UAB seniors engineer solution for NASA cryogenic freezer

Project leads to more efficient insulation and use of manpower for GLACIER.

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Senior Design Group: standing from left are Jeffery Black, Logan Beane, Brandon Kirkland and Justin Terrell. Seated is Amanda Haglund.

They were about 5 years old when Buzz Lightyear’s catchphrase – “To infinity and beyond!” – was adopted by a generation of youngsters. Now, a group of students at the University of Alabama at Birmingham are living their childhood fantasies of working toward a space-based existence.

School of Engineering students Logan Beane, Jeffery Black, Amanda Haglund, Brandon Kirkland and Justin Terrell designed a test fixture for evaluating cryogenic insulation materials as part of an engineering senior design project. Their work revealed glass microspheres, hollow borosilicate glass spheres approximately the diameter of a human hair, are a more efficient thermal insulation solution than the current technology for the NASA GLACIER cryogenic freezer designed, which was previously developed by the UAB Center for Biophysical Sciences and Engineering.

The microspheres will be incorporated into future GLACIER units and other CBSE projects pending approval from NASA officials at the Johnson Space Center in Houston.

“The more collaboration with local industry, the better chances for students to have a job when they graduate. And working with quality students on projects means businesses have free help finding real-world solutions. It is win-win.”

“The students took a real-life project and problem that needed to be resolved for the next generation of CBSE cryogenic freezers, and they made it happen in two semesters,” says Lee Moradi, Ph.D., P.E., director of engineering at the CBSE.

“The business community needs to build more relationships like this project,” Moradi says. “The more collaboration with local industry, the better chances for students to have a job when they graduate. And working with quality students on projects means businesses have free help finding real-world solutions. It is win-win.”

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From left: Jud Dunlap, Lee Moradi and Brandon Kirkland

Air in the NASA GLACIER is circulated through a heat exchanger insulated by a combination of aerogel blankets and vacuum pressure called the GLACIER vacuum jacket. The aerogel blanket has to be measured, cut and wrapped section by section around the complex geometry of the heat exchanger until it’s filled as tightly as possible. This process is tedious and the insulation potential depends highly on installation technique.

CBSE scientists believed the microspheres would be an improvement over the aerogel blanket and asked UAB students to design and fabricate a test chamber that replicates the heat exchanger.

The students tested both materials at varying vacuum pressures. Steady state temperatures were recorded by platinum resistance temperature detectors and revealed glass microspheres as the better option.

The UAB students also reported another energy advantage for glass microspheres when compared with the aerogel blanket — manpower. It took weeks to wrap the internal heat exchanger with the blanket, but only days to fill the insulation region with the microspheres.

Kirkland said testing revealed glass microspheres offered a significant insulation improvement at GLACIERs operating conditions for two reasons. “First, they have better thermal performance in the high-vacuum environments. Second, they flow like a liquid, so the insulation potential can be maximized.”

“Oftentimes in engineering, students don’t understand and anticipate potential issues that can occur during the design process because of limited, first-hand experience. The students deserve much credit for quickly identifying issues associated with configuring the different insulation materials in GLACIER and also for understanding the way the entire system works,” says CBSE systems engineer Jud Dunlap, who mentored the students with research engineers David Ray and Lance Weise.

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