For NASA astronauts, a new kind of airbag system
We may have gotten better at sending astronauts to the Moon, but bringing them back continues to be a challenge.
MIT researcher Sydney Do has devised a reusable, 700-lb. airbag system that inflates during launch and landing and deflates for storage.
The application at stake is NASA's Orion capsule, which was originally intended to return humans to the Moon by 2010 as part of the agency's Constellation program. Though the program was scrapped in February as a result of budget cuts, the capsule remains, now serving as an emergency escape vehicle to be docked at the International Space Station.
Orion was originally designed to land on water, and its crew seats are mounted on a stiff structure supported by shock absorbers, just like the Apollo program. But Orion is heavier, at 1,100 lbs., and its design is not supportive enough to handle the possibility of an emergency landing on terra firma.
Do's system is lighter than the one NASA originally proposed, but more importantly, it's mechanical and not digital -- avoiding a computer-originated problem in an emergency situation.
Inspired by the structure of seeds, in which fluid surrounds an embryo to protect it, Do's system surrounds the astronaut in a cushion of air.
Participating in a collaborative project by MIT and Pennsylvania State University students (funded by NASA's Engineering and Safety Center), Do learned that the timing of releasing gas from an airbag is key -- that is, underinflation causes impact, while overinflation causes a dangerous bounce in the other direction.
What the researchers found is that some, but not all, the gas must be vented to strike the right balance between over- and under-inflation. The solution: valves that are designed to open at low pressure.
Do tested the design of the valve and developed a computer model to analyze how different variables, such as the size of the airbag, would affect the risk of astronaut injury upon impact.
The resulting full-size prototype is designed to protect one astronaut with four Vectran airbags, each measuring 1 ft. by 2 ft. with two 6-in. wide valves.
Earlier this month, Do conducted a series of drop tests with a crash dummy that measured the acceleration of each drop. He plans to present his final design to NASA later this fall. If Orion never lifts off, his research is likely to inform private space ventures.
The next question: what does an astronaut do if one or more valves fail?
Photo: William Litant
This post was originally published on Smartplanet.com