and connects 
the batteries to the main power bus again. At this time, the 
stuck-on heater again draws power, but this will only be for a few 
hours in the morning instead of all night.

The most vulnerable instrument to the cold martian nights is the 
miniature thermal emission spectrometer.  With a cutoff of the 
power electronics, its heater cannot keep it warm overnight. Data 
returned on sol 102 showed the temperature reached -46 degrees 
Celsius (-50.8 degrees Fahrenheit), a bit warmer than the 
spectrometer's lowest proven temperature for functionality, -50 
degrees Celsius (-58 degrees Fahrenheit).

Rover planners commanded Opportunity to take a drive during the 
afternoon of sol 102 to the south, along the edge of the crater 
toward a dark rock in the vicinity.

More remote sensing was conducted, including miniature thermal 
emission spectrometer measurements that confirmed the instrument 
is still functioning normally after deep sleep.

Wake-up songs for the sols were "Morning has Broken" by Cat 
Stevens; "Hallelujah Chorus" from George Frideric Handel's Messiah; 
and "Dazed and Confused" by Led Zeppelin.