Obtaining geostationary orbit from an off-nominal low transfer orbit.

A theory for optimal apogee raising maneuvers for geostationary spacecraft injected in a low tranfer orbit and equipped with a solid propellant apogee boost motor is developed. These maneuvers are made by hydrazine thrusters before the apogee boost motor firing. The decrease in propellant needed for station acquisition amounts to about 15-19 m/s for each 1000 km the apogee is below normal compared with the solution of only using these thrusters after the firing.