13 Oct 2004
(Source: Jet Propulsion Laboratory)
OPPORTUNITY UPDATE: Working towards 'Wopmay' - sol 245-250, October 13, 2004
Opportunity is in excellent health. The current pattern is to use the deep-sleep mode every second night, and to support an early morning Odyssey communications pass on the non-deep-sleep nights. Opportunity is experiencing good solar exposure, averaging more than 660 watt-hours per sol from the solar arrays. The rover is poised for final approach to "Wopmay," a fascinating creviced rock with a brain-like appearance.
Sol 245 was a restricted sol. Opportunity could perform only remote sensing. The rover took images in all directions with its navigation camera. It used its miniature thermal emission spectrometer for sky and ground observations. Then it went into deep sleep for the night of sol 245 into the morning of sol 246.
Sols 246 through 248 were planned in a single planning cycle as part of our 5-day-a-week schedule. The uplink team accomplished a Herculean task, successfully completing and uplinking three science-intensive sol plans despite some issues encountered during the day.
Opportunity began sol 246 by placing the Mossbauer spectrometer and starting a long reading with it on a target called "Void." While collecting the Mossbauer data, Opportunity also performed two hours of observations with its panoramic camera and its miniature thermal emission spectrometer. The Mossbauer integration was paused just before the afternoon communication session with Mars Odyssey. Deep sleep was disabled so that Opportunity could support an early morning communications session on sol 247 and restart the Mossbauer integration.
Sol 247 was day two of the long Mossbauer integration; the integration ran throughout the sol until early evening, at which time Opportunity again paused and entered deep sleep overnight. During the day, Opportunity also completed a series photometric observations with its panoramic camera.
On sol 248 Opportunity exited deep sleep and restarted the Mossbauer integration. During pre-uplink science activities in the early morning, the rover completed a sky observation pattern that planners call an itty-bitty cloud movie. In the martian afternoon, Opportunity ended the long Mossbauer integration and turned the tool turret on its arm to place the alpha particle X-ray spectrometer on Void. The X-ray instrument did not start taking data until early the next morning. Opportunity did not go into deep sleep overnight. Instead, it used an early morning Odyssey communications session and immediately afterwards started the alpha particle X-ray spectrometer integration.
Opportunity completed the alpha particle X-ray spectrometer integration on the morning of sol 249. The rover then performed a series of microscopic imaging activities, stowed the instrument deployment device and began driving toward its next target, Wopmay. The 19.98-meter (about 66-foot) drive went well, but with more slippage than expected. At the end of the drive, the nearest visible face of Wopmay was only 2 meters (about 7 feet) from the center of the rover; far enough not to have been a hazard during the drive, but closer than was predicted. Slip estimates indicate radial slippage as high as 64 percent. Opportunity used deep sleep overnight on sol 249.
On sol 250, which ended on Oct. 7, Opportunity performed the first part of a planned two-sol approach to Wopmay. This nearly 7-meter (23-foot) drive went well. The end of the drive incorporated conditional arcs to be executed only if the rover was in the appropriate position. The drive put the rover in very good position for the final approach on sol 251.
Total odometry after sol 250 puts Opportunity just over the one-mile mark: 1,611.99 meters (1.0016 mile)!