fenêtre de lancement

OBS: fenêtre de lancement : terme uniformisé par le Groupe de travail de la terminologie de RADARSAT-2 (GTTR).

CONT: For launches into Earth orbit the main constraints are the desired orbit, the point of injection into that orbit, and the possibility of a collision with other orbiting spacecraft or orbital debris. For launches to interplanetary trajectories, the time of launch is constrained by the relative positions of the planets, at the time of both launch and encounter (i.e. the spacecraft must be aimed at a point in space that the planet will have reached by the time of encounter). A spacecraft launched outside the launch window would require more propellant and/or more time to reach its target.
OBS: There are also geometric windows (e.g., restrictions in launch azimuth).