EUROPEAN SPACE AGENCY
EUROPEAN SPACE OPERATIONS CENTRE
GROUND SYSTEMS ENGINEERING DEPARTMENT
Mission Analysis Office
CLASSIFICATION OF GEOSYNCHRONOUS OBJECTS
This is a status report on geosynchronous objects as of the end of 2006. 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 30 deg) is analysed. From 911 objects for which Two-Line-Elements (TLE) are available, 309 are controlled inside their longitude slots, 448 are drifting above, below or through GEO, 147 are in a libration orbit and 7 whose status could not be determined (status of Dec. 2006). Furthermore, there are 45 controlled satellites and 165 uncontrolled objects without TLEs (of which 68 have not been catalogued). Thus the total number of known objects in the geostationary region is 1121, out of which 354 are controlled, 760 are uncontrolled and 7 could not be classified. Additionally there are 138 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 1121.
During 2006 sixteen spacecraft reached end-of-life. Seven of them were reorbited following the IADC recommendations. Seven were reorbited with an insufficient increase in altitude. One spacecraft could not perform a proper end-of-life disposal manouevre due to a catastrophic failure and one spacecraft was abandoned without a disposal manoeuvre. Two rocket bodies were inserted into orbits crossing the geostationary altitude which is a clear violation of the IADC guidelines.
If you detect any error or if you have any comment or question please contact
Dr R. Jehn
European Space Operations Center
64293 Darmstadt, Germany