Inflatable heat shield may protect spacecrafts entering planets' atmospheres

London, August 20 (ANI): Scientists have successfully tested an inflatable heat shield, demonstrating for the first time that these light, flexible devices could be used to protect spacecraft on their way through planets' atmospheres.

Other spacecraft use solid heat shields that either drop away as the spacecraft near the surface, as happened with the Mars rovers, or gradually erode in the atmosphere.

But, according to a report in New Scientist, these solid shields are heavy, and their weight limits the mass of the spacecraft they are designed to protect, since both must launch on the same rocket.

Their physical size is also limiting, since the shields must be small enough to fit inside a launch rocket.

Balloon-like shields can in theory sidestep these issues, since they are lightweight and can inflate to relatively large sizes after being folded up during launch.

These weight and size savings allow for heavier spacecraft payloads.

The new shield, called the Inflatable Re-entry Vehicle Experiment (IRVE), launched aboard a small rocket on Monday morning from NASA's Wallops Flight Facility on Wallops Island, Virginia.

It was the first successful test of an inflatable heat shield.

"We're totally thrilled with the data results we've received," said project manager Mary-Beth Wusk of NASA's Langley Research Center in Hampton, Virginia.

The launch rocket shot up 218 kilometres in about four minutes before detaching from the 40-kilogram shield.

The shield was packed into a 40-centimetre-wide shroud for takeoff, but puffed out to a mushroom-shaped pillow that spanned 3 metres when filled with pressurised nitrogen.

After it parted from the rocket, IRVE and its payload, which included navigation and data-collecting electronics, plunged back into the Earth's atmosphere at hypersonic speeds.

Engineers expected it to reach Mach 5, about 1.7 kilometres per second, though they won't be certain of its actual speed until they finish analysing the data.

The shield is made of several layers of heat-resistant fabric woven from thin strands of ceramics. This covers an inner pouch of silicon-coated Kevlar, which holds the balloon-like shape.

The design resembles a device known as a "ballute", a cross between a balloon and a parachute. Ballutes sport inflatable pouches, like IRVE, but not its flexible outer layer.

"The NASA test is significant in that it's the most advanced test yet of an inflatable heat shield for re-entry applications," said Jason Andrews, president of Andrews Space.(ANI)