You would never buy a hundred million-dollar computer without a repair plan, but that's exactly what NASA does when it sends costly satellites into space. To ensure that its prized eyes-in-the-sky don't become the solar system's most expensive e-waste, the space agency is now building a robot capable of repairing and refuelling satellites in orbit.
Artist's concept of Restore-L. Image: NASA
NASA has just announced that it will award a $US127 million ($170 million) contract to the California-based satellite company Space Systems/Loral for Restore-L, a robotic spacecraft capable of grasping, refuelling and relocating a satellite in low Earth orbit, in addition to testing technologies for future missions. SSL has three years to build the bot, which is projected to launch in 2020.
An engineering design unit of NASA's Robotic Servicing Arm, which will be used on Restore-L. Image: NASA/Chris Gunn
Without the ability to refuel, a satellite's lifespan is restricted by the amount of propellant engineers can pack in its tank at launch. That lifespan can be cut even shorter should the spacecraft encounter any electrical or mechanical problems on orbit. As more and more satellites reach the end of their operational lifespans, government agencies and private companies have been working to remedy this problem by developing robots that can give satellites a tune-up in zero-gravity.
DARPA, for instance, recently launched a program aimed at designing robots capable of servicing satellites at the hard-to-reach but highly-desirable perch of geosynchronous orbit, 35,400km above Earth. NASA's Satellite Servicing Division, meanwhile, has a handful of on-orbit repair and refuelling technology demonstrators in the works, including a robotic arm with the same range of motion as a human arm, a navigation system designed to help robots rendezvous with moving objects in space and Restore-L, which combines these and other capabilities into a multi-purpose space mechanic.
For now, Restore-L's primary goal is to refuel Landsat 7, a critical Earth-monitoring satellite operated by NASA and the US Geological Survey. If successful, the spacecraft may be modified for all sorts of other useful tasks, from mopping up the ever-growing halo of space junk encircling our planet, to servicing exciting new science missions like the Asteroid Redirect Mission, which will grab a multi-tonne boulder from the surface of an asteroid and tow it back to orbit around the Moon.