Oops! They’ve done it again. Sierra Space blew up their space habitat for the third time – intentionally — all in the name of testing.
The commercial space company conducted a new duration test called an Accelerated Systematic Creep Test for their LIFE Habitat (Large Integrated Flexible Environment), putting a 1/3 size scale model of the space module under a sustained amount of excess pressure until it failed. The habitat burst after more than 150 hours of constant pressure, exceeding NASA’s certification target of 100 hours.
Sierra Space says that the test proves astronauts could live and work in a full-size version of the inflatable habitat for up to 60 years in space.
The video below shows the impressive explosion:
This video shows the test/explosion of the 1/3rd-scale unit, and also includes time lapse footage of the full-scale habitat, which inflates to the size of a three-story apartment building in space. Credit: Sierra Space.Sierra Space says the development of their ‘softgoods’ inflatable habitat technology is a key step in facilitating extended human missions to low-Earth orbit, the Moon and Mars. Sierra Space is a a subsidiary of Sierra Nevada Corporation.
“LIFE Habitat represents the essential technology developments needed to one day enable humans to live and work in space,” said Sierra Space CEO Tom Vice. “Habitat units are a key element in Sierra Space’s platform in space, and this crucial milestone illustrates that our team has exceeded programmatic requirements that validate critical aspects of the LIFE Habitat design. These results will propel us in 2023 as we mature the technology via full-scale development and continue toward full NASA certification.”
Previously, the LIFE Habitats were put under a different kind of stress test called an Ultimate Burst Pressure (UBP). Two of those test were conducted in July and November of 2022, and scale models of the modules were pressurized with increasing loads until they burst. Engineers filled the modules with gaseous nitrogen to test how strong the inflatable high-strength softgoods materials are, with the goal of climbing past 182.4 PSI (pounds per square inch) which is NASA’s thresholds for certification for pressurized modules. The first test exceeded that mark, bursting at 192 PSI. The November test held pressure until 204 PSI, giving the team a lot to celebrate.
The new test was conducted at Marshall Space Flight Center, and NASA designed a disposable building in which the test was performed to protect the module from weather during the test . Thank goodness the structure was disposable, because the whole thing exploded.
Creep tests have been a standard model of testing for space hardware. In the Apollo days, creep tests were routinely conducted for pressure vessels and fuel tanks.
A Subscale Version of LIFE™ Habitat (Large Integrated Flexible Environment) before the creep test. Credit: Sierra Space.The full-size version inflates to a three-story commercial habitation and science platform that is 8.2 meters (27 feet) in diameter and 8.2 meters long, with 300 cubic meters of space, or about 1/3 of the pressurized volume on the International Space Station. LIFE can house a crew of 4-12.
The module’s softgoods are made of sewn and woven fabrics – primarily Vectran – that become rigid structures when pressurized. Sierra Space said the weave they use is stronger than steel and tough enough to withstand the required internal pressure. The softgoods outer layers are composed of a series of materials designed for orbital debris and thermal protection.
Sierra Space will conduct another creep test for a scale model within the next few months and they hope to conduct a full scale model in a burst pressure test sometime later in 2023.
