A new type of flexible module is going to be added to the International Space Station on a two-year trial to see if it will be suitable for human occupation. If proven successful, it could lower the cost of future space habitation and colonization.

In space, weight equals money — to the tune of $10,000 per kilo, depending on the the rocket.  It is much cheaper to send up a small package and inflate it in space than build it full-size on the ground.

Bigelow Aerospace, a private space exploration firm based in Las Vegas, has been building inflatable structures for space since 1999. That include two unmanned prototypes called Genesis 1 and II that were sent into orbit as proof-of-concept projects.

The idea is that an inflatable module can provide 210 per cent more volume, with only 33 per cent more weight, than some of the existing all-metal modules currently on the space station. 

The latest module — called BEAM (Bigelow Expandable Activity Module) — is a small test version of what the company hopes will become a complete inflatable space habitat, the BA330. Able to hold a crew of six, it could serve as a scientific laboratory, or an orbiting hotel for the ultimate high-adventure tourist. Variations on the structure could be used as low-cost habitats on the moon or Mars.

Improving an existing concept

Inflatable structures have been around since the early days of space exploration. In fact, the first American passive communication satellite, Echo 1, was a mylar balloon as tall as a 10 storey building.

NASA included a flexible module in the original design for the International Space Station, but it was cancelled for budget reasons. So Bigelow Aerospace took up the task and is under contract to NASA to prove the technology works.

Space-X Falcon 9 rocket

The SpaceX Falcon 9 rocket with a Dragon capsule attached to its top is lifted into the vertical position during a rollout demonstration test at Cape Canaveral Air Force Station in Florida. SpaceX will make its 5th attempt to land the first stage of the rocket on a barge on the ocean after blasting its cargo into space. (NASA/Jim Grossmann)

The biggest concern is the safety of astronauts in structures that are not made of metal. Images of fabric being torn to shreds by micro-meteorites or space debris are easy to imagine.

In fact, the company says its inflatable structures are safer than metal ones. This is the result of advanced materials that can absorb impacts, and a thicker outer layer that includes water, which is not only tough, but also provides protection against radiation.

The BEAM module will be carried to space on a Falcon Rocket, built by another private company, Space-X, which has been delivering supplies to the space station.

Astronauts will use Canadarm 2 to attach the module to one of the ports on the station, where it will then be expanded to full size. During this test flight, astronauts will spend some restricted time inside the module to monitor conditions, check for leakage, look for damage from micro-meteorites, and measure radiation levels.

Following the test, the module will be jettisoned to burn up in the atmosphere.

Domes and flexible structures have always been a part of science fiction portrayals of the future. But until now, much of the focus in real life has been on building bigger rockets to get us to space, and constructing a rigid and very expensive space station. Bringing these space bubbles to reality could finally make it cheaper to actually live there.