Space Debris Tracking

According to models, such as MASTER-2005 (Meteoroid and Space Debris Terrestrial Environment Reference) from ESA, there are over 600,000 objects larger than 1 cm in diameter in orbit around the Earth. About 13,000 objects larger than 5 cm are continuously monitored by the US Space Surveillance System. In 2009, the Joint Space Operations Center of the United States Strategic Command knew of more than 18,500 man-made celestial bodies.

The United States Defense Department keeps track of most space debris because it must be possible to distinguish between a rocket and space debris in the event of a missile attack. In 1987, there were 7,000 recorded objects larger than 10 cm. According to the NASA Orbital Debris Program Office, by 2012 that number had increased to more than 21,000. They estimate that there are about 500,000 pieces from 1 to 10 cm in size in orbit and more than 100 million pieces smaller than 1 cm.

Within the framework of measurement campaigns, sporadic measurements are carried out with radar systems and telescopes in order to at least statistically record smaller objects and to validate space debris models such as MASTER. This is achieved by bistatic radar with the Goldstone radio telescope up to 2 mm in diameter for objects in low-Earth orbit (LEO). For geostationary orbit (GEO), optical telescopes have the smaller limit size: 10 cm is reached by the ESA Space Debris Telescope at the Teide Observatory on Tenerife.

Another source of information on the distribution of space debris is returned satellite surfaces. These include the solar cells of the Hubble Space Telescope. On the latter, a large number of impact craters were recorded and evaluated. Spectroscopic analyses enabled conclusions to be drawn about the composition and thus possible sources of the impacted objects.

Space Debris Detection

The detection of space debris can be done from the ground using optical telescopes or radar. Some radars can detect particles in the millimetre range in low orbits. However, accurate measurement of the orbital parameters and continuous tracking of the objects is only possible for diameters from 5 cm in LEO and 50 cm in GEO. The orbits of these objects are continuously tracked by the American Space Surveillance System and their orbital elements are published in an object catalogue. Currently, this catalogue contains about 13,000 objects, but only the orbital data for about 9600 objects are available to the public. This leaves in-situ measurements as the only possibility to determine the population and orbital parameters of smaller particles. Several detector concepts have already been tested for this purpose. The best-known European detector concepts are the DEBIE detector and the GORID detector (identical to the Galileo and Ulysses detectors). Both detectors determine the impact energy of a high-speed particle via the composition of the plasma created by the impact. The electrons and ions in the plasma are separated from each other with electric fields and the respective voltage is measured with charged grids. The mass and velocity of the impacted particle can be determined from the shape and time course of the voltage pulses using calibration curves recorded on the ground. In addition to the pure plasma measurement, the DEBIE sensor also measures the impact pulse via piezo elements, so that there is a signal for comparison with the plasma measurement. A plan to use the Large Area Debris Collector (LAD-C) on the ISS to capture and analyse space debris was abandoned in 2007.

Space Debris Catalogues

The catalogues on artificial satellites, for example NORAD, are limited to intact objects. The debris created when they break apart is recorded in separate space debris databases. One, like NORAD, is maintained by USSTRATCOM. It is also the basis for ESA's DISCOS (Database and Information System Characterizing Objects in Space) collection.

German Experimental Space Surveillance and Tracking Radar (GESTRA).

The German Aerospace Center (DLR) has had the GESTRA space surveillance radar developed to monitor space objects in low-Earth orbit. The measurement data obtained will be processed at the Space Situation Centre operated jointly by DLR Space Management and the German Air Force in Uedem (Lower Rhine). The system is scheduled to begin operational service in early 2021.

Long Duration Exposure Facility (LDEF).

The LDEF satellite was an experiment to study the long-term effects of a space environment. Although planned to be much shorter, the satellite remained in orbit for almost six years before it was recovered and returned to Earth by mission STS-32. Apart from many damages visible only microscopically, there was also one visible to the naked eye. Examination of the satellite yielded a great deal of information about space debris and micrometeorites.


Visit our media section for a complete overview.


International Space Station
Orbital Debris
Space Debris
Space Debris Mitigation
Space Junk
Space Pollution
Space Trash
Space War
Space Waste


DeepDove: Space Network (2021-09-21). Space Debris | Space Debris Tracking. Retrieved , from




This page was last changed on 2021-09-21.