Mitigation Method of Spacecraft Momentum by Solar Radiation Pressure

摘要

THE multipurpose geostationary satellite, COMS (Communica-ntion, Ocean, and Meteorological Satellite), was developed forncommunication, ocean, and meteorological missions in Korea. Thisnspacecraft has a single solar array, due to payload requirements fornocean and meteorology missions. GOES (Geostationary OperationnEnvironmental Satellite) for meteorology imaging is also a satellitenwith a single solar array. An on-station satellite is influencednby disturbance torques. Disturbance torque includes aerodynamicntorques, magnetic torques, torques due to solar radiation pressure,nand gravity-gradient torques. Among disturbance torques, aero-ndynamic torques, magnetic torques, and gravity-gradient torquesnare relatively small compared with torques due to solar radiationnpressure in geostationary satellites such as COMS. Because of con-nfiguration, an asymmetric satellite has a problem with momen-ntum accumulation due to solar radiation pressure when comparednwith a symmetric satellite [1–3]. The accumulated wheelmomentumnincreases during the operation of a single-solar-array satellite. Thus,nperiodic momentum dumping is required to maintain a level ofnmomentum in the reaction wheels of satellite. GOES deploys a solarnsail boom to reduce the momentum increase due to its asymmetricnbody shape. A solar sail boom plays the role of equivalent weight.nHowever, if there is insufficient space for establishing a solar sailnboom, thismethod cannot be used, because a deployment equipmentnstructure and a solar sail boom cannot be installed on the oppositenside of the solar array [4]. In this Note, methods of reducingnmomentum dumping are studied. The proposed methods use solarnradiation pressure and mass-center portion management. Thesenmethods contribute to resolving themomentumdumping problemin single-solar-array satellites, which lack sufficient space to establishna solar sail boom.