CLASSIFICATION OF GEOSTATIONARY OBJECTS
ANDEZ and R. JEHN
Mission Analysis Section, ESOC, Robert-Bosch-Strasse 5, 64293 Darmstadt, Germany
(Received 7 June 2001; Accepted 10 September 2001)
Abstract. This paper lists all geostationary and near-geostationary objects contained in ESA’s DISCOS
Keywords: DISCOS database, geostationary objects, libration orbits, two-line-elements
All geostationary objects catalogued in the ESA’s DISCOS Database (Database and Informa-
tion System Characterising Objects in Space) are listed in this document. The main purpose
is to classify all these objects according to different categories. Indeed, six different types
of categories are deﬁned:
• C1: Objects under longitude and inclination control (E-W as well as N-S control) – the
longitude is nearly constant and the inclination is smaller than 0.3
• C2: Objects under longitude control (only E–W control) – the longitude is nearly constant
but the inclination is higher than 0.3
• D: Objects in a drift orbit,
• L1: Objects in a libration orbit around the Eastern stable point (longitude 75
• L2: Objects in a libration orbit around the Western stable point (longitude 105
• L3: Objects in a libration orbit around both stable points.
All objects are selected from the DISCOS Database according to the following criteria:
• Eccentricity smaller than 0.1,
• mean motion between 0.9 and 1.1 revolutions per sideral day, corresponding approxi-
mately to a radius of 42 164 ± 2800 km,
• inclination lower than 20
Produced with the DISCOS Database.
For further information about the method of classiﬁcation, please refer to P. Samson, Classiﬁcation of
Geostationary Objects, MAS WP 420, or contact Dr. R. Jehn, European Space Operations Center (ESOC),
Robert-Bosch-Strasse 5, 64293 Darmstadt, Germany (Tel.: +49-6151-902714; Fax: +49-6151-902625; E-
Space Debris 1, 235–337, 2001.
© 2001 Kluwer Academic Publishers. Printed in the Netherlands.