http://www.marsdaily.com : Spirit Catching More Rays
by Staff Writers
Pasadena CA (JPL) Jun 21, 2010
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.
When the batteries recover to a sufficient state of charge, Spirit will wake up and begin to communicate.
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.
The southern winter solstice was on May 13, 2010, so solar energy levels and temperatures should be improving.
Total odometry is unchanged at 7,730.50 meters (4.80 miles).