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. While sleeping, the rover will use the available solar array energy to recharge her batteries.
The rover electronics module (REM) is expected to get colder than ever before. When the batteries recover to a sufficient state of charge, Spirit will wake up and begin to communicate over X-band and Ultra-High Frequency (UHF).
There is the additional risk that the rover may trip a mission clock fault.
If that happens, the rover would remain asleep until the batteries have recharged sufficiently and there is enough sunlight on the solar arrays to wake the rover.
With the passing of the southern winter solstice (on May 13, 2010), solar energy levels and temperatures should be improving.
Total odometry is unchanged at 7,730.50 meters (4.80 miles).