Inflatable shells could ensure safe landings for spacecrafts on Mars

London, August 12 (ANI): NASA is planning to test inflatable shells for spacecraft traveling to Mars in the future, so as to ensure safe landings on the Red Planet.

Before NASA's Mars Science Laboratory alights on the red planet in 2012, the one-tonne rover will have fallen through Mars' thin atmosphere at hypersonic speeds and blistering temperatures.

Every inch of the craft must be protected by a rigid aeroshell, which bears the brunt of the fastest portion of the descent before parachutes and retrorockets take over.

NASA engineers are confident that the craft will survive its current mission.

But for missions with much heavier payloads, they will need something better.

"We're kind of at the limit for what we can do," Neil Cheatwood, of NASA's Langley Research Center in Hampton, Virginia, told Nature News.

Engineers then wouldn't have to squeeze rigid aeroshells into rockets, which are limited to about 5 metres in diameter.

In some of the designs, the inflatable shell would trail the payload as a 'ballute', a mixture between a balloon and a parachute.

In others, the aeroshell would simply be replaced by a giant, mushroom-shaped foreshell.

On August 17, NASA will test an inflatable aeroshell that according to Cheatwood, the test's project scientist, could provide the proof of principle needed to incorporate the technology in future Mars missions.

These could include a sample return or a human mission, which will need to take to Mars the means - and extra weight - of getting back to Earth.

The test launch, from the Wallops Flight Facility on Virginia's eastern shore, will take the aeroshell up on a Black Brant 9 sounding rocket. Less than four minutes after launch, the payload would reach a peak at 211 kilometers.

A minute later, a cannister of nitrogen would inflate the shell to a 3-metre-wide saucer shape seven times the diameter of the rocket.

"Only recently have materials been developed that can survive the heats experienced during re-entry," said Cheatwood.

This aeroshell will have a woven exterior made from a heat-resistant ceramic that caps cells made from strong Kevlar fibres.

According to Adam Steltzner, manager for the Mars Science Laboratory's entry, descent and landing systems at the JPL, the existing system should even work for a Mars sample return.

But to get humans back from Mars - missions that would need to land tens of tonnes on the surface - the entry systems will need some puffing up.

"North of two metric tonnes, we're going to need some help," he said. (ANI)