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More details emerge on NASA's plan for inflatable ISS module

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January 20, 2013

The Bigelow BEAM installed onto the ISS (Photo: NASA/Bigelow)

The Bigelow BEAM installed onto the ISS (Photo: NASA/Bigelow)

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NASA announced last week that it has contracted Bigelow Aerospace to construct an inflatable module to test on the International Space Station. Following the release of more information and imagery, here's a closer look at what the plan entails.

The Bigelow Expandable Activity Module (BEAM) is an expandable space station module currently being developed by Bigelow Aerospace, under contract to NASA, for use as a module on the International Space Station (ISS) during 2015 to 2017.

Bigelow Aerospace licensed the technology developed by NASA for multi-layer expandable space modules after Congress cancelled the SpaceHab unit being developed as part of the International Space Station (ISS) in 1999. Bigelow has now spent a decade and nearly US$200 million on the technology and practice of inflatable space habitats, including launching two test modules, Genesis I and II, into orbit in the mid-2000s.

Full size mockup of the Bigelow Expandable Activity Module to be added to the ISS (Photo: ...
Full size mockup of the Bigelow Expandable Activity Module to be added to the ISS (Photo: NASA)

The BEAM module being developed for the ISS is quite small, and will only add about two percent to the overall pressurized volume of the ISS. Four meters (13 ft) in length and 3.2 m (10.5 ft.) in diameter, the BEAM is roughly cylindrical in shape. (A doughnut-shape was considered initially, but in the end a cylinder seemed more likely to meet NASA's testing requirements.)

The BEAM module will be launched in folded form in the unpressurized cargo compartment on the eighth SpaceX Dragon cargo resupply mission, currently scheduled for 2015. Following on-orbit arrival at the ISS, a robotic arm will be used to install the BEAM on the aft port of the Tranquility node (see NASA video below). Afterwards, the station crew will activate a pressurization system to expand the structure to its full size using air stored within the packed module.

The fabric walls consist of several sets of layers. On the outside there is a layer made up of sheets of aluminum foil separated from one another by a small space. This serves two functions. The separation makes the outer layer act as an extremely efficient and lightweight thermal insulation, similar in concept to that being constructed for the James Webb Space Telescope. The second function is that of a Whipple shield, which serves to vaporize the smallest micrometeoroids, thereby allowing inner layers to avoid penetration.

Next is a set of several layers of more substantial Whipple shields. These consist of a thin metal sheet positioned over and separated from a thicker sheet. They work the same as the thermal insulation layer, but protect the contents of the BEAM module from larger micrometeoroids.

The inner layers of the walls comprise several sheets of Vectran, a super-strength polymer having about double the strength of Kevlar. These protect against both external and internal penetration, and are strong enough to survive, say, pieces of equipment accidentally propelled into the inner walls. Despite their intricate structure, the walls weigh only about 25 kg/sq m (5.5 lb/sq ft), compared to about 110 kg/sq m (25 lb/sq ft) for a similar sized ISS compartment built using conventional construction.

Testing indicates that the BEAM walls will be at least as resistant to both radiation and micrometeoroids as is the rest of the ISS. An advantage of the inflatable modules for deep-space applications is that, unlike metal, high-energy cosmic rays just pass through without forming a shower of secondary high energy x-rays.

The International Space Station (Photo: NASA)
The International Space Station (Photo: NASA)

During the two-year test period, station crew members and ground-based engineers will gather performance data on the module, including its structural integrity and leak rate. An assortment of instruments embedded within module also will provide important insights on its response to the space environment. This includes radiation and temperature changes compared with traditional aluminum modules.

Astronauts will occasionally enter the module to gather performance data and perform inspections. “The plan is to have the hatch closed most of the time, with the crew going in and out a few times a year to collect data," says NASA Deputy Administrator Lori Garver.

Following the test period, the module will be jettisoned from the station, burning up on re-entry.

Bigelow also plans to build a second BEAM module for use as an airlock on its Bigelow Commercial Space Station. The module's inflatable nature would provide room for up to three crew or tourists to spacewalk simultaneously, compared with a maximum of two that can operate outside the ISS.

Source: NASA

About the Author
Brian Dodson From an early age Brian wanted to become a scientist. He did, earning a Ph.D. in physics and embarking on an R&D career which has recently broken the 40th anniversary. What he didn't expect was that along the way he would become a patent agent, a rocket scientist, a gourmet cook, a biotech entrepreneur, an opera tenor and a science writer.   All articles by Brian Dodson
6 Comments

At first this announcement seemed quite exciting, but after further reading of the details, it seems it is just a small experimental space tent which may or may not lead to bigger and better versions in the future.

I suppose they are currently limited by rocket payload sizes though, which will change in the future, hopefully.

One of the good aspects about this experiment, is that NASA technology and projects that were never allowed to be completed (usually due to budget or politics) are being handed on to private American space companies that are now being allowed to make use of them.

Oztechi
20th January, 2013 @ 05:29 pm PST

Excellent approach to carefully test it over a number of years.

Too bad our GMO food supply does not warrant such care.

Pres
20th January, 2013 @ 09:34 pm PST

it has the dimension of a space-toilet

Gaetano Marano
21st January, 2013 @ 08:48 am PST

It's a probability game.

Factoring Murphy's Law means it'll pass the two year test, then kill a dozen balloonauts five years down the road with a larger, or more energetic, micrometeorite.

This is corporate welfare at its finest, IMO.

solutions4circuits
21st January, 2013 @ 12:25 pm PST

They should put a layer of self-sealant between some of the layers so in case of puncture it closes back up before losing too much air.

Cecil Hutchins
21st January, 2013 @ 02:06 pm PST

Shades of "Back to the Future" in the sense that what is new isn't really new. I am glad to see that such an experiment will be performed to live test the concept. I remember seeing this concept in the 50s on the Walt Disney program. Their presentation was to build a ring type space station, you would inflate the donut first then attach the pre-formed metal outer walls to the inflated portion to eventually build a hard environment.

It seems a shame that they will destroy it when done like the Skylab. I really don't understand the waste. That is the true corporate welfare not the possiblilty of catastrophe in the future. When one enters a hostile environment whether the depths of our oceans or the vastness of space, people will die. The gain is worth the cost. The survival of our species justifies all the risk and cost.

History Nut
21st January, 2013 @ 02:55 pm PST
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