SPIRIT UPDATE: Moving On From 'Pot-of-Gold' - sol 171-174, July 02, 2004
On sol 171, Spirit continued its investigation in "Hank's Hollow" and the rock target "Pot-of-Gold." The rober successfully completed observations of the abraded area with the microscopic imager and alpha particle X-ray spectrometer.
On sol 172, Spirit looked at the sky with the miniature thermal emission spectrometer and panoramic camera. The rover also acquired some thermal inertia observations of nearby soil with the miniature thermal emission spectrometer. Spirit finished up its Pot-of-Gold observations with some microscopic images and a final long MÃ¶ssbauer integration of the abraded surface.
On sol 173, Spirit performed atmospheric observations with the miniature thermal emission spectrometer and panoramic camera. The rover also took some panoramic camera context images for the sol 172 thermal inertia observations. The rover finished the day's work by stowing the instrument deployment device and doing a "bump-back" to the "Bread Box" target. One last panoramic camera shot of Pot-of-Gold ended up a bit overexposed and will need to be retaken.
On sol 174, Spirit began the day acquiring atmospheric observations with the mini thermal emission spectrometer and panoramic camera. The rover then imaged the drive direction with the panoramic camera. Last but not least, Spirit took a look at a disturbed area of soil called "Bright Tracks" with the panoramic camera to help scientists learn more about the very bright material found here.
During the next 15 or more sols, rover planners will perform a "3,000 meter tune-up" on Spirit before the rover embarks on a climb up the hills.
The tune-up will include a number of elements including:
A front hazard avoidance camera calibration where a series of robotic arm poses and hazard avoidance camera images will be used to refine the rover planners' ability to target objects using stereo hazard avoidance camera images. The team is currently experiencing a 2 to 3 centimeter (slightly less or slightly greater than an inch) error in predicted versus actual target locations in the vicinity of the instrument deployment device.
Spirit's first deep sleep. Deep sleep is a mode that leaves the rover completely un-powered overnight, saving the energy that would be spent powering rover electronics and survival heaters that are normally on even when the rover is napping. Spirit needs deep sleep to save energy in the coming sols. Since deep sleep is potentially harmful to the mini thermal emission spectrometer instrument because its survival heater is not powered, rover planners have identified two observations that must be completed before the first deep sleep is attempted. Opportunity has been using deep sleep for several weeks now.
A right front wheel lubrication. Spirit's right front wheel continues to draw roughly twice the current of the other wheels. Spirit will drive to "Engineering Flats," a relatively flat, hazard-free area where rover planners will execute a series of diagnostic drive tests and heating sequences over the course of four to five sols. The intent is that the heating will re-flow the lubricants in this actuator, correcting the problem. Engineering Flats is roughly 7 meters (nearly 23 feet) from Spirit's current location.
Engineering tests of visual odometry. Visual odometry uses navigation camera images taken during a drive to determine the rover's location. This rover feature has been improved and is ready for trial runs now. Rover planners would like to use it on a regular basis to get Spirit where they want it to go more quickly. Due to slippage, Spirit sometimes needs two or more sols to make a short approach when using the blind drive technique.
OPPORTUNITY UPDATE: Ravenous Rock Abrasion Tool - sol 150-153, July 01, 2004
On Sol 150, Opportunity completed MÃ¶ssbauer spectrometer observations in the rock abrasion tool hole on the rock "Tennessee" (hole number 3). The rover then stowed its arm, drove 0.55 meters (1.8 feet) backwards, turned to 40 degrees and then drove 1 meter (3.3 feet) forward. That was a net forward motion of 0.45 meters (1.5 feet) down-crater. This drive enabled Opportunity to reach two targets in the fifth distinct layer (E) of "Endurance Crater." The night of sol 150 into morning of sol 151, Opportunity did not do a deep sleep.
It was time to get to work again drilling another rock abrasion tool hole on sol 151. Opportunity began the sol by performing panoramic camera images, then it unstowed its arm and used the microscopic imager to capture the next drilling target, "Grindstone." After using the microscopic imager, Opportunity spend two hours grinding and created another precise hole. Upon completing the grinding operation, Opportunity placed the MÃ¶ssbauer in the hole and performed a long integration. Opportunity did a mini-deep sleep operation overnight from sol 151 into the morning of sol 152. The miniature thermal emission spectrometer reached a chilly -51 degrees Celsius overnight.
On sol 152, Opportunity completed the observations on the hole on Grindstone. When the rover woke up from deep sleep at 7:00a.m. local solar time, it turned on the MÃ¶ssbauer spectrometer and integrated until mid-afternoon. When the MÃ¶ssbauer integration was complete, the rover switched tools to place the alpha particle X-ray spectrometer in the hole.
On sol 153 Opportunity ended the alpha particle X-ray spectrometer integration, and set its sights on still another rock abrasion tool target. This time Opportunity stretched its arm out just a little farther down into the crater to a target called "Kettlestone." Grinding again for just over two hours, Opportunity successfully created the fifth hole on the slopes of Endurance Crater. The last two grind operations took place on a slope of -25.6 degrees. Just as on sol 151, after completing the drilling operation, Opportunity placed the MÃ¶ssbauer spectrometer in the new hole and collected data late into the night. Shutting down late at night, Opportunity deep slept until 7:00a.m. local solar time on sol 154.
Total odometry after sol 153 was 1468.46 meters (0.91246 mile).