Prototypes: Experiments in Microgravity
Four students took the ride of a lifetime in June aboard a NASA plane flying parabolic maneuvers over the Gulf of Mexico to achieve 30-second bursts of zero-gravity conditions.
“As the plane rose to the top of the parabola, the cabin went from experiencing 2 Gs of force to zero Gs. All of a sudden I just felt my body floating up in the air,” says Broghan Cully ’11. “At first it is an uneasy feeling because your brain just has no sense of orientation. However, after the initial shock, it was absolutely incredible to be floating around.”
Cully and fellow fliers Sean Currey ’11, Max Fagin Th’11, and Michael Kellar Th’11 were participating in NASA’s Microgravity University, which offers students the chance to conduct experiments in a space-like environment. The team tried out a project they completed for ENGS 89/90 (previously 190/290), Thayer’s capstone undergraduate design course sequence: a dehumidification system for spacecraft cabins.
“The challenge in spacecraft is that when you exhale, exercise, and perspire you put humidity into the cabin air and there’s nowhere for it to go. The only thing you can do is recondense it and recycle it. But condensing water in microgravity is really hard,” explains Fagin. “A commercial condensing unit you use in your house cools the airstream and then lets the water rain out into a collection dish. But in space there’s no gravity and there’s no such thing as rain, so we have to come up with some other way to grab the water and pull it out of the airstream. On the space shuttle and international space station they have a system for that, but it’s heavy and clunky and has a large centrifuge to simulate the effects of gravity. Our project, which was inspired by our sponsor at the Glenn Research Center, does away with all moving components. It uses a block of specially treated porous graphite that works like a sponge, sucking the moisture out of the air without the need for a centrifuge.”
Designed for use in zero gravity, the dehumidification system worked as intended. “We collected great data from our prototype. We were able to show that our porous media condensing heat exchanger functions well under a variety of gravitational environments,” says Currey, who interned at NASA’s Glenn Research Center in Cleveland in 2010.
The team is moving on but hopes that NASA will take over the project. “We are going to pass all of our data from the flight on to Glenn Research Center,” says Currey. “There are still a few challenges that need to be overcome. While in Houston, our team had a chance to speak with members of mission control charged with overseeing the current water system and dehumidifier, the Common Cabin Air Assembly, aboard the space station. They were interested in our idea but concerned about how they could keep it clean. This problem had crossed our minds during ENGS 89/90 but was placed on the back burner. Once this issue is resolved, I think the porous media condensing heat exchanger could be put to great use in orbit.”