ASTRID is a microsatellite carrying scientific instruments designed to investigate the near-Earth plasma environment with emphasis on neutral particle phenomena. By making novel measurements of uncharged particles, it will be possible to increase the knowledge of charged particles in the Earth's radiation belts and ring current. The energetic ions in the ring current charge exchange with cold hydrogen atoms in the Earths' exosphere. The resulting energetic neutral atoms (ENA) escape from the ring current. ENA can thus be used to remotely "image" the ring current in order to study the morphology and dynamics of this region. Another important field of study is the outflow of neutrals from the auroral region.
ASTRID marks the first use of the FREJA-C, a generic microsatellite bus which has been developed by the former Space Systems Division (now OHB Sweden) of the Swedish Space Corporation in Solna. The size of the platform box is 420 x 354 x 290 mm. The weight is 27 kg.
ASTRID was successfully launched on January 24, 1995 at 03:54:22 UT from the Russian launch site Plesetsk, using a piggyback arrangement on a COSMOS launch vehicle. The orbit is circular at 1,000 km altitude, inclined 83 degrees to the equator. For an artists impression of ASTRID in space, click here.
For further information about the FREJA-C microsatellite platform, please contact the program manager Anna Rathsman at SSC.
For further information about the scientific project ASTRID, please contact the Solar Terrestrial Physics research programme at IRF.