NASA’s GRACE (Gravity-Recovery And Climate Experiment) mission has come to an end after well exceeding its original five year minimum design life following its launch in 2002. The two 487 kg GRACE spacecraft GRACE 1 & 2 which were built by Astrium (now Airbus Defence and Space) were flown in tandem 500 km apart to take precise measurements of the Earth’s gravity field and ionosphere.
Artist’s impression of GRACE Courtesy: NASA
In September, GRACE 2 suffered another cell loss in its battery (the eighth out of 20) and it became apparent that the spacecraft would soon run out of power if any more losses occurred. Hence it was decided to retire both spacecraft in November. This retirement date was brought forward when NASA announced on 27 October that the mission was at an end when it became apparent that the remaining battery capacity would not be sufficient to operate GRACE 2’s science instruments and telemetry transmitter.
