sol 1200-1206, May 31, 2007:
Spirit is still making new discoveries despite dragging its feet, so to speak, after losing use of the right front wheel 426 sols, or Martian days, ago. In the process of creating small trenches while traversing Martian terrain, the dragging right front wheel revealed one of the most astonishing discoveries so far -- exceptionally high silica content in Martian soil, indicative of water at some point in the past. Two of Spirit's scientific instruments -- the alpha-particle X-ray spectrometer and the miniature thermal emission spectrometer -- measured a composition of about 90 percent pure silica in a soil target known as "Gertrude Weise."
Sol-by-sol summary:
In addition to daily observations of atmospheric dust levels using the panoramic camera and surveys of the sky and ground using the miniature thermal emission spectrometer, Spirit completed the following activities:
Sol 1200 (May 19, 2007): Spirit started a 23.25-hour study with the Moessbauer spectrometer and surveyed the rover's tracks as well as targets known as "Josephine Kabick," "Nalda Phillips1," "Nalda Phillips2," "Marilyn Olinger," and "Eileen Burmeister" with the miniature thermal emission spectrometer.
Sol 1201: Spirit watched for morning dust devils, stowed the robotic arm, and bumped backward in 60-centimeter (24-inch) "steps," or intervals. After each step, Spirit scuffed the soil with the left front wheel by rotating the wheel 180 degrees. The rover did this for a distance of 4.19 meters (13.8 feet). After the drive, Spirit acquired images of the scuffed terrain and the terrain ahead with the navigation camera.
Sol 1202: Spirit completed a survey at high sun using the panoramic camera. Spirit acquired panoramic camera images of the scuffed area and surveyed Gertrude Weise with the miniature thermal emission spectrometer. The rover searched for dust devils by acquiring navigation camera movies in coordination with overhead observations by the High Resolution Science Imaging Experiment on board the Mars Reconnaissance Orbiter.
Sol 1203: Spirit monitored dust on the rover mast and watched for dust devils in the morning. Spirit acquired navigation camera images before driving 6.68 meters (21.9 feet) around obstacles en route to "Home Plate." After the drive, Spirit acquired images with the hazard avoidance cameras and navigation camera.
Sol 1204: Spirit spent the first part of the sol analyzing the rover's external calibration target with the miniature thermal emission spectrometer, searching for clouds with the navigation camera, and acquiring movies in search of dust devils with the navigation camera. The rover then acquired image mosaics of the dune field known as "El Dorado" with the panoramic camera in addition to systematic foreground data with the miniature thermal emission spectrometer. Spirit acquired navigation camera images, searched again for dust devils, and acquired more panoramic camera images.
Sol 1205: Spirit completed a systematic ground survey with the panoramic camera, unstowed the robotic arm, brushed the surface of a target known as "Pesapallo," acquired stereo microscopic images of the surface, then placed the alpha-particle X-ray spectrometer on it. Spirit acquired data with the alpha-particle X-ray spectrometer for 18.75 hours.
Sol 1206 (May 25, 2007): Spirit searched for morning dust devils, retracted the robotic arm, and placed the Moessbauer spectrometer on Pesapallo. The rover acquired Moessbauer spectrometer data for 23 hours. Spirit acquired panoramic camera images of a target known as "Bullpen" and miniature thermal emission spectrometer data from a target known as "Joyce Steel." The following morning, Spirit was scheduled to conduct a survey of the horizon with the panoramic camera in addition to studies with the miniature thermal emission spectrometer.
Odometry:
As of sol 1204 (May 23, 2007), Spirit's total odometry was 7,120.34 meters (4.42 miles).
