Inflatable Space Modules Are Older Than You Think

Just a couple of days ago, the first inflatable space station module was attached and successfully inflated on the International Space Station. It's called the Bigelow Expandable Activity Module (BEAM), which sounds a little like the place where astronauts will play kickball, but it's really a bold experiment about the future of space habitats. Surprisingly, it's not the first inflatable module to go into space or even house a human.

The basic concept behind inflatable space habitats is a great idea, and goes back to the 1960s. The thinking is that in zero-gravity space, the walls of your habitats don't actually need to be load-bearing. You really just need to be able to enclose a volume of atmosphere and control the climate inside that volume. Since space is limited on launch vehicles, a habitat that launches to space compressed, and then expands to a much larger living and working volume would be ideal.

The Bigelow company has been working hard since 1999 to develop these sorts of modules, and it's only now, 17 years later, that they've finally managed to get one into orbit. Really, though, the BEAM module is the second inflatable space module to make it to orbit: the first one went up, and was actually used, back in 1965.

That first inflatable module was part of the Soviet Union's Voskhod 2 spacecraft, where it played the role of an airlock module for history's first spacewalk by cosmonaut Alexi Leonov.

Leonov's space-strolling achievement has largely overshadowed the technical details of how it was done, and a key component of how it happened was the inflatable module used as an airlock.

The reason the Soviets decided to use an inflatable module for an airlock was mostly to save time and money. The Voskhod spacecraft were essentially slightly modified Vostok spacecraft – the first vehicles to take a person into orbit – that were modified, initially, to carry more than one crew member.

When America announced the two-person Gemini capsules to take multi-person crews into orbit, the Soviets beat us to the punch by cramming three people into the Voskhod's (essentially the same as the earlier Vostok's) spherical re-entry sphere. To do so, those three cosmonauts had to give up space suits, which gave the Soviets another first, anyway.

The Gemini also had a pair of doors that allowed for astronaut egress in space for spacewalks; to get the same ability in the Voskhod, a more complex approach was needed. Where the Gemini would just vent out all its air and then repressurize when the doors were shut again, the Voskhod couldn't do that.

The reason was that the Voskhod used electronics based on vacuum tubes, which, like a Zaporozets, were air-cooled. Venting out all the air would have fried everything. So, an airlock was needed, which is what led to the development of the Volga airlock module, the first inflatable module to be used in space.

The airlock was really quite clever; all folded up, it was only about two feet thick, a little round burger slapped on the side of the Voskhod's re-entry sphere. When expanded, it provided 88 cubic feet of space, just enough for Alexi Leonov in his space suit to fit in.

So, really, decades and decades before the BEAM module currently ballooned up there on the ISS, there was a human-habitated (at least for a little while) inflatable orbital module whirling around the globe.

Aside from that first inflatable module in space, the Voskhod 2 mission was an amazing mix of triumphs and near disasters. Sure, Leonov managed to perform humanity's first spacewalk, but that wasn't enough to impress his own dad. According to Leonov himself, writing in Two Sides of the Moon: Our Story of the Cold War in Space, here's how Leonov's dad responded to the video of him walking in space:

"Why is he acting like a juvenile delinquent? Everyone else can complete their mission properly, inside the spacecraft. What is he doing clambering about outside? Somebody must tell him to get back inside immediately. He must be punished for this."

Holy shit. Poor Alexei.

Alexi's dickhead dad did sort of get his wish for punishment, because Leonov's space suit became so stiff from the air pressure inside that Leonov couldn't move his arms or legs enough to get back into the airlock. He was forced to, terrifyingly, vent air from his suit, and struggle to get back in the airlock and get the hatch closed. It was so difficult he almost suffered heat stroke and was 'sloshing' in his own sweat.

That wasn't all. The system to help the crew target their re-entry point failed, meaning they had to wait an extra orbit and fire the retro-rockets (the backup ones, because of course the primary ones failed) manually, which set them down in the middle of a snowstorm in Siberian woods, where they spent two frozen nights keeping bears and wolves at bay with a gun before they were finally rescued.

Oh, and I forgot, on the way back down to earth, a communication cable tethered the re-entry module to the service module, causing the whole assembly to spin wildly, subjecting the crew to an insane 10Gs of force.

Happy now, dad?So, this new BEAM module is an exciting step in the development of roomier modules for us when we venture into space. But let's take a moment to pay our respects to that very first attempt at living in space balloons, and also take a moment to thank space-god that our dads probably aren't as big of an asshole as Alexi Leonov's.