New Radar To Detect Space Debris
By Ron Grunsby
The European Space Agency (ESA) has deployed a new radar system in Spain to test ways to find orbital debris that may pose a danger to space navigation in low-altitude orbits. Installed near Santorcaz, about 30 km from Madrid, the radar will be used to create debris warning services in an effort to improve safety for European satellite operators. Detecting space debris early gives satellite operators the opportunity to make avoidance maneuvers when necessary.
The radar can be reconfigured based on test results, allowing its performance to be optimized over time. Acceptance and validation tests will start in mid-November.
The radar was built under a €4.7-million contract signed in 2010 between the ESA’s Space Situational Awareness (SSA) program office and Spain’s Indra Espacio S.A. Indra Espacio is handling the design and development of the transmitter, and the Fraunhofer Institute for High Frequency Physics and Radar Techniques in Germany is developing the receiver.
The transmitter and receiver are within a few hundred meters of each other, which is known as a monostatic design. According to an article by Fraunhofer, the system uses an electronically steerable, inertia-free antenna that can be positioned very quickly and observe numerous objects at the same time; the plan is to have 15,000 to 20,000 objects on the radar for at least 10 seconds every day. A phased array antenna is used as the sensor and can capture radar signals reflected by satellites and space debris in up to eight directions simultaneously. It will be able to detect pieces of debris as small as a few cm in diameter in the low Earth orbit at an altitude of between 200 and 2,000 km.
An additional €4 million contract was signed in September 2012 between the ESA and France’s ONERA (Office National d’Etudes et Recherches Aérospatiales) research center to build a ‘bistatic’ test radar, in which the transmitter and receiver are separated by several hundred kilometers.
In the future, the ESA plans to use a set of optical telescopes to watch space debris at higher-altitude orbits. The radars and telescopes will be improved over time to further enhance satellite safety.