|GeoForschungsZentrum Potsdam||Deutsches Raumfahrt-Kontrollzentrum|
CHAMP Bulletin No. 1
July 15, 2000, 12:00 UTC|
July 17, 2000, 08:00 UTC
The geoscientific satellite CHAMP of the GeoForschungsZentrum Potsdam was launched on July 15, 2000 at 11h 59 min 59.628 sec UTC from the cosmodrome Plesetzk (Russia) with a COSMOS-3M launcher precisely into its designed orbit. Immediately after injection, the space operation center Oberpfaffenhofen of the German Aerospace Center DLR took control over the satellite operations. The NASA network of polar ground stations is integrated into the operation for the first 60 hours. After separation of CHAMP from the second stage near Hawaii the first telemetric data were received over the NASA ground station McMurdo (Antarctica) and were transmitted to Oberpfaffenhofen in real time for first check-out. In the subsequent contact with Weilheim, CHAMP was commanded for the first time from the ground with the commands being verified by telemetry. From then onwards, CHAMP operations run nominally at the space operations control center.
The CHAMP data receiving stations of DLR in Weilheim and Neustrelitz and the data preprocessing and archiving system of GFZ in Potsdam are integrated into these activities.
Satellite bus systems
On the first day after launch primarily the satellite operation systems were checked out. The major components show nominal performance. Power supply from the solar generators, the telemetric system and the onboard computer show normal performance. The demanding attitude and orbit control system keeps CHAMP on a firm course. One of the six earth/sun sensors for save mode failed.
The 4 m boom of CHAMP carrying the magnetic field sensors was successfully deployed. Thus the conditions for turning on the magnetic field sensors are fulfilled.
Some of the scientific instruments serve also to supply the satellite operation systems with the necessary observation data. These instruments were first put into operation, namely the vector magnetometer, the CHAMP GPS flight receiver and four star sensors. The vector magnetometer and GPS receiver function properly for navigation purposes. To realize full functionality a number of software optimisations still have to be performed for both instruments.
Today and in the following days the other scientific instruments will be switched on.
The flight operations team, composed of DLR, GFZ and industry experts, has continuously analysed the state of the satellite. After coordination in the team, operation procedures as well as necessary adjustments were performed so that the satellite is now in the Fine Pointing Mode.
CHAMP orbit tracking data are presently recorded by the telemetric and commanding stations Weilheim, Neustrelitz, Spitsbergen and Poker Flat (Alaska), a German radar observation station FGAN (near Bonn) and the satellite onboard GPS receiver. The international laser tracking network is integrated into the tracking of CHAMP. The first results were reported by the SLR station Riga, Latvia.
The CHAMP orbit has been determined with good accuracy already 3 hours after separation.