NASA Really Needs Inflatable Space Rooms To Work

From Popular Mechanics

Bigelow Aerospace's BEAM space station module became the first inflatable anything in orbit when it launched aboard SpaceX's CRS-8 cargo resupply mission on April 8. Tomorrow, April 16, it'll attach to the International Space Station and begin a two-year testing period to pave the way for future inflatables. Jason Crusan, NASA's director of the Advanced Exploration Systems Division, tells PM what it means for the future of manned spaceflight.

PM: Is this the future of space exploration-space balloons with a human filling?

JC: [That's] what we're trying to figure out with this demonstration of BEAM. The entire history of human spaceflight, of actual modules flown in space, has been rigid, metallic structures, and metallics have some limitations-the largest structure you can ever build is one that fits in the rocket carrying it. For some of our long-duration missions to Mars, we need a volume that's rather large. Only then can we have places for all of our stowage and actually have a little volume for people to live.

NASA experimented with inflatables from the 1960s and took a serious run at them with TransHab in the 1990s. So why has it taken this long to actually get one up into orbit?

TransHab was the most substantial effort. So, the national policy in 2000 was for us to actually stand down our efforts related to TransHab, and we went ahead and proceeded with our ISS developments all using known technology: rigid structures. When it came to an end, the technology from TransHab was licensed to Bigelow.

We didn't have a real need to do the next habitation thing until now, when we're actually trying to build habitation structures to send ourselves to Mars.

How did Bigelow develop the project so fast?

Two years for hardware development for a space module shocked a lot of people. That's a really rapid approach from us and from Bigelow.

In part, [it's because] the module is a structural module. There isn't a bunch of life support equipment in it. It's as simple of a test as you can do. So that simplicity did a lot for the expedited test cycle and development-and-build cycle. We can now perform a demonstration at a relatively low cost and get that expandable performance data for our own deep-space mission. At the same time, they get data related to their own commercial endeavors for low-Earth orbit.

Did you hit any snags in working with BEAM?

Surprisingly, we had very few challenges in the development of the structure, how they were certified, and all that. The real challenging area came with the complexity of mixing this new innovative kind of demonstration and our safety that we need to ensure with the ISS, because we've never flown an expandable structure. "How will it expand?" is one of our questions. Does it expand outward first? Radially first? We don't know. The way it expands then could have an impact on potentially interfering with something on the space station. [But] we always do analysis on everything that could ever occur.

What advantages do inflatables have over rigid construction?

First and foremost is volume, going back to that rocket-ferrying problem. Another is mass, how much a module weighs compared to a same-size metallic module. At small sizes, like on the BEAM, there's not a huge mass savings between it and a standard metallic module that's reasonably close in size. The real advantage comes when you get to the larger 150-, 200-, 300-cubic-meter volumes.

Another advantage is radiation shielding. Metallic structures have interaction effects between radiation particles and the metals. This causes secondary radiation events. If you think about a radiation particle coming in at a high energy, it hits the metallics and then splits into a bunch of lower-energy particles that are just as dangerous, but now there are a lot more of them. In theory, in soft goods you don't have that splintering effect.

There's also no active heating system in BEAM. Between the layers of impact-resistant hull fabric and impact-absorbing foam spacers, there's a layer of air that holds temperature within a very small window, which is our standard temperature on the station.

And then there's structural strength. If you look at metallics versus soft goods-and I'll just use Kevlar as an example-Kevlar is almost ten times stronger than aluminum or even titanium. And the Vectran they're using on BEAM is stronger than Kevlar.

Is anybody else working on inflatables for space?

In active production? No. Bigelow's unique in that they are making private investment towards a commercial space station. We (NASA) are working on fundamental R&D related to expandable structures, but we are not building any in-house habitation expandable.

Bigelow's next step is the much-larger inflatable module BA-330, and from there, self-powered BA-330s and lunar lander BA-330s, as well as an entirely inflatable commercial space station. When are we going to see them, and spacecraft like them?

NASA is well under way building the new SLS rocket and Orion for deep space. The next thing that we need to enable deep-space missions is the habitation. We have studies ongoing with not only Bigelow but Boeing, Lockheed Martin, and Orbital ATK on how to approach our habitation strategy for deep space. Our current contracts on deep-space strategy, which Bigelow's BEAM was a part of, will complete by August or September 2016. We're going to look at moving on to our phase-two efforts with habitation, which will get us to ground-unit development that culminate in engineering tests at about 2018. Then we will proceed to flight habitation tests somewhere after that.

As far as landed systems on the moon or Mars or asteroids, those come after Earth and our in-space habitation needs.