In space, nobody can hear you scream (when you’re craving a cold drink). Jokes aside, we just got an update that from Purdue University about something interesting. They are working with Air Squared Inc, and the Whirlpool Corporation to build a prototype of a refrigerator that could be used to keep food cold and longer fresh for the astronauts on space stations or in shuttles for long missions.
Why is this relevant? Because, on one hand, canned and dried food has a shelf life of only about three years, and on the other hand, traditional fridges don’t work properly in space. This project that is on the way now is funded by NASA’s Small Business Innovation Research (SBIR) program and they have the target to make food last up to six years.
Testing as realistically as possible
In order to verify their prototypes, they ran a series of experiments within a Zero-G plane earlier this month. The planes from Zero Gravity Corporation are able to create a microgravity environment by taking a nose-dive from a high altitude to a lower altitude. In order to get data for their research, they did this 30 times, 20 seconds long per attempt.

After assessing all the information they could gather, the team has come back with two revelations that will help them taking this project to the next stages safely. The first important outcome was that they could verify that their prototype could operate in microgravity just like on the ground. The second new information was that there is no increased risk of the machine flooding in microgravity, which is important because liquid flooding could damage the fridge.
Thoughts from the project team
“We want to have a refrigeration cycle that is resistant to zero gravity and works to normal specifications,” said Eckhard Groll, a professor and head of Purdue’s School of Mechanical Engineering. “Our preliminary analysis clearly shows that our design allows gravity to have less impact on that cycle.”
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“The fact that the refrigeration cycles operated continuously in microgravity during the tests without any apparent problems indicates that our design is a very good start,” said Leon Brendel, a Purdue Ph.D. student in mechanical engineering. “Our first impression is that microgravity does not alter the cycle in ways that we were not aware of when we tested the effects of gravity on the fridge design on the ground by rotating and inclining it.”

“Floating around with the experiments is kind of like swimming, except that you don’t have resistance around you and you have to work to get the data at the same time. It was pretty fun, but I had to remember to not get cocky,” said Paige Beck, who had the challenge of holding herself in place to collect data from an experiment at regular intervals and simultaneously record her actions into a microphone.
“Sometimes I was too slow! But you learn as you go, and we successfully got the data we needed,” Brendel said. The team will continue to analyze their findings. Projects like these, with the aim to provide a long-term habitat to astronauts, could help with some challenges if mankind sets out to Mars or elsewhere. To get a better idea of how the testing went like, watch the video below with footage from within the plane.
YouTube: Testing a Fridge Prototype in Microgravity
Photo credit: The material shown has been prepared by Stephen Boxall for ZERO-G and the Whirlpool Corporation.