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NASA to test IRVE-3 inflatable reentry system


June 17, 2012

NASA inflatable reentry vehicle during plasma phase of Mars landing (Image: NASA)

NASA inflatable reentry vehicle during plasma phase of Mars landing (Image: NASA)

Image Gallery (13 images)

Your spacecraft is falling from the skies at an initial speed of Mach 25. Your reentry heat shield, that has to survive a 7,800 degrees Celsius (14,072° F) plasma shock, is a finely tuned hi-tech amalgam of refractory metals and carbides and reinforced carbon-carbon ablation materials. Care to replace your mighty heat shield with a balloon? Not likely! But that is exactly what NASA is considering.

This summer, the third in a series of NASA suborbital test flights will attempt to demonstrate the feasibility of inflatable spacecraft. The Inflatable Reentry Vehicle Experiment (IRVE-3) is scheduled for a suborbital test flight from the Wallops Flight Facility on Virginia's Eastern Shore later this northern summer. Part of the Hypersonic Inflatable Aerodynamic Decelerator (HIAD) project within NASA's Office of the Chief Technologist's Game Changing Development (GCD) Program, IRVE-3 is one of NASA's many projects to develop new technologies to advance space travel.

Cutaway image of 3-meter diameter IREV3 inflatable reentry test vehicle following inflation (Image: NASA)

Why a balloon? Balloons – even those designed to withstand the rigors of reentry from orbit – are small and light. Past use of aerodynamic decelerators required that the rigid structures fit within the launch rocket. In contrast, IRVE-3, while three meters (9.8 ft) in diameter when inflated, packs into a 56 cm (22 in) diameter cylinder, which is three meters long. The complete payload will be launched by a Black Brant sounding rocket.

Black Brant sounding rocket at launch (Photo: NASA)

During the flight, the tubes will be inflated, thereby stretching a thermal protection system (TPS) blanket that covers the tubes. The result is an aeroshell with a heat shield that will protect an active payload returning to Earth, while having the advantage of being much easier to launch to orbit. Also, with a total mass of about 100 kg (220 lb), the inflatable aeroshell is far lighter than a rigid aeroshell.

Inflation sequence for IREV3 test vehicle once delivered into space (Image: NASA)

The flight plan for the IRVE-3 test includes climbing to a maximum altitude of 462 km (287 miles), at which point the IRVE-3 separates from the Black Brant, and is inflated. The inflated reentry vehicle and its payload will then fall back to Earth, reaching a downward velocity in excess of 2.5 km/s (1.5 miles per second) before the atmosphere becomes sufficiently dense for drag braking to start.

IREV3 inflatable reentry test vehicle being subjected to reentry thermal and dynamic conditions (Photo: NASA)

Testing has been a major part of this development effort from the beginning. Although the most visually impressive test was that shown above to test the thermal and dynamic response of the inflated reentry vehicle, perhaps the most important was a complete systems test of the IRVE-3 and its payload in near-vacuum conditions.

IREV3 inflatable reentry test vehicle being inspected following inflation in the NASA's Transsonic Dynamics Tunnel (Photo: NASA/Sean Smith)

This test confirmed that the IRVE-3 release and inflation mechanisms functioned properly, as did the data acquisition and transmission electronics. "There are an awful lot of complex systems packed inside the payload on IRVE-3," said Robert Dillman, the chief engineer for IRVE-3. "When it works, it looks simple and that's a good thing. But there are a lot of internal parts that have to work together in order to make that simple function achievable."

If flight tests continue to be satisfactory, one potential application for inflatable reentry vehicles other than planetary probes is emergency evacuation of the International Space Station and other future manned orbital stations. Individual reentry survival mechanisms were first proposed in the early 1960s with the MOOSE (Man Out Of Space Easiest) concept from General Electric.

