A group of UAB engineers has gained wide recognition in recent years for its work on building freezers that can maintain extreme cold temperatures in space. Now that same group has refined its focus to tackle a new challenge— designing a rapid-freeze unit that could potentially influence the types of science performed in space.
The Engineering and Innovative Technology Development (EITD) team in the School of Engineering recently received a pair of new contracts from NASA worth a combined $3.6 million to develop rapid-freeze technology and hardware for use on missions to the International Space Station (ISS).
The contract seems like a natural fit for EITD, which has worked with NASA for more than 10 years developing the high-tech cold-stowage units MERLIN, GLACIER, and Polar—all of which are currently in use aboard the ISS. However, EITD director Lee Moradi, Ph.D., says the ability to rapidly freeze biological samples requires a fundamentally different approach, and UAB was one of several “high-profile” research entities that submitted proposals.
“The capability to rapidly freeze biological samples on the ISS to preserve the microgravity effects has long been a priority,” Moradi explains. “To freeze a biological sample in normal, ground-based research, a scientist will dip the sample into liquid nitrogen. They don’t maintain liquid nitrogen stores on the ISS, so the intent of the NRA (NASA Research Announcement) was to find a safe, efficient alternative.”
The challenges posed by the NRA were complex. Not only did NASA need a new rapid-freeze technology, it needed hardware that would be capable of transporting the samples to and from the ISS. “The NRA was asking for a lot in terms of what one system could handle,” says EITD team member Rob Rouleau. “We responded with two separate proposals; one for the transport and one for working in orbit. We thought we might get a contract for one or the other, so we were thrilled to find out we’d gotten both.”
In its previous cold-stowage projects, the EITD team has built and maintained a range of freezer units capable of storing samples at temperatures as low as negative 160 degrees Celsius. Even with the capability for such extreme cold, however, researchers in orbit still have a need for a rapid-freeze technology that can offer the same advantages as liquid nitrogen.
“Thinking of it in terms of a household refrigerator, if you move something into the freezer, it may take hours or days to completely freeze,” says Moradi. “During those hours, the sample is changing biologically—on a molecular level—throughout the freezing process.”
“The freeze rates from our unit will stop the cell growth, so we’re preserving microgravity effects on the sample that can then be studied on the ground,” explains Ashlyn Manzella. “The current technologies take several minutes, even though the temperatures can get similarly close. With these freeze rates, this could potentially open up the types of science that they can do on the ISS.”
A key factor in designing a rapid-freeze technology for the ISS is efficiency. Considering the enormous amount of energy required to maintain the instruments on board the station, energy efficiency is a prime consideration. “Our GLACIER and Polar units provide transport at minus 95 degrees Celsius using 75 watts,” says team member David Cooper. “Our rapid-freeze system will provide transport at minus 160 degrees at the same power levels.”
“If you light a 75-watt bulb in a dark room, you can hardly see, but that’s the amount of energy this unit will use to maintain those low temperatures,” says Moradi. It’s incredibly energy efficient.”
Building for the Future
In addition to the development of the rapid-freeze system, the EITD team will perform flight integration and operations activities, which will include development of planning models and crew procedures and training, among many other responsibilities.
The EITD team that will be leading the project includes Cooper, Manzella, Brittney Macon, Jud Dunlap, Joshua Dunn, and Lance Weise. All of the team members have wide-ranging experience working on cold-stowage projects as well as other research efforts, but this is the first time that members of that group will take the lead on a high-level contract—a milestone Moradi says was by design.
“No one at EITD is pigeon holed into just one area,” Moradi says. “Everyone works on a variety of projects, so our young researchers get good experience. But for that experience to pay off long-term, they also needed to get experience writing proposals. This was an attractive contract for EITD to pursue, because we knew that the young researchers we have on this team would be in a good position to write a competitive proposal. Now that they’ve won the contract, they’ll get the experience of leading the project.”