초록 ▼

Spacecraft stationkeeping and momentum-dumping methods are facilitated by the use of selected diagonal pairs of thrusters which are positioned adjacent to nadir or antinadir spacecraft faces. The methods maintain an elliptical Sun-synchronous orbit, counter triaxiality forces and facilitate momentum

Spacecraft stationkeeping and momentum-dumping methods are facilitated by the use of selected diagonal pairs of thrusters which are positioned adjacent to nadir or antinadir spacecraft faces. The methods maintain an elliptical Sun-synchronous orbit, counter triaxiality forces and facilitate momentum-dumping of momentum and/or reaction wheels. They are particularly suited for inclined orbits.

대표청구항 ▼

[ I claim:] [1.] A method of stationkeeping a spacecraft, comprising the steps of:providing said spacecraft with first and second pairs of thrusters adjacent a selected one of a nadir or an antinadir face of said spacecraft wherein said first thruster pair comprises a northwest and a southeast thrus

[ I claim:] [1.] A method of stationkeeping a spacecraft, comprising the steps of:providing said spacecraft with first and second pairs of thrusters adjacent a selected one of a nadir or an antinadir face of said spacecraft wherein said first thruster pair comprises a northwest and a southeast thruster and said second thruster pair comprises a northeast and a southwest thruster;placing said spacecraft in a Sun-synchronous elliptical orbit which has an initial eccentricity vector aligned with a Sun line between said spacecraft and a Sun, solar pressure from said Sun thereby generating a solar-pressure eccentricity vector which leads said Sun line by substantially ninety degrees;when said spacecraft is positioned at a longitude where it is exposed to an eastward triaxiality force, applying a westward force to said spacecraft in an orbital region which leads said Sun line by substantially ninety degrees to counter a drift acceleration caused by said eastward triaxiality force and to generate a westward-force eccentricity vector which lags said Sun line by substantially ninety degrees and opposes said solar-pressure eccentricity vector, said westward force applied with a selected one of said first and second pairs of thruster pairs; andwhen said spacecraft is positioned at a longitude where it is exposed to a westward triaxiality force, applying an eastward force to said spacecraft in an orbital region which lags said Sun line by substantially ninety degrees to counter a drift acceleration caused by said westward triaxiality force and to generate an eastward-force eccentricity vector which lags said Sun line by substantially ninety degrees and opposes said solar-pressure eccentricity vector, said eastward force applied with said selected thruster pair.