Space: the final frontier for masonry.

Sending a single kilogram of anything into space costs $110,000, according to NASA (although SpaceX can apparently do it for less). To trim down the total cost of sending things into space on its upcoming launch to Mars, the US space agency is looking for ways to use the Red Planet’s native resources in lieu of imports.

Yesterday (Oct. 7) the space agency announced an open call for suggestions on how to turn Mars’ rocks into things astronauts can use.

NASA’s “In-Situ Materials Challenge” offers a $10,000 prize (and two $2,500 runner-up prizes) for the proposal that finds a use for the regolith and basalt rocks that comprise the Martian surface.

The agency isn’t ruling out any possibilities: Proposals could be for ways to turn the stuff into building blocks, buildings themselves, thermal shields, bridges, storage facilities—anything that might be useful to astronauts. NASA also provided the chemical composition of the average space rock, suggesting that scientists might look into breaking the rocks down into their component parts.

This isn’t the first time NASA has crowdsourced proposals on how to better use what the astronauts will have around with them. The space agency recently awarded Clemson University $200,000 to figure out how to turn astronaut pee into an array of useful items, from plastic for 3D printing to vitamins.

Scientists, universities or regular people with bright ideas have until Dec. 3 to submit a proposal. NASA said it’ll announce its winners in late January. If anyone figures out how to build something really useful by then, perhaps Elon Musk’s vision of colonizing Mars will finally come true.