Results on the optimal in-orbit manoeuvres of an observation satellite

Abstract The linearized theory of optimal orbit corrections (minimization of characteristic velocity) is applied to various manoeuvres of an observation satellite: (i) adjustment of the survey orbit after injection, (ii) unique or repeated fly-over of a given point of the Earth, (iii) transfer to a safeguard orbit of maximum altitude, with maintenance of Sun-synchronism. The method permits mixed (i.e. simultaneous in-plane and out-of-plane) corrections; these corrections are often done successively, hence with some loss. The performance loss due to thrust spreading is brought to light for some cases. The original form taken by the fly-over condition makes the corresponding study rather delicate. The out-of-plane manoeuvres are interesting only for short durations. The cost decreases on average with the duration.