Getting to zero gravity in Houston

After months of hard work last year, five undergraduates what is perhaps the ultimate scientific reward — weightlessness.

The Yale Drop Team — made up of Greg Mosby ’09, Michael Boyle ’10, Frances Douglas ’11, Katherine Rosenfeld ’10 and Andrew Kurzrok ’11 — teamed up with NASA at the Johnson Space Center in Houston, Texas this June to conduct plasma experiments in zero gravity aboard the C-9 aircraft known as the “Weightless Wonder.”

The group formed in early October, only a few weeks before NASA’s annual proposal deadline for student-designed experiments to be conducted under the conditions of microgravity. After weeks of brainstorming, the Yale team decided to base their project on dusty plasmas, or ionized gases with dust particles dispersed throughout. They knew NASA would be interested in this relatively new subject, team members said, and because it was so new, there were many of opportunities for research.

But just as they cleared the first obstacle — coming up with an idea — they hit another: There were no plasma experts at Yale. The students were not very familiar with the concept either. Their first few meetings as a group consisted of them “flipping through plasma textbooks, reading one sentence out loud at a time,” trying to learn as much as they could on the subject, Douglas said.

It was recently discovered that in zero gravity, a phenomenon occurs in dusty plasmas where the micro-particles create a sphere with a three-dimensional void in the center, sort of in the shape of a football, Mosby said. The Drop Team wanted to study this unexpected phenomenon in their experiment with the hopes of seeing how the dust cloud formed. The complex setup was basically composed of a vacuum chamber, which when hooked up to an RF generator and container of compressed argon gas, would create a plasma, he said.

Then came the hard part: building. The first step, Boyle said, was figuring out how vacuum chambers are built and, after a bit of scrounging around the Physics Department for materials, actually putting one together.

Mosby said the five-some spent countless hours in physics lecturer and researcher Sidney Cahn’s office as well as in the Sterling machine shop, creating parts, adjusting the setup and looking for parts to borrow. Three members of the Drop Team enrolled in a class called “Welding Technology” with the specific purpose of learning how to use the tools necessary for creating a vacuum chamber. In addition to the five hours of class time they spent per week in the machine shop, in their spring semester, Mosby said he, Rosenfeld, and Douglas often spent upwards of three hours a night in the shop, working to make their ideas into reality.

But even after the vacuum chamber was finally constructed, the team knew there wasn’t time for celebration just yet. Any experiment can work well in the lab, but it is a whole other story when it comes to succeeding in zero gravity, Cahn said.

The team arrived in Houston, Texas, only to find yet another obstacle in their way. The shipping of their supplies had been delayed, Douglas said, and while the other teams had two days to reassemble their experiments, the Yale Drop Team did not have the chance to get started until the very last minute, just as the NASA hangar — where the assembly was to take place — was closing for the last time before inspection. Short on time and with no place to work, the Yalies were forced to rent out a U-Haul and construct their plasma chamber in the back of the truck, each taking turns pulling 24 hour shifts to get it done for Monday’s inspection.

“I think the hotel thought we were building a bomb,” Douglas said, citing how there were strewn wires and little metal pieces all over the room when a maid came to give them clean towels one day. “We didn’t get any more towels the rest of the week.”

By Monday morning, though, the team had pulled it all together. Passing the strict inspections of over 20 NASA agents looking to ensure that the apparatus was safe and would be able to withstand the forces of zero gravity travel, the plasma chamber was ready for takeoff, and so were its creators, Mosby said.

In NASA’s C-9 aircraft dubbed the “Weightless Wonder,” zero gravity is achieved through the execution of about 30 parabolas over the Gulf of Mexico, Kurzrok said. NASA workers instructed the students to allow themselves to adjust to the sensation of weightlessness for the first few parabolas before attempting to conduct their experiments.

At first there was a lot of floating, flailing and cheesy grinning, Douglas said. The feeling of weightlessness, team members said, is simply indescribable. While floating in water is the closest analogy that people come up with, she said, weightlessness is much more than that.

Because there is no pressure, the lack of gravity leads to a feeling of freedom, Boyle recalled.

Overall, the testing went well, Kurzrok said. The plasma generated perfectly and the dust was subsequently dispersed into the plasma.

The only issue the team ran into was with their high-resolution science camera, Mosby said. The camera was supposed capture the dust particles and the rate at which they compressed and expanded to form the void as the plane moved through the parabolas, but it was not able to pick up the dust particles — each about only six microns in diameter — because of a lack of light, he said.

But team members said, despite the malfunction, their trip was a success. The fact that they even got the experiment to work in zero gravity, Mosby said, was a feat in itself.

Cahn said it is equally impressive how much progress the Drop Team made over the course of a year when at first, none of them had any special knowledge about plasmas.

He said the experience was a “wonderful opportunity” for the undergraduates to gain an entirely new perspective on learning. This kind of experimentation shows how difficult it is to transform an idea to an actual working piece of equipment, he said, not to mention one that passes the stringent requirements of NASA.

When it comes to NASA, “there’s no partial credit,” Cahn said.

And, of course, after the team ran their experiment, there was finally time for the students to relax. Many of the members took turns spinning in midair; Kurzrok played catch with another experimenter from Brown University, saying that even the simplest things — like a ball curving after it was thrown — could not be taken for granted in zero gravity. Boyle found a peppermint in his pocket and let it float out in front of him before gliding out to catch it in midair.

“It went by so fast,” Boyle said. Each time the aircraft reached the height of its parabolic flight, the zero gravity only lasted about 20 seconds.

“I made sure to take the time to look around, make a memory of it, of this unforgettable experience,” he said.

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