Okay, not balloons, exactly, but the next closest thing: inflatable habitation modules.
With existing technology, the planned travel time to Mars is about six months. That’s a lot of time cooped up in a small spacecraft. Even steely-eyed astronauts will go buggy being kept in a confined space with the same people for so long. Using larger crew modules significantly helps, but that means more mass, which means more fuel, which means less other stuff to use once the mission gets to Mars. NASA needs a way to get more for less.
Bigelow Aerospace is one company betting on what is called expandable module technology to provide just that: more usable space for less mass and launch space. Essentially it’s an inflatable balloon used to house people. Currently, NASA has contracted with Bigelow to launch a ‘Bigelow Expanded Activity Module’ – or BEAM – inside an unpressurized SpaceX Dragon capsule to dock with the International Space Station (ISS). It will launch in early 2016. Once coupled with the station, it will be inflated and used as a two-year test for expandable technology. It will see very limited use. According to NASA, its hatch will be closed most of the time, and it will only be accessed to take readings on such things as leak tests, radiation, etc. When its time is up, it will be jettisoned and sent into the atmosphere to burn up.
The original idea was to use the test to assess expandable technology for use on the first mission to Mars. Bigelow has designed a contender for this mission: the B330 module. With a usable volume of 330 square meters (hence the name), it is more than three times larger than the Destiny module on the ISS, but weighs in at only 33% more mass. It also has similar radiation and impact protection to Destiny. The 330 may end up getting a boost, thanks to Congress.
Unlike most of the time, Congress is actually helping the space program. A recent omnibus spending bill has allocated $55M to figure out exactly what a Mars habitation module will look like. The issue is that the bill dictates that a prototype must be developed by mid-2018 – well before the BEAM mission is over and the data studied. The big question is whether this will help or hurt Bigelow and its inflatable designs. On one hand, Bigelow already has its 330 design, so presumably it has a leg up. On the other, NASA is notoriously cautious and may end up discounting such designs without a full study in place, opting instead to build a prototype using more traditional configurations because the BEAM mission won’t be complete.
Will astronauts be traveling to Mars in inflatable spacecraft? It’s currently unknown, but the technology does stand a good chance and represents a number of advantages over rigid designs. Regardless, space travel got a nice boost with Congress’ rare action and support of the space program.