EUMETSAT’s polar-orbiting satellite Metop-C is now flying in its final operating orbit, in a tri-star constellation with Metop-A and –B, after a recent series of manoeuvres.
Metop-C was launched from the European Space Port in Kourou, French Guiana, on 7 November.
Mission Control Systems Manager Gareth Williams said three separate orbit adjustments, using 14.9kg of the satellite’s 297kg of hydrazine fuel, were performed.
“Although these were called ‘drift slow’ and ‘drift stop’ activities, the nature of orbital mechanics meant that each of these manoeuvres actually involved speeding up the satellite in orbit,” Gareth said.
“The first manoeuvre was relatively small and slightly changed Metop-C’s orbit, allowing us to calibrate the on-board thrusters for the following, larger manoeuvres.
The next day, the orbital drift of Metop-C relative to its sibling spacecraft was significantly reduced by carrying out a two-burn drift slow manoeuvre, involving two separate thruster firings spaced half an orbit apart.
The final change was a drift stop manoeuvre which lifted Metop-C to its final operating altitude about 817km above the Earth’s surface.
“That is where it will stay for the duration of its operational life,” Gareth said, “although it’s possible the spacing relative to Metop-A and –B will change in the future.”
EUMETSAT takes the issue of space debris very seriously. When the Metop satellites are no longer able to be used operationally, they will be moved to a disposal orbit that will eventually result in their destruction by re-entry into the Earth’s atmosphere, nominally within 25 years of reaching the end of their operational lifetime.