US Air Force's Combined Release and Radiation Effects Satellite

Mission Briefing :

CRRES was a joint NASA / DOD undertaking originally built for STS launch. It was subsequently modified for launch on an Atlas Centaur, and was boosted into orbit on July 25th 1990 3:21 pm EDT. The spacecraft suffered a critical power subsystem failure in October 1991, having traversed a substantial fraction of near Earth local time (200K gif of coverage), performing valuable studies of Earth bound radiation belts up to geostationary orbit. The mission carried payload instrumentation from the Mullard Space Science Lab's Space Plasma Physics Group. This instrument was the Low Energy Plasma Analyser (LEPA).

Objectives :

Operations supported three major objectives :

Orbital Data

The spacecraft operated in a highly elliptical geosynchronous transfer orbit (upto 6.6 Re).

35,768 x 350 km, inc 18 deg, period 10.5 hours, decreasing to 9.5 hrs Oct 91.

The Mullard Space Science Lab's Space Plasmas group flew an experiment investigating thermal plasma in the eV to 40 keV range, gathering data on electron and ion distributions in energy, azimuthal, and polar angle - LEPA.


Surviving Radiation in Space, Andrew Coates, New Scientist, pg 42, 21st July 1990

Combined Release and Radiation Effects Satellite, A.L.Vampola, Journal of Spacecraft and Rockets, Vol 29, No. 4, July-August 1992.

* Low Energy Plasma Analyser

* Mullard Space Science Lab. * Space Plasma Physics Group.

This page is maintained by :-
Nick Flowers (, +44 1483 274111
Space Plasma Physics Group, Mullard Space Science Laboratory,
Holmbury St. Mary, Dorking, Surrey, RH5 6NT, United Kingdom

Adapted in part from AFGL documentation.
Version 2.2: Updated March 8th, 1995, 1856 GMT, NJF.
e Ariane-5 explosion and the subsequent damage to the PEACE instruments.


The Cluster-II missi