BIGELOW AEROSPACE IS SENDING UP AN EXPANSION PACK FOR THE ISS

The first astronauts on Mars probably won't live in a tin can like the International Space Station. Big, heavy structures are expensive to launch, and aren't great at protecting against the radiation they'd be pummeled with on Mars. Instead, the first Martians might live in something like a pop-up tent.

Bigelow Aerospace designs inflatable space habitats--lightweight modules that ride compacted in the trunk of a spacecraft, then expand to a much larger size in space. In a launch scheduled for April 8, the company is sending one of its modules up to the International Space Station for testing.