Airbag Designer Casts Eye on NASA's Escape Ship
Newairbag technology that mimics nature'sway of protecting seed embryos could take the bumps out of spacecraftlandings.
Thesystem consists of four cylinder-shapedair sacs designed to fully inflate during launch and landing, and to bepartially inflated in between, providing seating for the astronautsduringtheir flight. So far, tests of the 700-pound prototype, using a dummy,have encouraged its developer, who plans to present hisresults to NASAthis fall.
Thenature-inspired sacs are being developedfor Orion,the space capsule that was originally part of NASA's Constellationprogram tosend astronauts back to the moon. With moon missions nolonger on NASA's agenda, Orion will be used only as an escapeship to carryastronauts home from the International Space Station in an emergency.
Asan emergencyvehicle, Orion will need to be prepared for the unexpected ?landing onearth instead of in the ocean. The original 1,100-pound system designedtoprotect Orion astronauts during a water landing would be too heavy forland:Essentially, the ground offers little shock absorption, and more weightwouldmean more damage upon impact, according to Sydney Do, lead developer ofthe newsystem.
"Theadvantage of an airbag-type systemis that it can perform this same function but with a lighter system,"saidDo, a graduate research assistant at the Massachusetts Institute ofTechnology.
Biomimicry
Do'sbio-inspiration blossomed from the innerworkings of seeds, where a fluid called endosperm surrounds andprotects theembryos from impact when being dispersed by wind or other means.Instead ofendosperm, Do and his team used air.
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"Theidea was to treat each occupant asan 'embryo' and surround them in a personal airbag consisting of air,"Dotold TechNewsDaily.
"Whencrew positioning andimpact-protection requirements were considered in the system design,this ideaeventually evolved into an 'airbag seat' and then finally to a seatsupportedby airbags."
Basicallythe system consists of a seatsurrounded by four cylindrical airbags? each about the size of two vertically stacked pickup-truck tires ?arrangedin a 2x2 configuration.
Dummytesting
Totest the prototype, Do first created acomputer model to analyze how characteristics such as airbag size wouldaffectthe system's protective capabilities. Next, he constructed a seatsurrounded byfour airbags made of Vectran, a high-strength synthetic fiber used fortheairbags encasing rovers that landed on Mars.
Dothen performed real-life drop tests toverify his mathematical model. A dummy was attached to the prototypeanddropped from different heights to simulate the velocity an astronautwouldexperience just before impact. These dummy drops led to the design ofspecialvalves to allow the cylindrical airbags to vent air during impact.
Theresult: The airbag system survived dozensof drops, indicating the technology should work for an Orion landing.
However,there is still work to do, Do said.While the drop-testing was successful, the results show theeffectivenessof the airbag system only for vertical drops. If Orion descended at anangle,the system could fail.
Theproject was funded by NASA and Do willpresent his results to the space agency this fall.
This article was provided by TechNewsDaily, asister site of SPACE.com.
