Briefing: Space Tugs

The first could be chugging its way through space in three years.

Q: Mission?

A: To extend the lives of telecommunications satellites.

Q: What’s threatening them?

A: A finite supply of on-board propellant, the lifeblood that keeps satellites in orbit. When it runs out, satellites are sent into disposal orbit and decommissioned, meeting a fiery end as they re-enter the earth’s atmosphere. Burning them up removes waste and frees space in orbit for other satellites. But it can be an unnecessarily expensive exercise.

Q: In what sense?

A: In many cases, the communications payload could continue to operate long past the decommissioning date – for perhaps another 10 years. Orbital Recovery, the British firm behind space tugs, estimates there are 73 satellites in space that are commercially and technically viable beyond their decommissioning deadline.

Q: Space tugs are go?

A: They will be if Orbital Recovery manages to conclude deals with several satellite operators to make the first mission commercially feasible.

Q: What would it involve?

A: The space tug, officially called the ConeXpress Orbital Life Extension Vehicle, being launched by the same platform used to carry satellites into space aboard an Ariane 5 rocket. Once in space, the tugboat would prepare to rendezvous with the satellite running low on fuel and dock with its apogee kick motor.

Q: Then the pump starts running?

A: In a highly technical way. The space tug would provide the satellite with the propulsion, navigation and guidance necessary to keep it in orbit beyond the normal lifespan (usually some 12 years).

Q: Saving?

A: Potentially millions. Telecommunications satellites typically cost (pounds) 140m each. Extending their working life would deliver major savings.