A spacecraft sail design that could de-orbit a satellite from low-Earth orbit (LEO) using atmospheric drag is to be tested next year.
Fired by sounding rocket into a suborbital flight, the payload will test the sail's deployment technique. Deployment is also dependent on the way the sail is packed, which is a major challenge as every kilo of satellite mass would need a corresponding square metre of sail, so the researchers are examining different packing techniques.
"It's similar technology to a solar sail. The test will check that [sail] deployment works and confirm that our understanding is correct. We are thinking about 10kg [22lb] nanosatellite missions initially, but the technology could be used by any satellite in LEO in future," says Dr Stephen Hobbs, a senior lecturer contributing to the project at UK Cranfield University's Cranfield Space Research Centre.
Hobbs adds that the sail mass would be justified on the basis that it would replace the de-orbit motors now used. This would mean a benchmark sail mass of 5% of the spacecraft's total. For a 10kg nanosat this means the 10m2 sail (107ft2) has to be less than half a kilo, which Hobbs admits is another challenge for the researchers.
The sail's advantage over a motor, he argues, is that it is not attitude dependent, as a malfunctioning satellite's orientation may be unknown and the de-orbit engine could send it in any direction. As the sail would have to operate even when a satellite has completely failed, the reliability of its deployment system has to be high. This is also because of the danger that its early activation would de-orbit a satellite prematurely.
ROB COPPINGER / LONDON
Source: Flight International
