The Cryogenic Refuge Alternative Supply System (CryoRASS), and a smaller liquid air-filled backpack under development at NASA Kennedy Space Center’s (KSC) Biomedical Lab, have the potential to store more than twice the amount of breathable air than traditional compressed gas systems.

KSC lead engineer David Bush works on a prototype of a CryoRASS. (NASA/Jim Grossmann)

KSC lead engineer David Bush and teams from BCS Life Support, URS Corp., and InoMedic Health Applications began working on the two systems in September 2012. The National Institute for Occupational Safety and Health (NIOSH) is funding both projects in the hopes that the liquid air-based systems could change the way coal miners seek refuge or flee from underground disasters.

“Currently, mines use big tube banks of compressed air with no cooling. Our solution uses smaller, lower-pressure dewars of liquid air with cooling,” said Bush.

The Agency has used the cryogenic technology in its rescue crew SCAPE suits, short for Self-Contained Atmospheric Protective Ensemble, since the Mercury Program in the 1960s. CryoRASS and the backpack, called CryoBA, work by drawing air into a closed environment, then vaporizing and circulating it back to the user. Bush describes the systems as “passive air conditioners,” and said initial demos show a drop in temperature by about 15 degrees.

Many refuge chambers are designed to provide up to 96 hours of breathable air, but Bush said CryoRASS could easily exceed the minimum requirements, allowing more time for the miners to be rescued. Another plan being discussed is to build refill stations in mines spaced about 90 minutes apart, so that crews could walk out of a disaster situation with their personal CryoBA backpacks.

As Bush and his team continue to advance and refine the cryogenic technology, they are gaining some attention from the agency’s newest human spaceflight programs.

“In an emergency situation, rescue crews will have to go up some sort of launch structure, pull a crew out of a confined capsule, and get them to safety all within the span of their breathing device,” Bush said. “We did a rescue dry run with a mock Orion capsule and, because the entryway is small, having a device with a smaller profile that is more efficient with the weight-to-space ratio is helpful.”

Cryogenic Refuge Alternative Supply System (CryoRASS)

BCS Life Support (Deland, FL)
LabTech (Tampa, FL)
URS (San Francisco, CA)

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NASA Tech Briefs Magazine

This article first appeared in the December, 2013 issue of NASA Tech Briefs Magazine.

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