The Freja Mission, Reprinted from SPACE SCIENCE REVIEWS; 70:3-4, 1995

Freja is a joint Swedish and German satellite, launched on October 6, 1992 and orbiting at 600--1750 km, covering the lower part of the auroral acceleration region. It has been designed to provide high-resolution measurements (both temporal and spatial) of auroral plasma characteristics. The high telemetry rate, together with the 15 Mbyte distributed on-board memories allow Freja to resolve meso and micro-scale phenomena in the 100 m range for particles and 1--10 m range for electric and magnetic fields. The UV imager resolves auroral structures of 1 km size at a time resolution of one image every 6 s. The novel plasma instruments are orders of magnitude better than any that have gone before.
The Freja Mission is about the scientific objectives, instruments and platform itself. Detailed descriptions are given of the instrumentation and the first data acquired. It is one of the very few books to contain such material in a single volume, relating the instruments' design with their in-flight characteristics.
For space engineers and other researchers interested in space science.

The Freja Science Mission.- The Freja Ultraviolet Imager.- The Electron Beam Instrument (F6) on Freja.- Magnetic Field Experiment on the Freja Satellite.- The Double Probe Electric Field Experiment on Freja: Experiment Description and First Results.- The TESP Electron Spectrometer and Correlator on Freja.- The Freja F3C Cold Plasma Analyzer.- The Freja Hot Plasma Experiment — Instrument and First Results.- The Freja Wave and Plasma Density Experiment.- Plasma Characteristics Determined by the Freja Electric Field Instrument.