23606 - CERISE

CERISE is a French microsatellite of 50 kg mass and was launched by an Ariane rocket from Kourou in French Guiana at 17:23 UT. It is to eavesdrop on weak HF communications and to carry out broadband radiometric measurements. Initial orbital parameters were period 98.1 min, apogee 675 km, perigee 666 km, and inclination 98.0 deg.

After one year of operation in space, Cerise was observed to undergo a sudden change in attitude, tumbling rapidly end-over-end in its 700 km polar orbit. Initial investigations concluded that the icrosatellite had collided with a piece of space debris. This was the first such collision to be observed.

Subsequent observations and analysis by the UK Space Track Network and NASA confirmed the collision in orbit between Cerise and a piece of debris on 24 July 1996. The debris appeared to have impacted the stabilization boom, which extended 6 m from the main body of the spacecraft, at over 14 km/s (31,000 miles/hour).

Despite the impact, Cerise and its payloads continued to work normally under full ground control. Mission control engineers reprogrammed the microsatellite's advanced on-board computer with new attitude control software which reoriented the spacecraft, relying solely on the on-board electromagnets, allowing it to continue its mission.

Facts in Brief

Launch Date: 1995-07-07
Launch Vehicle: Ariane 4
Launch Site: Kourou, French Guiana
Mass: 50.0 kg