Purdue engineers help develop refrigerator for space travel

Engineers from Purdue University, Whirlpool Corp. and Air Squared Inc. have developed a refrigerator prototype to help solve the problem of astronauts not having a fridge to store food for long missions.

A few attempts have been made to design a fridge for space travel since the 1969 moon landing. Some of the prototypes actually made it into space, but none of them worked as desired for longer trips.

“NASA had tested three fridges in the 1990s on space shuttles,” said Leon Brendel, a Purdue mechanical engineering doctoral student. “The documentation of those shows that their performance was rather low and that maintenance was needed almost after every flight. In the 2000s, a refrigerator in space even stopped operating.”

As it stands, when astronauts travel into space, they take canned and dried food with them that can last up to three years. With Purdue’s current project, the goal is to lengthen the shelf life of food in space from three years to five or six years. That would allow longer trips in space.

“[The refrigerator] particularly supports long-manned trips where large food supplies are needed,” Brendel said. “For such spacecraft, an energy-efficient fridge will reduce the required solar panels and radiators, thus reducing the overall mass of the spacecraft.”

The project is being funded by NASA’s Small Business Innovation Program. Purdue will receive $295,000 over four years as a subcontractor for Air Squared.

A team of engineers has conducted experiments with the fridge prototype in Virginia at ZERO-G’s weightless research lab plane, the only one of its kind in the country. Three experiments were conducted while in the lab during four separate flights. The flights each flew in microgravity 30 times at 20 second intervals.

The team has made sure the fridge has met certain requirements during experiments in order for it to be successful in space without breaking down. 

First, it needs to be able to function in any position so astronauts do not need to worry about keeping the fridge upright. Secondly, the fridge should not demand the use of oil. Without oil, astronauts will not need to be concerned about the oil supply not flowing properly as they travel.

So far, the experiments have shown positive results. The prototype has proven that it can operate in both microgravity—or the absence of gravity—and on the ground with equal efficiency. 

Whirlpool, which worked alongside Air Squared, contributed to the creation of building the fridge prototype.

Alberto Gomes Sr., principal engineer of advancement development and innovation at Whirlpool, has described the company’s involvement as providing knowledge “on how to design a reliable and simplified refrigeration system for use in space, as well as … expertise on what size and what architecture needs to be used in order to meet NASA requirements for the short, medium and long term.”

This isn’t the first time Whirlpool has been involved in making technology for use in space.

“Before the momentous landing on the moon on July 20, 1969, there were a lot of logistical problems that NASA had to deal with, not only with how the astronauts were going to get there, but how they were going to eat, sleep and perform all the other functions that necessitate daily human life,” Whirlpool communications manager Cean Burgeson said. “That’s when the U.S. government turned to Whirlpool to create the world’s first space kitchen and space food.”

In total, Whirlpool helped on 300 space-related contracts between 1957 and 1973 alone, and has helped on missions such as Apollo, Gemini and Skylab.

Regarding the current Purdue-Whirlpool project, Brendel said that a final product could be ready in two years. However, actual usage in space depends on the schedule and priorities of NASA.

The type of food that could be sent with astronauts into space will also be determined by NASA, but Brendel said that refrigeration will allow space travelers to consume a broader variety of food.