‘Vomit Comet’ lets students defy gravity

This past summer at the Johnson Space Center in Houston, four University of Miami sophomores rode aboard NASA’s C-9 reduced gravity aircraft, one of the world’s most sophisticated and advanced aircraft.

Not quite astronauts, but close enough.

NASA’s Reduced Gravity Student Flight Opportunities Program selects fifty undergraduate proposals out of hundreds from across the country. When students are accepted into the program, they are given the opportunity to design, build and then test their own experiments aboard the C-9 plane.

“I heard about [the program] when I was a senior in high school,” McNaught said. “I met [the rest of the team] in one of UM’s clubs and told them about it. Everybody was excited about it.”

McNaught, Dussling, Huber and Hawkings, who at the time were freshmen, were definitely excited on Jan. 6, when Joseph received an e-mail confirming their admission to the program.

After working on their proposal for two months, the program’s first all-freshmen team continued working tirelessly on their experiment until August.

“Even when we got to Houston we kept working on [the experiment] everywhere, from the plane’s hangar to the hotel breakfast room,” Hawkings said. “People looked at us weird. It was pretty funny.”

NASA provided the aircraft, fuel, crew and operation of the plane for each team, but the students had to fully fund their experiment. The Florida Space Grant Consortium donated $1,500 and Dr. Lewis Temares, dean of the College of Engineering, contributed $5,000 from the university.

The experiment, entitled “Gas and Particulate Flow in a Liquid Medium in Microgravity,” applies to waste management aboard a spacecraft and relates to rocket burning technology.

The test evaluated how air, water and solid particulates, in this case Styrofoam and air soft pellets, flow through a tube. This sort of movement is called a three-phase flow, and waste management on a spacecraft runs on a three-flow system. The team used a device called the Vortex Separator, which was donated to them by Texas A&M, to separate air and water in zero-gravity.

The test also applies to the actual craft’s rocket propulsion system, excluding the rocket boosters, because of its use of solid fuel. This solid fuel melts into a liquid during flight and, if not burned properly, some of the original solid particles could potentially damage the tip of the space shuttle’s nozzle and affect the trajectory and thrust of the craft.

“If you know the fluid velocities you can predict the flow regime that should occur in the entire system,” Dussling said.

Not only did the students have to work on their experiment, but they also had to train their bodies and minds for a zero-gravity environment.

One such training took place in NASA’s hypobaric chamber, a decompressed “cabin” simulating an altitude of 25,000 feet. The team wore oxygen masks, and once the “altitude” was reached, each had to remove their masks for five minutes and attempt to solve basic math problems, among other things.

According to McNaught, this training was not easy.

“Even though they were relatively easy questions you begin to suffer from hypoxia, which is a lack of oxygen,” he said. “It was really hard to think straight.”

After completing their training and finalizing the experiment, Dussling and McNaught conducted the experiment on Aug. 10. Huber and Hawkings went up in the aircraft the following day.

After reaching 14,000 feet, the pilot took the plane up to 35,000 feet, pulling two G’s, or twice the force of gravity, in the ascent. The pilot then put the plane into a descent at 45 degrees heading back to 14,000 feet, simulating zero gravity for 25 seconds – this is when the testing was carried out. Using an instrument that measures the G-forces, the pilot maintained the zero-G’s while the experiments were performed.

These parabolic maneuvers were carried out 30 times.

“The only thing that orients you is your eyes, because all your other senses are ‘free floating’ and you’re getting pushed off from everything,” Huber said. “I even threw my camera to Tyler at one point and it went straight for him. It was weird.”

Conducting the experiment was not an easy task either, Dussling said, even though it was simply a matter of turning the system on and off.

“When you’re turning the nozzle [“on” and “off”] your whole body turns,” Dussling said. “You have to anchor yourself and then do it.”

Even after working with NASA, most of the students plan to work with private companies after they graduate.

Ricardo Herrera may be contactedat r.herrera2@umiami.