ESA radar will track space debris

27 July 2010 | By Stephen Harris

The system will be able to identify objects as small as 5cm in diameter in lower orbits with radar, and larger objects at heights of up to 36,000km (geostationary orbit) using optical telescopes.

The radar is part of ESA’s Space Situational Awareness (SSA) programme and will free European countries from dependence on American data, SSA ground segment manager Gian Maria Pinna told The Engineer.

‘We don’t have any system like this in Europe at the moment and our tracking system relies on US data and national assets in France and Germany,’ he said.

‘We are moving towards a federation of assets and trying to use what is already there. But we don’t have the capability in Europe to carry out property surveillance of space debris in order to be non-dependant on external sources.’

‘The building of a catalogue of debris today in Europe is difficult to do because the current radars are operating to another frequency that does not allow us to go to the resolution level we need.’

The radar will provide information for ESA and individual member states and companies. ‘The European Union is also very interested in this because it would give protection to European satellites,’ Pinna added.

SSA was launched at the start of 2009 as a way of monitoring objects such as inactive satellites, discarded launch stages and fragmentation debris satellites, as well as space weather and natural near-Earth objects that could potentially impact the planet.

There are an estimated 500,000 pieces of space debris between 1cm and 10cm in diameter orbiting the Earth, and around 19,000 pieces larger than 10cm, according to NASA.

Spanish technology firm Indra Espacio will design the system and build a demonstrator radar, as well as find a suitable location within an ESA member country. There are several good potential sites in Germany but other countries are being considered, according to Pinna.

The development of the radar receiver will be subcontracted to the Fraunhofer Institute for High Frequency Physics and Radar Techniques in Germany.

The demonstrator will be based on a monostatic radar model, where the transmitter and receiver are co-located, but ESA hasn’t ruled out a bistatic model where the receiver is in a different location and the system can transmit constantly.

Following the €50m (£42m) preparatory phase of the project, ESA will decide whether to continue with the full project at a ministerial council meeting sometime in 2012. Initial industry estimates for the total cost of the project are around €200m.

The growing amount of man-made junk orbiting the Earth is prompting calls for a cosmic clean-up. Click here to read more.