The giant doughnuts that could help a Mars landing (BBC)
Last edited Wed Mar 12, 2014, 04:31 PM - Edit history (2)
Richard Hollingham
At an isolated facility in the Mojave Desert, protected by two security checkpoints and patrolled by armed guards, Nasa is conducting an experiment to help shape humanity’s future in space. Inside a vast harshly-lit hangar, surrounded by monitors, cables and test equipment, I watch as technicians attach wires to a giant inflatable doughnut.
It appears that either staff at the agency’s Dryden Flight Research Center have got their hands on some weird alien artefact or are constructing a surrealist art installation. In fact this six-metre wide air-filled ring is a small section of a spacecraft landing system known as a Hiad – Hypersonic Inflatable Aerodynamic Decelerator.
“You’ve seen one of the doughnuts,” says Neil Cheatwood, who leads the Hiad project. “Imagine a stack of doughnuts forming a pyramid – like the hats the [cult ‘80s] musical group Devo used to wear.” (Devo’s said headwear even has its own Wikipedia page)
Cheatwood is attempting to tackle a fundamental problem with landing astronauts on Mars or returning them to Earth from other worlds: current spacecraft designs would not make it to the ground in one piece. They would be coming too fast and getting too hot, smashing into the ground or burning up in the atmosphere. The existing technologies used for heatshields – also known as aeroshells – are not up to the task.
Capsules returning to the ground from orbit, such as the Russian Soyuz or the privately funded SpaceX Dragon, are protected by heat shields designed to withstand entering the atmosphere at around 7.5km per second. But astronauts coming back from the Moon are travelling at 11km per second; from Mars they would be going at a phenomenal 14km per second.
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more: http://www.bbc.com/future/story/20140311-giant-doughnuts-for-mars-landing
Interesting; I didn't realize that there would be a problem with current heat shield designs.
(Those are known as "energy domes", BTW.)
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