Artist's conception of the ill-fated General Dynamics MOOSE individual reentry system (Image: NASA)

Although GE performed preliminary testing on some of the components of the MOOSE system, neither NASA or the U.S. Air Force was interested – probably rightly so. Modern techniques and materials developed during the IRVE development and testing program could well make the issuing of inflatable survival vehicles a standard part of space flight contingency planning in the future.

Here's a video simulation of the upcoming test.

Source: NASA

About the Author
Brian Dodson From an early age Brian wanted to become a scientist. He did, earning a Ph.D. in physics and embarking on an R&D career which has recently broken the 40th anniversary. What he didn't expect was that along the way he would become a patent agent, a rocket scientist, a gourmet cook, a biotech entrepreneur, an opera tenor and a science writer. All articles by Brian Dodson

Imagine if the inflatable shield was in the shape of a disk that was rotating about the axis of the payload. Would the magnus effect (or is it coanda effect) give some lift to slow down the descent further?

Joseph Thomas

If you filled a large enough heat shield with a lighter than air gas the whole vehicle could be lighter than air requiring only trivial amount of additional power to arrive at a precise destination.


there is a strong chance this system will turn 180 degrees in the direction where its entering.. at-least 3 times out of 10.. and not by just probablity there are more then one reasons to it..

1) front of projectile is lighter

2) front is having less density than every where else

3) aerodynamically there is a very very strong chance that this design will react the same way as the parachute does i.e projectile at front & air blocking lighter stuff at the end

4) forget #1 #2 & #3 even with atmosphere or gravity this thing is gonna turn because of wrong distribution of "mass" and "moment of inertia"

the only chance of it to work correctly is with hundreds of gyro sensors & stabilizers will work together/without-flaw.. which is not a perfect way

the correct way is an egg(oval ie with two radius) shaped design, with craft at the diameter axis of bigger circle & and open hemisphere second(smaller) circle ..

with back second circle of dynamic radius... to manually increase the air friction...

Imran Sheikh

re; Imran Sheikh

You have taken wild guess on where the center of mass is. My experience is that cones are self stabilizing. For active stabilization you need 1 gyroscope (3 ring) and 4 attitude jets. You could build a mechanically linked system but except for a very few low probability eventualities digital computer controls are easier.


It is worth noting that the inflation system is in the tail end of the craft, so during inflation you will actually move the center of mass forward from it's initial location (unknown to me) which will add to overall stability.

There might be gyros and some small attitude jets involved in the test, but given the configuration of the craft it could not be carrying too much Delta-V.

I think the most interesting part is at 1:10 in the above video, it appears that the main body of the craft can shift on at least one axis to cause a change in direction. Yep, NASA has just invented Space Surfing(tm), talk about a big wave! My money says within 25 years we will have an eccentric thrill-seeker attempt this in person.

More info over here (

Rich Brumpton

@Imran Sheikh

NASA has a whole team on this , simulations calculations studies etc but they missed a fundamental point that you were able to pick right out and you were able to give us the probability of failure as well.

They really need to get you in on the ground floor to get them pointed in the right direction from the start.


I thought of this! I screamed to NASA that balloons would be the best parachute and deceleration device going to Mars, since balloons would get resistance (thus slowing) with far less atmosphere farther out, and that capture to the atmosphere by rolling from atmosphere surface tension could eliminate heat-shield fiascos, and similarly coming home. Looks like somebody at NASA was listening--they also listened to my inflatable micrometeor shield that Bigalow bought and incorporated into their reinvention of the Goodyear wheel. NASA checked out my windmills for Martian power idea, too, but I haven't seen one on a Mars rover yet, nor have I seen my balloons over Mars idea come to any fruition, but we can dream, can't we? Meanwhile I hope NASA finally sends a rover to discover the fate of the Beagle.

Ross Nicholson

Hopefully this will prove useful for landing large loads on Mars efficiently without having to rely so much on heavy rocket thrusters to decelerate when landing.

Stephen Colbourne
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