How do you service a satellite?
Though the vast majority of satellites were not designed to be serviced, NASA is looking into ways to make it possible to extend their operational lives. Similar to how a car can be repaired and receive more fuel, satellite servicing seeks to make the same options available to satellites. Most satellites use fuel to maintain orbit control, so the depletion of fuel can end a satellite’s life. In addition, parts wear out and components fail or become obsolete, which can also prematurely end or limit a satellite’s usefulness. Servicing can entail orbit relocation, or can be more ambitious with the addition of robotic replacement of components or the transfer of fuel in space.
Satellite servicing efforts have been limited thus far due to cost. Astronauts famously repaired the Hubble Space Telescope with a series of Space Shuttle missions from 1993 to 2009. Satellite servicing is becoming more economically viable with the decrease in launch costs and the advancement of technology. The use of common interfaces or cooperative servicing aids in future satellite designs will make servicing more common.
In order to service a satellite, a servicer must meet up with the satellite while flying thousands of miles per hour. A servicer needs to manoeuvre and perform autonomous rendezvous and proximity operations using cameras, machine-vision systems and high-speed avionics. Once the servicer mates with the satellite, dexterous robots and specialised tools can be used to transfer fuel to the satellite.
The first-ever refuelling of a satellite not designed to be serviced will be demonstrated by NASA’s On-orbit Servicing, Assembly and Manufacturing 1 (OSAM-1) mission.
“a servicer must meet up with the satellite while flying thousands of miles per hour”
Brent Robertson