posted 08-11-2009 12:12 PM               

Rocket to Launch Inflatable Spacecraft Shell

Inflatable aircraft are not a new idea. Hot air balloons have been around for more than two centuries and blimps are a common sight over many sports stadiums. But it's hard to imagine an inflatable spacecraft.

Researchers from NASA's Langley Research Center in Hampton, Va., are working to develop a new kind of lightweight inflatable spacecraft outer shell to slow and protect reentry vehicles as they blaze through the atmosphere at hypersonic speeds.

They will test a technology demonstrator from a small sounding rocket to be launched at NASA's Wallops Flight Facility at Wallops Island, Va. The launch is scheduled for Aug. 17.

Credit: NASA/Sean Smith

The Inflatable Re-entry Vehicle Experiment, or IRVE, looks like a giant mushroom when it's inflated. For the test, the silicon-coated Kevlar aeroshell is vacuum-packed inside a 16-inch (40.6 cm) diameter cylinder, but once it unfurls and is pumped full of nitrogen it is almost 10 feet (3 m) wide.

Engineers say the concept could help land bigger objects on Mars. "We'd like to be able to land more mass on Mars," said Neil Cheatwood, IRVE's principal investigator and chief scientist of the Hypersonics Project within NASA's Fundamental Aeronautics Program. "To land more mass you have to have more drag. We need to maximize the drag area of the entry system. We want to make it as big as we can, but the limitation has been the launch vehicle diameter."

According to Cheatwood, the idea of inflatable decelerators has been around for 40 years, but there were technical issues, including concerns about whether materials could withstand the heat of re-entry. Since then materials have advanced and because of numerous Mars missions, including rovers, landers and orbiters, there's more understanding of the Martian atmosphere.

That means researchers can now test a subscale model of a compact inflatable heat shield with the help of a small two-stage rocket. The vehicle is a 50-foot Black Brant 9 that will lift IRVE outside the atmosphere to an altitude of about 130 miles (209 km). Engineers want to find out what the re-entry vehicle will do on the way down.

"The whole flight will be over in less than 20 minutes," said Mary Beth Wusk, IRVE project manager. "We separate from the rocket 90 seconds after launch and we begin inflation about three-and-a-half-minutes after that. Our critical data period after it inflates and re-enters through the atmosphere is only about 30 seconds long."

Cameras and sensors on board will document the inflation and high-speed free fall and send information to researchers on the ground.

After its brief flight IRVE will fall into the Atlantic Ocean about 90 miles down range from Wallops. No efforts will be made to retrieve the experiment or the sounding rocket.

The Inflatable Re-entry Vehicle Experiment is an example of how NASA is using its aeronautics expertise to support the development of future spacecraft. NASA's Aeronautics Research Mission Directorate in Washington funded the flight experiment as part of its hypersonics research effort.

posted 08-17-2009 02:46 PM               

NASA Launches New Technology: An Inflatable Heat Shield

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.

Credit: NASA/James Wingfield

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.

"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.

posted 07-23-2012 09:33 AM               

NASA Successfully Tests Hypersonic Inflatable Heat Shield

A large inflatable heat shield developed by NASA's Space Technology Program has successfully survived a trip through Earth's atmosphere while travelling at hypersonic speeds up to 7,600 mph.

The Inflatable Reentry Vehicle Experiment (IRVE-3) was launched by sounding rocket at 7:01 a.m. Monday from NASA's Wallops Flight Facility on Wallops Island, Va. The purpose of the IRVE-3 test was to show that a space capsule can use an inflatable outer shell to slow and protect itself as it enters an atmosphere at hypersonic speed during planetary entry and descent, or as it returns to Earth with cargo from the International Space Station.

"It's great to see the initial results indicate we had a successful test of the hypersonic inflatable aerodynamic decelerator," said James Reuther, deputy director of NASA's Space Technology Program. "This demonstration flight goes a long way toward showing the value of these technologies to serve as atmospheric entry heat shields for future space."

IRVE-3, a cone of uninflated high-tech rings covered by a thermal blanket of layers of heat resistant materials, launched from a three-stage Black Brant rocket for its suborbital flight. About 6 minutes into the flight, as planned, the 680-pound inflatable aeroshell, or heat shield, and its payload separated from the launch vehicle's 22-inch-diameter nose cone about 280 miles over the Atlantic Ocean.

An inflation system pumped nitrogen into the IRVE-3 aeroshell until it expanded to a mushroom shape almost 10 feet in diameter. Then the aeroshell plummeted at hypersonic speeds through Earth's atmosphere. Engineers in the Wallops control room watched as four onboard cameras confirmed the inflatable shield held its shape despite the force and high heat of reentry. Onboard instruments provided temperature and pressure data. Researchers will study that information to help develop future inflatable heat shield designs.

After its flight, IRVE-3 fell into the Atlantic Ocean off the coast of North Carolina. From launch to splashdown, the flight lasted about 20 minutes. A high-speed U.S. Navy Stiletto boat is in the area with a crew that will attempt to retrieve IRVE-3. The Stiletto is a maritime demonstration craft operated by the Naval Surface Warfare Center Carderock, Combatant Craft Division, and is based at Joint Expeditionary Base Little Creek-Ft Story, Va.

"A team of NASA engineers and technicians spent the last three years preparing for the IRVE-3 flight," said Lesa Roe, director of NASA's Langley Research Center in Hampton, Va. "We are pushing the boundaries with this flight. We look forward to future test launches of even bigger inflatable aeroshells."

This test was a follow-on to the successful IRVE-2, which showed an inflatable heat shield could survive intact after coming through Earth's atmosphere. IRVE-3 was the same size as IRVE-2, but had a heavier payload and was subjected to a much higher re-entry heat, more like what a heat shield might encounter in space.

IRVE-3 is part of the Hypersonic Inflatable Aerodynamic Decelerator (HIAD) Project within the Game Changing Development Program, part of NASA's Space Technology Program. Langley developed and manages the IRVE-3 and HIAD programs.