Inflation System A "Glorified Scuba Tank"
A successful NASA flight test
Monday demonstrated how a spacecraft returning to Earth can use an
inflatable heat shield to slow and protect itself as it enters the
atmosphere at hypersonic speeds.
The Inflatable Re-entry Vehicle Experiment, or IRVE, was
vacuum-packed into a 15-inch diameter payload "shroud" and launched
on a small sounding rocket from NASA's Wallops Flight Facility on
Wallops Island, Va., at 8:52 a.m. EDT. The 10-foot diameter heat
shield, made of several layers of silicone-coated industrial
fabric, inflated with nitrogen to a mushroom shape in space several
minutes after liftoff.
The Black Brant 9 rocket took approximately four minutes to lift
the experiment to an altitude of 131 miles. Less than a minute
later it was released from its cover and started inflating on
schedule at 124 miles up. The inflation of the shield took less
than 90 seconds.
"Our inflation system, which is essentially a glorified scuba
tank, worked flawlessly and so did the flexible aeroshell," said
Neil Cheatwood, IRVE principal investigator and chief scientist for
the Hypersonics Project at NASA's Langley Research Center in
Hampton, Va. "We're really excited today because this is the first
time anyone has successfully flown an inflatable reentry
vehicle."
According to the cameras and sensors on board, the heat shield
expanded to its full size and went into a high-speed free fall. The
key focus of the research came about six and a half minutes into
the flight, at an altitude of about 50 miles, when the aeroshell
re-entered Earth's atmosphere and experienced its peak heating and
pressure measurements for a period of about 30 seconds.
An on board telemetry system captured data from instruments
during the test and broadcast the information to engineers on the
ground in real time. The technology demonstrator splashed down and
sank in the Atlantic Ocean about 90 miles east of Virginia's
Wallops Island.
Photo Courtesy NASA
"This was a small-scale demonstrator," said Mary Beth Wusk, IRVE
project manager, based at Langley. "Now that we've proven the
concept, we'd like to build more advanced aeroshells capable of
handling higher heat rates."
Inflatable heat shields hold promise for future planetary
missions, according to researchers. To land more mass on Mars at
higher surface elevations, for instance, mission planners need to
maximize the drag area of the entry system. The larger the diameter
of the aeroshell, the bigger the payload can be.
The Inflatable Re-entry Vehicle Experiment is an example of how
NASA is using its aeronautics expertise to support the development
of future spacecraft. The Fundamental Aeronautics Program within
NASA's Aeronautics Research Mission Directorate in Washington
funded the flight experiment as part of its hypersonic research
effort.