Inflatables? Space Exploration is Just the Place for Them

Lots of big news about an inflatable addition to the international space state as in Air & Space's The Future of Construction in Space:
Is the International Space Station the last aluminum spacecraft?

Late this year or early next, NASA will build an addition to the International Space Station, increasing the orbital laboratory’s size from eight rooms to nine. The new room is like no other on the station, and will be very easy to construct: Just connect to a docking port, fill with compressed air, and voilà! Instant space habitat.

The hard part was the 15 years of re­search and development that Bigelow Aerospace in North Las Vegas needed to create the Bigelow Expandable Activity Module, or BEAM. Initially scheduled for a September launch, BEAM’s test deployment is now delayed due to the post-launch explosion of a SpaceX Falcon 9 rocket bound for the ISS on June 28 — and no one yet knows how long that delay will be. Once BEAM does reach its destination, it will undergo two years of intensive testing, a trial run for a technology that could play a significant role in future human spaceflight and low-Earth-orbit commercial ventures: inflatable spacecraft.

Yes, I noted this Bigelow module last year here and the concept is very interesting.

On the other hand, as set out in my prior post, Raymond Z. Gallun was pushing such an idea back in 1961.

Seems I read something about this concept in The Planet Strappers by Raymond Z. Gallun:

Nelsen didn't listen anymore. His and Paul's attention had wandered to the largest color photo thumbtacked to the wall, above the TV set, and the shelf of dog-eared technical books. It showed a fragile, pearly ring, almost diaphanous, hanging tilted against spatial blackness and pinpoint stars. Its hub was a cylindrical spindle, with radial guys of fine, stainless steel wire. It was like the earliest ideas about a space station, yet it was also different. To many—Frank Nelsen and Paul Hendricks certainly included—such devices had as much beauty as a yacht under full sail had ever had for anybody.

Old Paul smirked with pleasure. "It's a shame, ain't it, Frank—calling a pretty thing like that a 'bubb'—it's an ugly word. Or even a 'space bubble.' Technical talk gets kind of cheap."

"I don't mind," Frank Nelsen answered. "Our first one, here, could look just as nice—inflated, and riding free against the stars."

He touched the crinkly material, draped across its wooden support.

"It will," the old man promised. "Funny—not so long ago people thought that space ships would have to be really rigid—all metal. So how did they turn out? Made of stellene, mostly—an improved form of polyethylene—almost the same stuff as a weather balloon."

"A few millimeters thick, light, perfectly flexible when deflated," Nelsen added. "Cut out and cement your bubb together in any shape you choose. Fold it up firmly, like a parachute—it makes a small package that can be carried up into orbit in a blastoff rocket with the best efficiency. There, attached flasks of breathable atmosphere fill it out in a minute. Eight pounds pressure makes it fairly solid in a vacuum. So, behold—you've got breathing and living room, inside. There's nylon cording for increased strength—as in an automobile tire—though not nearly as much. There's a silicone gum between the thin double layers, to seal possible meteor punctures. A darkening lead-salt impregnation in the otherwise transparent stellene cuts radiation entry below the danger level, and filters the glare and the hard ultra-violet out of the sunshine. So there you are, all set up."

"Rig your hub and guy wires," old Paul carried on, cheerfully. "Attach your sun-powered ionic drive, set up your air-restorer, spin your vehicle for centrifuge-gravity, and you're ready to move—out of orbit."

They laughed, because getting into space wasn't as easy as they made it sound. The bubbs, one of the basic inventions that made interplanetary travel possible, were, for all their almost vagabondish simplicity, still a concession in lightness and compactness for atmospheric transit, to that first and greatest problem—breaking the terrific initial grip of Earth's gravity from the ground upward, and gaining stable orbital speed. Only a tremendously costly rocket, with a thrust greater than its own weight when fully loaded, could do that. Buying a blastoff passage had to be expensive.

Of course, Gallun wrote in 1961, so we all know that his idea of a space craft made of cheap materials and dependent on recycled air (or air produced by plants grown on board) was . . . ahead of its time?

Some artistic renderings of "planet strapper" craft, in addition to those on the book cover, here.