EUROPEAN SPACE AGENCY
EUROPEAN SPACE OPERATIONS CENTRE
GROUND SYSTEMS ENGINEERING DEPARTMENT
Mission Analysis Office

CLASSIFICATION OF GEOSYNCHRONOUS OBJECTS
ISSUE 8
by C. Hernandez and R. Jehn
Produced with the DISCOS Database

February 2006
ESOC Robert-Bosch-Str. 5, 64293 Darmstadt, Germany

This is a status report on geosynchronous objects as of the end of 2005. Based on orbital data in ESA's DISCOS database the situation near the geostationary ring (here defined as orbits with mean motion between 0.9 and 1.1 revolutions per day, eccentricity smaller than 0.1 and inclination below 20 deg) is analysed. From 893 objects for which Two-Line-Elements (TLE) are available, 305 are controlled inside their longitude slots, 433 are drifting above, below or through GEO, 145 are in a libration orbit and 10 whose status could not be determined (status of Dec. 2005). Furthermore, there are 39 controlled satellites and 157 uncontrolled objects without TLEs (of which 66 have not been catalogued). Thus the total number of known objects in the geostationary region is 1089, out of which 344 are controlled, 735 are uncontrolled and 10 could not be classified. Additionally there are 103 orbits listed in this report for unidentified objects. Some of those probably belong to objects where no recent TLEs are available but which are already included in the total number of 1089.

During 2005 eighteen spacecraft reached end-of-life. Ten of them were reorbited following the IADC recommendations. Three were reorbited right at the border of the 200 km protected zone around GEO and three were reorbited with an insufficient increase in altitude. Two spacecraft could not perform a proper end-of-life disposal manoeuvre due to catastrophic failures.

Dr R. Jehn
European Space Operations Center
Robert-Bosch-Str. 5
64293 Darmstadt, Germany
Tel: +49-6151-902714
Fax.: +49-6151-902625