We already know that there’s a whole lot of junk at the top of the gravity well; a lot of it is dead satellites, and as much as we could blast the things apart, it’d probably be a lot more economical to ensure they have a longer working life. Enter MacDonald Dettwiler and Associates, a Canadian outfit who propose building an orbital platform for refuelling and repairing ailing satellites:

MDA wants to fill that niche by launching a satellite refueling station that can track down and dock with satellites in the sky, filling them up with hydrazine and performing small repairs. Such a service could double, or even triple, the lives of satellites already flying, provided their on-board instruments are still working properly.

But such a refueling station isn’t the same as pulling up to the gas pump, or even refueling a jet in flight. Satellites are roaring through space at nearly 7,000 miles per hour, so a fueling station would have to first catch the satellite in motion, then somehow finagle the fueling port open with a robotic arm of some kind — if, that is, the door hasn’t been seared closed by years of exposure to space. It’s been done exactly twice before, but both times it happened under experimental conditions where the satellite and the refueling vehicle were both new and designed to be compatible.

Still, it’s not impossible and MDA thinks it could make $100 million a year servicing satellites which themselves are very expensive to replace.

Another potentially lucrative business model for commercial space companies, and a lot less adventurous than asteroid mining (though I suspect it may turn out to be more technically challenging in some respects). It also looks (to my layman’s eye, at least) more sensible than the previously-mooted idea of sending up wandering repairbots.

Probably too little too late for poor old Zombiesat, though.