Spirit remains silent at her location called “Troy” on the west side of Home Plate. No communication has been received from the rover since Sol 2210 (March 22, 2010).
It is likely that Spirit has experienced a low-power fault and has turned off all sub-systems, including communication and gone into a deep sleep, trying to recharge her batteries. There is the additional risk that the rover may trip a mission clock fault.
If that happens, the rover would lose track of time and remain asleep until there is enough sunlight on the solar arrays to wake the rover, a state called “Solar Groovy.”
When the rover wakes from a mission clock fault, she would only listen. So starting on Sol 2333 (July 26, 2010), the project implemented a new procedure to address the possible mission clock fault.
Each sol, the Deep Space Network mission controllers send a set of X-band beep commands, called “Sweep and Beep.” If the rover has experienced a mission clock fault and is awake during the day, the rover will be listening during brief, 20-minute intervals each awake hour.
Because of the possible clock fault, the timing of these 20-minute listening intervals can’t be known. So the project will fill the likely awake period with multiple “Sweep and Beep” commands.
If the rover hears one of these commands, it will respond back with an X-band beep signal, telling them she is there and allowing them to investigate the state of the rover further.
Although the project is using this new strategy now, a response from Spirit is not expected for some time, as the season is still very early spring on Mars.
Total odometry is unchanged at 7,730.50 meters (4.80 miles).