Spirit is healthy and making good progress downhill. The rover performed an extensive campaign with the tools on the robotic arm at an outcrop called "Larry's Bench" and made targeted observations with other instruments. The team has been taking advantage of every drive sol, averaging about 40 meters (131 feet) per sol.
Mars is currently passing through a debris trail of Halley's comet, and Spirit is attempting to observe resulting meteor showers with the panoramic camera at night.
Sol-by-sol summaries:
Sol 660 (Nov. 11, 2005): Spirit performed robotic-arm work on Larry's Bench. Spirit took pictures of Larry's Bench with the microscopic imager before and after the rock abrasion tool brushed the area. Spirit used the panoramic camera to take pictures of the eastern part of the hill and took images in the direction Spirit plans to drive. Spirit used the alpha particle X-ray spectrometer and attempted to observe the Odyssey orbiter at night.
Sol 661: Spirit performed a long integration with the Moessbauer spectrometer, targeted observations with the panoramic camera (pointed towards "Husband Hill" summit), and targeted stares with the miniature thermal emission spectrometer.
Sol 662: Spirit performed a long integration with the Moessbauer spectrometer, targeted observations with the panoramic camera, atmospheric science, and more stares with the miniature thermal emission spectrometer.
Sol 663: Spirit performed a long integration with the Moessbauer spectrometer, made targeted observations with the panoramic camera and miniature thermal emission spectrometer, and did a meteor search at night.
Sol 664: Spirit stowed the robotic arm, took panoramic-camera images of the arm's work area, and drove 38 meters (125 feet) downhill.
Sol 665: Spirit drove 42 meters (138 feet) downhill.
Sol 666: Spirit drove 40 meters (131 feet) downhill.
Sol 667: No scientifically outstanding targets for the robotic arm were seen near the rover's current location, so the team planned a long drive. The team does not have good images that show the view over the ridge, so the rover will use autonomous navigation and drive with a reduced tilt limit to traverse safely downhill.
As of the end of sol 667, (Nov. 18, 2005), Spirit has driven 5,392 meters (3.35 miles).
------------------------------------------------------------------------
OPPORTUNITY UPDATE: Opportunity Gains Energy and Hits Four-Mile Mark - sol 641-648, Nov 18, 2005:
Opportunity is healthy. The solar array was apparently cleaned again on sol 638. Average solar array energy is around 720 watt-hours after the cleaning event!
Opportunity finished a campaign using the robotic arm on a cobble called "Antistasi." The Moessbauer spectrometer and alpha particle X-ray spectrometer data show that the cobble is very basaltic. On Sol 645 Opportunity drove 22 meters (about 72 feet) south on an outcrop path around "Erebus Crater." This drive pushed Opportunity's total driving distance past the four-mile mark.
Sol-by-sol summaries:
Sol 641 (Nov. 12, 2005): Opportunity unstowed the robotic arm, changed tools to the Moessbauer spectrometer and did a Moessbauer integration on a cobble called Antistasi.
Sol 642: The rover continued the Moessbauer integration on Antistasi up to the afternoon Mars Odyssey pass. It changed tools to the alpha particle X-ray spectrometer and started an overnight integration on Antistasi.
Sol 643: Opportunity changed tools to the Moessbauer spectrometer and started an integration. The rover then monitored dust with the panoramic camera and imaged surrounding cobbles.
Sol 644: The Moessbauer integration on Antistasi continued and panoramic-camera imaging of the surrounding outcrops was conducted.
Sol 645: Opportunity drove about 20 meters (about 66 feet) on an outcrop path so the rover would be able to analyze the outcrops more with the panoramic camera. Also, the panoramic camera was used for studying terrain for future drives.
Sol 646: The rover did untargeted remote sensing.
Sol 647: The plan for this sol is for Opportunity to check its composition and calibration target with the Moessbauer spectrometer, microscopic imager and alpha particle X-ray spectrometer. Also planned are observations of outcrop targets called "Show Low" and "Sedona" with the panoramic camera.
Sol 648 (Nov. 19, 2005): The plan is to conduct Moessbauer-spectrometer integration on the composition and calibration target, and to use the panoramic camera to observe an outcrop target called "Winslow" and a cobble target called "Snowflake."
Opportunity has driven a total of 6,446.45 meters (4.01 miles).