Image: NASA Marshall Space Flight Center

It's hard to say what this giant, ultralight, inflatable ring might become. But engineers at the NASA Marshall Space Flight Center, like Bob Engberg (left, in photograph) and John Lassiter(right), hope that with further refinement it will find a number of useful applications. They envision aids for high-tech space travel ranging from communications antennas and solar energy collectors to concentrators for sun-powered rocket engines and orbiting telescope mirrors. Marshall engineers recently finished a round of investigations aimed at developing reliable methods of testing such ultralight structures.

In fact, this ring is the sixth such prototype to undergo scrutiny at Marshall and is now headed to NASA's Langley Research Center for additional probing. It is, indeed, remarkably light for its size: the 21-foot gold inflatable ring and 16.4-foot silver reflector inside together weigh less than eight pounds. The superlight plastic membrane is one third as thick as a piece of paper. Because thin-walled membranes such as this one weigh so little, they are thought to hold promise as building materials in space. Also, because they can be deflated, they could be much less expensive to launch than traditional metal and composite structures.