France: European Space Agency’s (ESA) earth-observing satellite, Envisat, has moved to a lower orbit in order to conserve fuel and extend its life by three years and is once again delivering invaluable data to thousands of scientists.
In order for the satellite to stay operational another three years, engineers from ESA’s European Space Research and Technology Centre (ESTEC) in Noordwijk, The Netherlands, came up with a plan to minimise fuel use by moving it to a lower orbit so it would no longer have to correct for the gradual change in orbit inclination during this period.
The Envisat orbit change project, called ‘Envisat 2010+’, to lower it from about 800 km to about 783 km began on the morning of 22 October. The 8000-kg satellite was lowered by about 10 km with two 28-minute repositioning moves. Following another two manoeuvres on the evening of 26 October, the satellite was lowered an additional 7 km, reaching its new final altitude.
Envisat’s instruments were slowly switched back on starting on 27 October, and the satellite is now gradually resuming its normal activities.
ESA Envisat Mission Manager Henri Laur said: “The first images acquired from the new altitude confirm that the satellite is in good health and that the manoeuvres have been successful.
Envisat, launched in 2002, has a unique combination of 10 different instruments that collect data about Earth’s atmosphere, land, sea and ice – providing scientists with the most detailed picture yet of the state of our planet.