New images from an experimental satellite, programmed to decide for itself how to carry out its mission, have been released by the European Space Agency (ESA).
Scientists on Earth wishing to image certain parts of the planet simply send their requests to the PROBA (Project for On Board Autonomy) satellite. Its onboard computer system then determines how best to schedule all its tasks.
PROBA contains the most powerful computer system ever built into a satellite launched by ESA. But it measures just 60cm x 60cm x 80cm and weighs less than 100 kg. Most existing Earth-imaging satellites are considerably larger and also rely on a team of ground controllers.
Max Meerman, principal engineer with the UK company Surrey Satellites, says one advantage is that instructions can be sent to the satellite from a number of different command uplink centres around the world and that these would not need to be in contact with each other. But he adds that software problems in autonomous craft can be much more difficult to repair from Earth.
PROBA’s onboard computer system maintains the satellite’s position in orbit by communicating with Global Positioning System (GPS) satellite’s. Another instrument references the stars to fix the position of PROBA’s camera correctly. The satellite will also monitor factors such as showers of space junk and bursts of radiation for research purposes.
PROBA was launched in October 2001 by an Indian PSLV launch vehicle.