Spirit drove to an outcrop informally named "Kansas" to prepare for a series of robotic arm activities on a target called "Kestrel."
Engineers tested a new UHF-only operation for Spirit. Throughout the mission, NASA's Mars Odyssey orbiter has been successfully receiving data from the rovers using its UHF (ultra-high frequency) antenna and relaying the data to Earth. In the new UHF-only operation, the team attempted to demonstrate how Spirit could also receive commands from Mars Odyssey via UHF antennas.
Spirit usually receives commands through its high gain antenna, which collects radio waves in the X-band sent directly from Deep Space Network antennas on Earth.
During sols 641 through 645, Mars Odyssey attempted both to send commands to Spirit and to collect data from Spirit. The commanding was successful on sols 640 and 645, but on sol 644, during receipt of the command bundles, Spirit's computer reset due to flight software difficulties with handling the command loads at the rate of 8 kilobits per second. As a result, all the active sequences were deactivated and Spirit went to automode.
On sol 646, Spirit recovered from automode and continued the robotic arm work on Kestrel.
Sol-by-sol summaries
