But once we're there—or even while we're on the way—we need to be able to live.

That means the basics of survival, like radiation safety, breathable air, and drinkable water. It also means more mundane everyday living solutions, like clothing and washing. The space agency needs to build rockets capable of getting humans to Mars, but it also needs to figure out a sufficient supply of wet wipes for everyone.

Based on NASA's 2015 draft technology roadmaps, published this week, downtime on a future far-flung mission might look something like this:

You take a shower in an enclosed system for "full-body cleansing" with all of the water collected for re-use, and pull on your lightweight, antimicrobial clothes that you've probably been wearing for most of the mission after "freshening" them with the closest thing to laundry you've got.