PDF Basket
Since the launch of the first artificial satellite, Sputnik, in 1957, human activity in space has left behind debris from obsolete satellites and other waste materials. In addition to the large quantity of traceable man-made objects in Earth’s orbit, there are many millions of pieces of debris too small to be tracked in and around the planet – all of which are potential threats to spacecraft and satellites.
Our reliance on space technologies is set to increase further in the coming decades with mega-satellite constellations such as Oneweb and SpaceX Starlink being deployed. Keeping the quantity of space debris under control and ensuring the continued sustainable use of space has therefore become a pressing issue.
The EU-funded REMOVEDEBRIS project was the first low-cost mission to demonstrate, in orbit, a number of key technologies for active debris removal as part of the search for the best and most cost-effective ways of cleaning up space. The mission made a significant contribution to the state-of-the-art for future debris removal missions on a larger scale.
‘What is at stake is the continuation of the use of space,’ says project coordinator Guglielmo Aglietti, director of the Surrey Space Centre in the UK. ‘It is important that we start to think seriously about the sustainability of the space environment. There are guidelines for disposal of space satellites but they are not always respected, so we also really want to raise awareness of the consequences of this in the longer term and find workable and cost-effective solutions.’
Active intervention
REMOVEDEBRIS was developed by a consortium of companies and research organisations to design and build an experimental satellite that was deployed in June 2018. The spacecraft tested, in situ, three cost-effective key technologies for active debris removal. These included a net system to capture and trap debris, a harpoon to capture a specific target, and a drag sail to be deployed at the end of the mission to de-orbit the satellite. The mission was also supported by a Vision Based Navigation system to validate debris-tracking techniques in orbit with cameras and LIDAR.
Over the term of the project, the mission used two CubeSats as artificial debris targets, which were released from the main satellite then recaptured using the net and harpoon. The functioning of these devices was successful and carefully monitored throughout to provide input for further development and fine-tuning of the technology.
‘The opportunity to test the use of these technologies in a real operational space environment was invaluable as it allowed us to better understand the specific challenges involved and make improvements for the future,’ says Aglietti. ‘The drag sail element, for example, did not deploy exactly as planned. We learned from this experience, however, and this technology has since been commercialised and used successfully in two separate real-life missions.’
In addition to its technical achievements, REMOVEDEBRIS attracted significant media attention, which has helped to raise public awareness of this issue. ‘This is really important as many of these space missions can only happen if there is public support and pressure on government and funding agencies to support them,’ Aglietti adds. ‘Hopefully this will help to create momentum towards the delivery of more missions to remove some of the large debris currently orbiting around the Earth.’