NASA has chosen Elon Musk’s SpaceX to take over the International Space Station at the end of its life.
The California-based company will develop a vehicle capable of pushing a 430-ton orbital platform into the Pacific Ocean over the next decade.
The contract for the work, worth $843m (£668m), was announced on Wednesday.
The first components of the space station were launched in 1998, with continued crew operations beginning in 2000.
The station orbits the Earth at an altitude of 400 km (250 mi) every 90 minutes and has been home to thousands of scientific experiments, investigating everything from the aging process in humans to the formulation of new types of materials.
Engineers say the lab is structurally sound, but plans to dismantle it need to be put in place now. Without help, it will eventually return to Earth, although this poses a significant risk to people on the ground.
“The selection of a US de-orbit vehicle for the International Space Station (ISS) will help NASA and its international partners ensure a safe and responsible transition to low Earth orbit at the end of station operations. This decision supports NASA’s plans for future commercial missions and allows continued use of near-Earth space.” Ken Bowersachs, the agency’s director of space operations, said in a statement.
The ISS program is led by the US and Russia. Europe, Canada and Japan play supporting roles. All Western partners have agreed to fund the station by 2030; Russia says its involvement will last until at least 2028.
This includes decommissioning the station and using younger components on the next-generation platform. Another idea is to entrust it to some business concern to operate and maintain it.
But all of these solutions have various issues of complexity and cost, as well as legal issues that need to be unraveled over issues of ownership.
Neither NASA nor SpaceX have released details of the de-orbiting “duck boat” design, but it would require considerable propulsion to safely navigate the station into the atmosphere in the right place and at the right time.
Due to the large mass and size of the site – roughly the dimensions of a football pitch – some structures and components retain re-entrant heat and make it all the way to the surface.
Controllers will allow the ISS’s orbit to decay naturally for a period of time, and after removing the last crew, command the tugboat to execute a final de-orbit maneuver.
The unwanted spacecraft are headed for a remote location in the Pacific known as Point Nemo.
Named after the famous submarine sailor in Jules Verne’s book 20,000 Leagues Under the Sea, the target cemetery is 2,500 km from the nearest land.
NASA hopes that several private consortiums will launch commercial space stations by the time the ISS is out of space.
The space agencies’ focus will shift to a project to build a gateway to orbit the moon.