Satellite propulsion and power system

A thruster for station keeping and attitude control of a spacecraft which also has an apogee engine which is used for the apogee kick phase of a mission, said thruster comprising:

• a first tank of a non-cryogenic fuel consisting of essentially pure hydrazine which is in a liquid state at ambient temperature;
• a second tank containing a non-cryogenic oxidizer which is in a liquid state at ambient temperature, said oxidizer being nitrogen tetroxide;
• said hydrazine tank and oxidizer tank supplying fuel to the apogee engine during the apogee kick phase of the mission of the spacecraft;
• said station keeping and attitude control thruster being fed by the same hydrazine and oxidizer tanks during station keeping and attitude control phases of the mission of the spacecraft, said thruster including:
• a first body defining a first reaction chamber having therein a catalytic bed of decomposition material;
• a second body having an inner surface defining a second reaction chamber;
• means for feeding the liquid hydrazine from the tank thereof to the first reaction chamber to react exothermically with the catalytic bed of decomposition material and produce a first group of reaction gases, the reaction gases flowing from the first reaction chamber into the second reaction chamber and heating the second body;
• at least one passageway formed in the second body, said passageway having an inlet and an outlet, said inlet being coupled to receive the non-cryogenic oxidizer while in a liquid state from the oxidizer tank, with the liquid oxidizer flowing through a first portion of the passageway to receive sufficient heat from the second body to initially transform a fraction of the non-cryogenic liquid oxidizer to a heated gas phase, said oxidizer continuing to flow through other passageway portions to receive sufficient heat from the second body to substantially completely transform the oxidizer to a gas phase, the phase change of the oxidizer from liquid to gas serving to cool the thruster during low thrust burns for station keeping and attitude control maneuvers of the spacecraft;
• and
• means for feeding the gaseous oxidizer from the outlet of the passageway into the second reaction chamber to react as a gas with the reaction gases flowing from the first chamber to provide sufficient energy to perform station keeping and attitude control of the spacecraft.