SPIRIT UPDATE: Progress on Long-Term Experiments - sol 860-866, June 9, 2006:
Spirit is healthy and continues to make progress on the rover’s winter science experiments. Spirit has begun work on a new “photon transfer calibration” experiment designed to measure electronic noise (unwanted signals) picked up by CCDs (charge-coupled devices – imaging sensors that convert light into electrical current) in the rover’s cameras. This week the rover conducted the calibration experiment on the panoramic camera and rear hazard-avoidance cameras.
Spirit also began an experiment to look for wind-driven changes in the Martian surface by making the first of several monthly checks, using all 13 filters of the panoramic camera, of a bright soil target nicknamed “Tyrone.” In addition, that camera acquired column 18 of the “McMurdo panorama.” Rover science team members prepared to have the rover remove another 2 millimeters of soil as part of a soil analysis experiment. The newly exposed soil target will be called “Progress 3.”
Sol-by-sol summaries:
Sol 860 (June 4, 2006): Spirit completed 30 minutes of remote sensing and conducted the photon transfer calibration on the panoramic camera. Demonstrating that the rover is capable of multi-tasking, Spirit spent 60 minutes communicating with NASA’s Mars Odyssey spacecraft as Odyssey passed overhead while Spirit also studied Martian terrain targets with the miniature thermal emission spectrometer.
Sol 861: Spirit collected images with the microscopic imager and transmitted 70 megabits of data over UHF frequencies during a morning telecommunications link with Odyssey. Spirit also checked the three-dimensional movement of the rock abrasion tool at the end of the rover’s instrument arm. This process involves taking measurements from encoders, which resemble dials on a safe. The encoders tick off the distance traveled by motor shafts and convert the mechanical motion into electronic signals. The results enable engineers to check for slippage or sticking that would necessitate changes in the amount of movement needed to position the instrument as desired.
Sol 862: Spirit acquired the first part of Column 18 (a 1-by-3 mosaic) of the McMurdo panorama. The rover spent 60 minutes communicating with Odyssey as it passed overhead, while also conducting remote targeted sensing using the miniature thermal emission spectrometer.
Sol 863: Spirit acquired the second half of Column 18 (a 1-by-3 mosaic) of the McMurdo panorama and took a picture of the Martian sunset.
Sol 864: Spirit took a 13-filter color image of the Tyrone soil target using the panoramic camera and conducted analysis of the ground and sky at different elevations using the miniature thermal emission spectrometer.
Sol 865: Spirit completed the photon transfer calibration experiment on the rover’s rear hazard-avoidance cameras.
Sol 866 (June 10, 2006): Plans called for Spirit to use the rock abrasion tool to brush away a third layer of soil 2 millimeters thick from the soil target called Progress. Spirit was to spend 54 minutes on the task as part of a progressive soil brushing experiment before documenting the spot with images from the panoramic camera using all 13 color filters.
Odometry:
As of sol 863 (June 7, 2006), Spirit’s total odometry remained at 6,876.18 meters (4.27 miles).
OPPORTUNITY UPDATE: Opportunity on the Road Again - sol 837-844, June 9, 2006:
Opportunity is healthy, and the team has successfully extracted the rover from the dune called “Jammerbugt.” The rover first backed into this dune on sol 830 (May 24, 2006) to increase its northerly tilt. On sol 833’s drive, the wheels became partially embedded and Opportunity did not make significant progress. The extraction started on sol 836, when the rover was commanded to drive forward over its previous tracks. On sol 841 the extraction was complete. Later in the week Opportunity resumed the drive toward “Victoria Crater.”
Sol-by-sol summaries:
Sol 837 (June 1, 2006): This was the second sol of the extraction effort. Ten steps of one-meter (3.3 feet) each were commanded. To prevent the rover from moving too far or in a way that the team did not expect, the drive commands included checks on tilt, yaw, suspension angles, and distance traveled. Several safety checks, some redundant, were employed to stop the rover after it had safely reached outcrop. Forward motion of approximately 8 centimeters (3.1 inches) was recorded.
Sol 838: Sol 838 was the first sol of a three-sol weekend plan with three identical drives planned. At first, only the sol 838 drive was uplinked to the rover. “Go/no-go” meetings were held over the weekend to review the rover’s progress and decide whether the next drive sequence was safe to uplink. The first sol of the three-sol plan was the third sol of the extraction effort. The drive plan was identical to sol 837’s, except that the wheels were steered slightly down-slope. In 10 meters (33 feet) of commanded motion, only 4.2 centimeters (1.7 inches) of progress was made, with progress decreasing as the drive continued. The wheels were more caked after the drive than before it. Progress seen in this drive was on par with what was observed when Opportunity was embedded in “Purgatory Dune.”
Sol 839: This was the fourth sol of the extraction effort. The sequence was identical to the previous sol’s. Approximately 5 centimeters (2 inches) of progress was made, which was slightly better than in the preceding sol, but with a similar trend of less progress towards the end of the drive. The wheels appeared cleaner.
Sol 840: This was the fifth sol of the extraction effort. The sequence was identical to the previous sol’s. Downlink for this came in about 3 a.m. Monday (June 5, 2006) morning, and it was a great way to start the week. Twenty-eight centimeters (11 inches) of progress was made! The front wheels were significantly less buried and they were cleaner. Based on the Purgatory experience, these were taken as signs that the rover was about to break free.
Sol 841: Sol 841 was the sixth sol of the extraction effort. The sequence was similar to the previous sol’s, but with tighter limits to make sure the rover didn’t exceed the drive goal. Ten steps of one-meter (3.3 feet) each were commanded, but only 3 were executed. After visual odometry measured 2.8 meters (9.2 feet) of progress and a corresponding change in heading, the drive stopped as intended. The first step showed only 18 percent slip, and the next two steps showed essentially no slip. All six wheels reached outcrop! This sol began on June 5, Danish Constitution Day. The holiday commemorates the anniversary of the signing of the Danish Constitution of 1849, which established Denmark as a constitutional monarchy, and also honors the constitution of 1953, which was adopted on the same date. Denmark provided magnet arrays for Opportunity’s and Spirit’s studies of airborne dust. In honor of Danish colleagues, the rover team decided to use Danish names for targets in the area of Opportunity’s current location.
Sol 842: Opportunity took high-resolution imaging of the newly named dune, Jammerbugt, where it had become temporarily embedded. The informal name comes from a bay named Jammerbugt (The Bay of Wailing) on the north coast of Denmark, known for its many shipwrecks. Opportunity also acquired the standard set of post-drive imaging to assist in planning the next drive.
Sol 843: Back on the road again! Opportunity retraced its steps about 5 meters (16.4 feet) back to another outcrop patch. From there, the planned route started south down a trough parallel to the one the team had previously chosen. The rover drove 11.3 meters (37 feet), but no southerly progress was made.
Sol 844 (June 9, 2006): Plans call for a 20-meter (66-foot) drive southward. Slip checks were included in the commands, to stop the drive in case of excessive slip.
Odometry:
As of sol 843 (June 8, 2006), Opportunity’s total odometry is 7,985.5 meters (4.96 miles).