What happens to the International Space Station after 2020?

As pointed out by Rebecca Boyle over at PopSci, the NASA budget that the President will sign into law today extends the mission of the ISS until 2020, but leaves its further future in question. At that point, its lifespan will have been extended well beyond expectations, and it will have lived a good life, as far as such things go.

But even so, the thought of abandoning the ISS as a piece of elaborate space junk or sentencing it to atmospheric disintegration feels like a waste. And I'm not just being sentimental here--evidently, letters are circulating between the participating space agencies with fresh ideas for the aging orbiter. The standout plan would not only keep the ISS in action not just as an orbiting laboratory, but as a stepping stone for future manned flights.

The ISS-as-a-spaceport plan hinges on a small manned probe, sent to orbit around the Moon, after which it would return to earth. The ESA's director of human spaceflight, Simonetta Di Pippo, told the BBC:

The idea is to ascend to the space station the various elements of the mission, and then try to assemble the spacecraft at the ISS, and go from the orbit of the space station to the Moon

You'd be forgiven for thinking this plan, which doesn't even include a lunar landing, lacks ambition. But it would figure into a much broader plan for manned exploration further into the solar system. The supplies and type of craft necessary for months-long missions present problems for a traditional Earth launch, in which tremendous amounts of fuel are expended just to escape the Earth's gravity.

Beginning a mission from low orbit would eliminate a whole range of problems facing long-term manned spaceflight. But aside from the ISS itself, space agencies have had few opportunities to test the logistics of building in space, and even fewer to test the waters for an orbital launch. Building a ship in space, for obvious reasons, isn't quite the same and building one in a hangar in Texas.

Sending an Apollo-8-style capsule around the Moon might not sound like much, but it'd be a harbinger of much more exciting things to come.

The culmination of this vision, which would admittedly come decades from now, envisions the ISS, or similar structures, as a sort of base camp for missions to destinations as close as the Moon and as far as Mars, and to plenty of larger asteroids in between.

So when will we find out if the ISS will get its second (third? fourth?) chance? Not for a while. This plan is currently little more than high-level spitballing, and wouldn't have an opportunity to kick off for nearly a decade. But it bears a comforting implication: That agency bigwigs, not just romanticizing space nuts, would hate to see the ISS go to waste.

This post was originally published on Smartplanet.com