March 28, 2008 -- No one knows more about how complicated and time-consuming it is to assemble spacecraft in orbit than astronauts building the International Space Station.
After dropping off the first part of Japan's new lab and assembling a robot to help with maintenance, the shuttle Endeavour crew ran an experiment that might make things a whole lot easier -- and cheaper -- for future space construction. They inflated three flexible tubes housed inside a chamber in the shuttle cargo bay with pressurized nitrogen gas, then heated them. The tubes then cooled, forming rigid structures.
"It's a great experiment to test some structures that might have some good application for space station or lunar habitat development," said Shuttle Flight Director Mike Moses.
Funded by the Air Force, the experiment called RIGEX was designed to test how well ground models and computer simulations predict what happens to the inflated structures in weightlessness. Once rigid, the sample tubes aboard Endeavour were blasted with vibrations to test their structural integrity.
The experiment was returned to Earth aboard the shuttle on Wednesday. It will be removed from the cargo bay and returned to scientists for analysis.
The military is looking at inflatable structures as a way to cut launch costs, increase spacecraft size and reduce power demands. Last year, it awarded a $750,000 contract to California-based SpaceDev to develop deployable booms for satellites.
The technology has caught NASA's eye as well. In the 1990s, the space agency developed a prototype inflatable habitat called TransHab.
Originally designed for use on Mars, the system was revamped for use as a crew living quarters aboard the space station.
Budget cuts forced NASA to cancel the project in 2000, but the technology was transferred to private industry. Las Vegas-based Bigelow Aerospace is using the TransHab design for a proposed complex of stations and habitats in orbit for commercial use.
Two prototype inflatable spacecraft, the Genesis 1 and 2, are already in orbit.
Bigelow plans to launch its first human habitable spacecraft, the Sundancer, in about two years.
Related Links:
Irene Klotz's blog: Space Diary