Purdue students complete research in NASA zero-gravity flight

Purdue students in NASA's "vomit comet"
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The students, who are participating in NASA's Reduced Gravity Student Flight Opportunities Program, flew on the C-9B zero-gravity aircraft affectionately known as the "vomit comet" in June as one of six Purdue teams to fly on the airplane this year. The plane is used by the space agency to induce weightlessness for experiments and astronaut training.

"The selection process for flying in the vomit comet is very competitive, and this team is one of just 48 from universities from across the nation that were chosen to participate," said Steven Collicott, an associate professor in Purdue's School of Aeronautics and Astronautics and the team adviser. "One of the main considerations is the type of experiment the students propose to conduct during the flight. The students have to design and fabricate the experiments to meet NASA's safety regulations."

The plane flies in steep up-and-down parabolic maneuvers, producing periods of weightlessness lasting about 25 seconds during downward "parabola" or downward maneuver, giving students scant time to ready their experiments for the next parabola.

The team designed an experiment to analyze how liquid droplets impact and wick in narrow channels in a "grooved wall." Researchers need to study how fluids behave in zero gravity in order to design more efficient life-support systems that recycle water and air. The grooved wall is a structure with no moving parts that separates air from water in the recycling process.

"We need to learn more about how droplets adhere to the grooved wall and how they move within these grooves," Collicott said. "For example, does this behavior depend on droplet velocity, droplet size, the size of the grooves and so on?"

Brandon Wampler, a senior in the School of Aeronautics and Astronautics from Kentland, Ind., led the student team.

"We've been working on this experiment since the fall of '05," said Wampler, who earned his pilot's license this year. "It could be important for space missions because it will help develop a system to recycle water for drinking, cooking and other uses.

"Now that we have finished our flight, we have three months to write a report on our research findings."

The experimental hardware, which resembles a fish tank, must be built properly to make sure there are no leaks or breakage under extreme variations in pressure and gravity.

"We usually get about 30 or 40 weightless periods in each flight, and this team went up twice," Collicott said. "If you add all those periods up, you get approximately a half hour of accumulated time in weightlessness during which to complete your research. It's a unique opportunity to run an experiment in weightlessness."

The students, all of whom are undergraduates, completed their research projects while taking Collicott's "zero-gravity flight experiment" class.

The plane varies the steepness of its maneuvers, and this varying steepness produces different degrees of weightless. Most of the maneuvers reproduce the weightlessness experienced by space shuttle astronauts flying in orbit around Earth, but a few of the maneuvers reproduce the gravity on Mars and the moon.

Purdue's involvement in the program began in 1996, when students approached Collicott because he specializes in research and engineering on low gravity fluids topics.

"It was so good for our students that first year that I did it the next year and the next, and then I created an upper-level undergraduate course for students to design zero-gravity flight experiments specifically for the NASA program," Collicott said. "So it's actually part of our curriculum now. It's a wonderful team-based, hands-on multidisciplinary experience."

Collicott is one of three Purdue faculty members with vomit comet teams flying this year. The others are Ivana Hrbud, an assistant professor in the School of Aeronautics and Astronautics; Ronald Reifenberger, a professor in the Department of Physics and a member of Purdue’s Center for Sensing Science and Technology; and Arvind Raman, associate professor in the School of Mechanical Engineering. Six Purdue teams have been accepted to fly in the program this year. Collicott has three teams, Hrbud has two teams, and Reifenberger and Raman are co-advising one team. Hong Tan, an associate professor in the School of Electrical and Computer Engineering, has taken a Purdue team on a research flight in the past.

Hrbud advised teams that flew in March and April. The April team conducted an experiment that studied "propellant management devices as fuel systems."

"It was a wonderful opportunity for the students to work as a team because they must design the experiment, write the proposal and then conduct the experiment in low-gravity conditions," said Hrbud. "These types of skills, in addition to what students learn in the classroom, will give them an extra edge when they enter the professional world."

The March team conducted an experiment that focused on the mathematical modeling of "slosh effects in diaphragm propellant fuel tanks."

"Our experiment had never been accomplished, and it took us three years to prepare for the flight," said Brad Crosson, an aeronautics and astronautics engineering student from Roselle, Ill., who was a member of Hrbud's team that flew in March. "We collected some very interesting data and are working on our report now."

Learning more about the behavior of fluids in fuel tanks is important because sloshing fuel can cause satellites to lose control. The team's experiment measured the movement of liquid fuel inside "diaphragm propellant tanks," which are used on satellites and spacecraft. The experiment was designed to create reliable mathematical modeling for measuring the sloshing effect of fuel with the overall aim of improving efficiency and cost savings for space-related industries.

The Reifenberger-Raman team will fly in mid-August and research ways to test and monitor gas contaminants in a spacecraft and the effects of various gases on astronauts' health. Their project, "Effects of microgravity on microcantilever-based sensing in gaseous and liquid environments," is being studied at Purdue under the guidance of the NASA-funded Institute for Nanoelectronics and Computing.

Purdue recently passed a milestone, when the 100th student flew on the airplane. Since 1996, 32 student teams have flown in the program, including 21 advised by Collicott. To date, 128 Purdue undergraduates have flown, spending more than 27 hours in zero-gravity, or the equivalent of 16 space shuttle orbits around the Earth, 57 minutes on the moon or one hour and 15 minutes on Mars. During those flights students operated 32 experiments.

The research projects help to prepare students for engineering jobs by teaching them to design and build experiments in teams with different students specializing in specific aspects of the experiment.

"This is organized just like NASA teams that design and build spacecraft," said Collicott, who teaches the course at his Purdue University Aerospace Sciences Laboratory. "The course typically attracts students who have ambitions to be astronauts. I usually choose the leader for each team, and this student is responsible for the entire proposal. It's a weighty position. It demands someone who is bright, dependable and writes well."

The experience provides students with an advantage in the job market.

"A hiring supervisor might have a stack of a hundred resumes for one job opening," Collicott said. "This type of experience helps our students stand out. It shows they have worked in a complex aerospace program. They are aware of both leadership and teamwork skills. If students are headed for graduate school, this is great research experience. If they are headed for industry, they have been introduced to concepts of manufacturability and design, and they've been introduced to issues of scheduling of fabrication."

Expenses for each team total about $6,000 and are paid for with industry contributions, university funding and by the students themselves.

"Our biggest expenses are not equipment, but expenses related to traveling to Houston for a week to 10 days," Collicott said.

The projects also include a component for outreach to motivate and inspire schoolchildren from kindergarten through 12th grade.

"Our students have visited hundreds of schools over the years," Collicott said. "They love to go back to their junior high and high schools and give talks."

Writers: Cynthia Sequin, (765) 494-4192, csequin@purdue.edu

Emil Venere, (765) 494-4709; evenere@purdue.edu

Elizabeth Gardner, (765) 494-2081, ekgardner@purdue.edu

Sources: Julie Burt, NASA media contact, (281) 244-1334, Julie.burt-1@nasa.gov

Steven Collicott, (765) 494-2339, collicot@purdue.edu

Brandon Wampler, bwampler@purdue.edu

Purdue News Service: (765) 494-2096; purduenews@purdue.edu

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