posted November 30, 2012
On Oct. 6, 2007, during the 24th year of its three-year expected lifetime, Landsat 5 autonomously halted imaging operations due to a large spike in the temperature of its battery no. 2. The spacecraft continued to function on its one remaining battery (no. 3) long enough for ground engineers to reduce the spacecraft electrical load. There was deep concern at USGS that this was the end of Landsat 5 operation.
After a meeting to discuss a plan forward, USGS consulted an Aerospace battery expert, Boyd Carter, who developed a new approach for bringing battery no. 2, and possibly long-abandoned battery no. 1, back online to allow resumed operations. The first phase of his approach was to allow the spacecraft to stabilize at its current settings and prepare autonomous switching routines for later phases. Then a series of tests was performed that succeeded in bringing battery no. 2 back online. The Landsat 5 batteries have returned to their preanomaly state with battery no. 2 doing more work than battery no. 3, which is surprising considering that battery no. 2 lost a cell. Landsat 5 began limited imaging in mid-January 2008, and returned to nearly full capability by early February 2008.