The Bigelow Space Hotel

A remarkable technology that envisions building inflatable modules, developed by NASA and once envisioned for the International Space Station, could prove to be a key to opening up the high frontier of space for commercial development. If this becomes the case, it could prove to be the ultimate example of a “spin-off”, in which something made for the space program benefits the private sector.

The concept, developed in 1997 at NASA’s Johnson Space Flight Center, was called “transhab.” Transhab was envisioned as replacing the more conventional habitation module planned for the International Space Station. Eventually it would have been the basis of inflatable modules for lunar and Mars expeditions.

Transhab would have consisted of two dozen layers of material that was designed to protect equipment and people inside it from micrometeor impacts, radiation, and the heat and cold of outer space. The key to the debris protection would have been successive layers of Nextel, a material commonly used as insulation under the hoods of many cars, spaced between several-inches-thick layers of open cell foam, similar to foam used for chair cushions on Earth. The Nextel and foam layers would have caused a particle to shatter as it hits, losing more and more of its energy as it penetrates deeper.

Many layers into the shell would have been a layer of superstrong woven Kevlar that would have held the module’s shape. The air would been have held inside by three bladders of Combitherm, a material commonly used in the food-packing industry. The innermost layer, forming the inside wall of the module, would have been Nomex cloth, a fireproof material that also protects the bladder from scuffs and scratches.