ESA Science & Technology - Sleeping Satellites - Nursing Cluster through Critical Eclipses

Publication date: 15 February 2007

Authors: J. Volpp et al.

Journal: ESA Bulletin
Volume: 129
Page: 26-32
Year: 2007

Copyright: ESA

ESA's fleet of four Cluster satellites was launched in 2000 to investigate the magnetic interaction between the Sun and Earth. Designed to last 3 years, the mission has now been extended to the end of 2009. But the batteries of the satellites are well beyond their design lives and are starting to fail - the power situation first became critical during the long eclipses in September 2006. The battery aboard one could not power the heaters or computer, so new options had to be developed to avoid dangerous low temperatures and to regain control after each eclipse.