THE FREJA PROJECT

Freja is a joint Swedish and German scientific satellite project to study the interaction between hot magnetospheric plasma and the topside atmosphere/ionosphere. This interaction leads to a strong energization of magnetospheric and ionospheric plasma and an associated erosion and loss of matter from the terrestrial atmosphere. Using novel plasma instruments and a high data rate Freja have provided a number of ''firsts'' in high resolution plasma diagnostics from satellites. Freja's high spatial/temporal resolution permits studies of meso- and microscale phenomena in the 100-m range for particles and in the 10-m range for electric and magnetic fields. The Freja satellite was successfully launched on October 6, 1992 into an orbit with 63-degrees inclination, an apogee of 1750 km and perigee of 600 km.