First Cluster apogee burn completed
17 July 2000The long, complex process required to elongate the orbits of the first twoCluster spacecraft has begun.The Cluster mission control centre at the European Space Operations Centre(ESOC) in Darmstadt, Germany, has confirmed that the apogee raising manoeuvre #1was completed successfully early this afternoon.
At 13.21 CEST today, the main engine of the Cluster FM 6 (Salsa) spacecraft ignited, followed just one second later by the main engine on FM 7 (Samba). Both engine burns took place when the spacecraft were near the perigee (lowest point) of their orbits, 244 km above the Earth.
Each 10 minute 33 second burn was intended to stretch the spacecraft orbits, raising their apogee (highest point) from 18,067 km to 24.442 km. Preliminary data received from the Kiruna ground station in Sweden at 13.38 CEST confirmed that both burns had gone as planned.
This was the first of four apogee raising manoeuvres that are scheduled for both Cluster spacecraft over the coming four days. The next burns are provisionally set for 8.34 (FM 6 - Salsa) and 8.38 (FM 7 - Samba) tomorrow morning.
By 20 July, the first Cluster pair should be dancing together along highly elliptical orbits of approximately 18,000 x 121,000 km, which means they will then be travelling almost one third of the distance to the Moon.
The fifth and final main engine burns will then alter the inclinations of their orbits from 64.9 degrees to 90.6 degrees, transferring them to orbits that pass over the Earths poles.