Aerodynamic End Of Life Deorbit System
Engineers at the University of Glasgow and Clyde Space Ltd have developed a practical approach to the increasing problem of space debris in connection with the smaller low earth orbit CubeSats. Millions of pieces of ‘space junk' are orbiting the Earth as a side-effect of human exploration and exploitation of space. Pieces ranging from fragments of bigger objects, such as rocket boosters, to full-sized pieces of defunct equipment, and working satellites and spacecraft can be damaged by debris collisions. The University's School of Engineering Dr Patrick Harkness has led the project AEOLDOS (Aerodynamic End Of Life Deorbit System) to help ensure future objects sent into space can be removed from orbit at the end of their operational cycle. AEOLDOS is lightweight, foldable ‘aerobrake' which can be added to the small CubeSats before being launched. Once the satellite reaches the end of its operational life, the aerobrake, made from a thin membrane, supported by tape-measure-like struts, opens to generate aerodynamic drag against the extremely thin upper atmosphere that exists in near-Earth space. As the satellite falls out of orbit, the aerodynamic effects increase, causing it to harmlessly burn up during its descent. Glasgow-based SME Clyde Space, which builds small and micro spacecraft systems, is working with Dr Harkness to apply AEOLDOS technology to the CubeSats it provides to customers worldwide. CubeSats are used for space-related research projects and generally sent into space as secondary payloads on larger launch vehicles. "It's only been 55 years since Sputnik, the first man-made satellite, was sent into orbit, but since then we've managed to make made quite a mess of the space around our planet. The rate at which we're putting objects into orbit is accelerating each year, which is why it's vital for us to take more control over how they can be removed from orbit once they have served their purpose," said Dr Harkness. "CubeSats are currently aimed at lower orbits than is necessarily desired, to ensure they will re-enter the Earth's atmosphere within 25 years in order to meet official recommendations set by the United Nations Office for Outer Space Affairs. This can curtail and impact the full scientific potential of CubeSats. But AEOLDOS gives users much more control over the end of their project's life, and could enable missions to take place at much higher altitudes as they know we can always produce the drag they will need to dispose of the spacecraft in time." The tape measure deployment system has been developed by Malcolm McRobb, also from the School of Engineering. Coiling the tapes stores the energy within them, which can be released years later to deploy the membrane. McRobb believes AEOLDOS has applications beyond space debris control. "The technology could be used to enable solar sailing missions, where spacecraft can manoeuvre using the pressure of sunlight. It could form the basis of deployable antennae, increasing the sensitivity of small, low-powered spacecraft," he explains. "We expect that another year to 18 months of development will see the AEOLDOS system available for commercial use, through our licensing agreement with Clyde Space. After we have demonstrated that the technology can work in space, we are looking forward to designing tnew and exciting applications for the device."
PDF
