Britain wants to keep space tidy, so the UK Space Agency (UKSA) has awarded a £61-million (US$81-million) contract to remove two defunct UK satellites from orbit between 2029 and 2032 using manipulator spacecraft launched from the Shetlands.
According to ESA, there are between 35,000 and 50,000 pieces of debris orbiting the Earth with a diameter of over 10 cm (4 in), including up to 3,500 defunct satellites. This may seem like a lot, but, as The Hitchhiker's Guide to the Galaxy says, space is big. Really big. When you consider how much of it there is between the Earth and even halfway to the Moon, this flotsam is minuscule in comparison.
However, most of this debris moves in a series of narrow orbital bands – much as ocean traffic is confined to a few sea lanes. In addition, since all this debris is moving at orbital velocity, a fleck of paint traveling in the opposite direction to an operational satellite can hit it at a speed in excess of Mach 47.
The result can be extremely nasty. Worse, it can produce a cascade effect where a collision creates more debris and then more debris for more collisions until large areas of Earth orbit can become an effective no-go zone.
This may sound very depressing and chaotic, but, in recent years, there has been some progress in reducing this hazard. Systems have been set up to track, catalog, and give warning of any dangerous debris. Along with this, spacecraft are now required to be built to avoid shedding debris or including unstable components like potentially explosive batteries or propulsion systems.
On top of all this, satellites are subject to precedents set by maritime law and are the responsibility of the nations whose flag they fly under. Long story short, nations have to get rid of their inactive spacecraft or pay for any damage they cause.
It's in light of this responsibility that the UKSA has contracted ClearSpace UK to help design, build, and test two special spacecraft that can also be used for future In-orbit Servicing, Assembly, and Manufacturing (ISAM) commercial missions.
The purpose of the craft will be to dispose of two still undisclosed British satellites in low-Earth orbit that have gone non-operational and no longer respond to commands. Launched from SaxaVord Spaceport in the Shetland Islands north of Scotland, the spacecraft will rendezvous with the dead satellites under autonomous Guidance, Navigation, and Control (GNC). It will then use computer vision and robotic manipulators to grapple with the target and then use its thrusters to push the satellite into a controlled reentry orbit, during which it will burn up in the Earth's atmosphere.
The mission is still unnamed, but UKSA is running a competition if you want to give it a moniker. I'm submitting "Spacey McSpaceface."
"Space junk and debris pose an immense and growing challenge, but with our homegrown expertise, the UK is determined to lead the global effort to clean up space," said Space Minister Liz Lloyd. "By backing this world-first mission, we will protect the satellites that underpin modern life, from keeping us connected with loved ones and delivering accurate weather forecasts to keeping our country safe."
Source: ClearSpace
