Space Refueling

MDA space infrastructure services plans to build a "spacebased service vehicle" that serves as a filling station for older, but still viable, satellites that are running out of fuel - as well as provide repair and even towing services for satellites that need greater assistance.

It could save satellite operators tens of billions of dollars over the next decade.

The service would be available to satellites in what's called "near geosynchronous orbit" some 36,000 kilometres above the surface of the Earth. The satellites in this orbit help deliver television, GPS, communications, and weather images.

There are roughly 400 such satellites, each with a replacement cost of about $250 million. About half will fail in the next decade and half of those - about 100 satellites - would need only a fill-up in order to remain operational for at least a few more years.

Gravity from the Sun and the Moon pull at the satellites enough that they gradually shift into an elliptical, or oval-shaped path - unless they occasionally fire small thrusters that adjust them back into their proper positions.

MDA anticipates that its service craft will launch by 2015 and commence a demonstration run in which it will dock with an Intelsat satellite in the graveyard beyond the geo orbit, and refuel it.

MDA is looking for other partners to co-finance the venture. The U.S. military has expressed preliminary but enthusiastic interest - in particular because it presents an opportunity to have space debris, including dead satellites, moved safely away from functioning satellite orbits.

The service vessel will be remotely controlled by system operators on Earth.

Dan King, MDA's director of orbital robotics, said the servicing craft will remain in orbit, and when it is running out of fuel a simpler, less sophisticated spacecraft - "essentially like a flying fuel tank" - will be launched to rendezvous with it and fill it back up.