Researchers create small satellite that captures space debris semi-autonomously with nets
Scientists from the American, privately funded research university Rensselaer Polytechnic Institute are developing a relatively autonomously operating cubesat that is intended to capture space debris by shooting nets.
Named Oscar, the satellite is being developed by Professor Kurt Anderson and his students as a small, inexpensive satellite that picks pieces of space debris from the vacuum largely autonomously. The top of the satellite consists of four ‘gun barrels’ from which nets are shot that are attached to Oscar by wires. Small pieces of space debris are captured and dragged along with it. Up to four pieces of space debris can be captured, after which the satellite automatically exits its orbit and burns up in the atmosphere along with the space debris.
Oscar consists of three cubesats stacked on top of each other, with a total length of 30cm, a width of 10cm and a height of also 10cm. One of these units houses the brain of the satellite, including a GPS sensor, data storage, communication equipment and the electricity supply. A second unit houses fuel and the propulsion module. The third and top unit contains the four barrels, the nets and the wires. According to Anderson, this firing and trapping mechanism has been designed before and is a fairly simple part of Oscar. The tricky part is integrating and optimizing the brain.
The device is designed to operate semi-autonomously. This autonomous character is difficult to realize, according to Anderson, because Oscar has to perform a task that is normally done by large, expensive satellites. Oscar uses the existing mapped collection of 22,300 pieces of space debris. The satellite must locate pieces of space debris using this database and data from the optical, heat and radar sensors. In this way, the satellite can largely independently chase space debris without requiring much control from the ground.
The development team envisions a future where hordes of Oscar satellites will be sent into clouds of space debris, with the cubesats also routinely being carried on large spaceships. Oscar’s algorithms are currently being perfected. The makers hope to do a test on the ground this year, followed by a test in space.
According to Anderson, the need for such a debris clearer is great. “The number of observed pieces of space debris is increasing faster than the rate at which we actually place objects in space. This is an indication that Kessler syndrome may be on the way.” With this, Anderson is referring to a theory by NASA scientist Donald Kessler. In 1978 he sketched a scenario in which low Earth orbit becomes so crowded that collisions will lead to a domino effect.