Spirit continues slipping in sandy terrain but forges ahead using crafty techniques such as switchbacking and creating a zigzag course.
Sol-by-sol summaries:
Sol 442 (March 31, 2005): Spirit drove successfully uphill for 12.6 meters (41.3 feet). At the start of the drive, Spirit averaged a 42.7 percent slip, but this quickly improved. In the last 3 meters (10 feet), Spirit only slipped
14.6 percent. The average slip for the drive was 17.6 percent.Sol 443: Spirit performed 4 hours of targeted remote sensing, which included panoramic camera images and miniature thermal emission spectrometer readings.
Sol 444: The team planned a long drive through tricky terrain with switchbacks to help Spirit ascend. Spirit drove approximately 8.8 meters (29 feet).
Sol 445: Spirit performed remote sensing in the afternoon, including an image brightness test with the navigation camera. The goal of this test is to establish the latest time when Spirit can take images prior to sunset and still have viable images to use in the rover drivers' planning tools. The image analysis may allow the rover team to use later times for post-drive imaging and thus increase Spirit's drive time every sol. This is part two of the testing.
Sol 446: Spirit and Opportunity use NASA's Mars Odyssey orbiter as their main communications link between Mars and Earth. On April 2, Odyssey entered "safe mode," which is a protective state a spacecraft automatically enters when onboard fault protection software instructs the spacecraft to disregard its onboard sequence of commands and wait for instructions from the ground. As a result, relay communication with the rovers was suspended, and Spirit did not receive any data from sols 444 and 445. With an unknown status of the rover after its drive, the Spirit team restricted rover operations to remote sensing.
Sol 447: The Odyssey flight team scrambled to recover the orbiter, but it remained in a safe state, not yet available to support relay communications. Spirit received very little information from its "direct-to-earth" communications link, so the rover team planned another basic remote sensing sol, which generated little data.
Sol 448 (April 7, 2005): Spirit performed additional remote sensing, including panoramic camera and navigation camera imaging. The Odyssey team brought the orbiter back on-line, the Spirit team received all imaging needed for continuing to drive, and team members are planning to drive on sol 449 with a new appreciation for their orbiting partner! The Odyssey team is investigating the cause behind the fault protection software sending the orbiter into safe mode.