Sierra Space recently completed a crucial test on its inflatable space habitat, bringing the company one step closer to launching and operating a private space station in partnership with Blue Origin within the next decade.
The test, known as the “ultimate burst pressure” test, was conducted at NASA’s Marshall Space Flight Center. As the name suggests, the purpose of the test was to inflate the module until it reaches its breaking point. Engineers were able to pump the module up to 77 psi before it burst, exceeding NASA’s recommended safety level of 60.8 psi by an impressive 27%.
This was not the first burst test conducted by Sierra on its Large Integrated Flexible Environment (LIFE) habitat, but it was the first on a full-scale module. Standing at over 20-feet-tall and one-third the volume of the International Space Station, the full-scale module is a significant achievement for the company.
Sierra systems engineer Leanne Thompson highlighted the significance of this accomplishment in a recent video, noting that it took NASA 10-15 launches to send up the same amount of habitable space to the ISS. Not only is the LIFE module more efficient, but it is also designed to fit inside a standard five-meter payload fairing. However, the company is already working on larger iterations of 1,400 cubic meters that could fit in a seven-meter fairing, making it larger than the ISS.
The focus of the burst test was on the LIFE habitat’s pressure shell or restraint layer, which is made of expandable “softgoods” that mimic the strength of a rigid structure once inflated. These softgoods have a long-standing history in aerospace, with inflatable airlocks and demonstration modules developed by Bigelow Aerospace in the 2000s.
The materials used in the LIFE habitat’s softgoods include Vectran straps, made from high-performance polymers. Sierra revealed in a press release that Vectran is even stronger than steel when inflated in orbit. The company is collaborating with ILC Dover to design and test these straps prior to the full-scale test.
Despite the significance of the burst test, it would be unwise to compare the LIFE module to a simple balloon. Sierra showcases the complexity of the module in a brief video, highlighting nine different layers that make up each module including thermal insulation and an outer cover.
Sierra’s ultimate goal is to deploy the LIFE modules in low Earth orbit as part of the Orbital Reef project, a private space station being developed in partnership with Blue Origin. Interestingly, the press release specifically mentions this project, possibly in response to reports from CNBC last year that suggested it was on the brink of falling apart.
According to Sierra, this year will be dedicated to aggressive testing at both sub and full-scale of the other layers of the LIFE habitat.