Recent examples
The satellite was at the end of its life and its state of health was unpredictable, with the risk that mission managers might lose control of it completely.
Although Spot 1’s design predated the IADC guidelines, CNES decided to apply them anyway, as there was still enough propellant on board to modify the satellite’s orbit in line with IADC requirements.
Hauteur des vidéos : 300px
Nom de la première vidéo : Deorbiting Spot-1
Texte de la première vidéo :
Credits: CNES
Vignette de la première vidéo (108px):
Url externe de la première vidéo : http://www.cnes-multimedia.fr/video/flash/desorbit_spot1.flv
Image d'attente de la première vidéo :
From its 800-km orbit, Spot 1 was therefore brought down into an elliptical orbit of about 570 km at perigee and 800 km at apogee, where it would fall back into the atmosphere in less than 25 years.
Objective accomplished: Spot 1 will re-enter and burn up in the atmosphere within about 16 years, whereas it would have remained in orbit for 2 centuries if CNES had done nothing.
Satellite Telecom 2A. Credits: CNES/ill. D.DUCROS
CNES also successfully disposed of the Telecom 2A and 2b geostationary satellites at the end of their life, boosting them into a graveyard orbit above the protected region and then passivating their systems to avert any later risk of explosion.
Venting propellant is especially tricky, as the formation of gas bubbles in the thruster nozzles can send the satellite out of control. Extra care therefore had to be taken so as not to lose precious kilometres gained in altitude during reorbiting.
Other deorbiting solutions are also in development for satellites controlled by CNES.
