July 27, 2011
Microgravity team conducts experiments on NASA's 'vomit comet'
Eight students lurched, tumbled and floated through an unforgettable final lab project last month. Participants in NASAs Microgravity University in Houston spent the last week of their undergraduate careers carrying out an experiment they designed for testing in a reduced-gravity environment.
This was the second consecutive year that UW undergraduates have participated in the program. Student teams design and carry out an experiment aboard an airplane that provides brief experiences of a weightless environment. Each project must address a current problem in space science. The UW students built a spinning drum to store and transfer fuel in zero gravity.
“There are a lot of different ways of transferring fuel [in space], but there are problems with each one of them,” said faculty adviser Jim Riley, a UW professor of mechanical engineering. “The students approach looks like it could have some advantages.”
One of the criteria for selection is that the idea be of possible use to NASA. The UW Microgravity Team was among about a dozen undergraduate teams chosen to participate.
“Its a competition to be accepted into the NASA program, but once you get there youre all equal,” explained team captain Alyssa Sorenson, a graduate in aeronautics & astronautics. “Once we got to Houston, it was very much: ‘You are researchers, here to do your research,” she said. “Everyone was just really nice and gracious and helpful.”
Though it was serious science, this wasnt a typical lab class. This years welcome meeting was cut short by a chance to meet and get autographs from the recently returned crew of the Endeavor space shuttle. The week-long trip included tours of full-scale replicas of the space shuttle and the International Space Station. Students also got to see actual Mission Control rooms for the shuttle, space station and historic Apollo missions, and had an opportunity to discuss career options with NASA employees.
The main event was a two-hour flight aboard the Weightless Wonder. The aircraft flies in reserved air space over the Gulf of Mexico doing a series of parabolic arcs. With each arc the plane flies up at a 45-degree angle for 90 seconds during which gravity feels twice as strong as on Earth, then drops in freefall for about 30 seconds in which passengers feel weightless. The plane does a series of 16 parabolas on the way out, and another 16 on the way back.
“Its hard to describe,” Sorenson said of the experience. “Keeping your feet underneath you is shockingly hard.”
“The first time, you dont know what to expect,” said teammate Luke Jensen. “Its like being in a dropping elevator but that feeling doesnt go away. Its something you cant experience on Earth, and its something I probably wont ever experience again.”
The flight did live up to the airplanes unsavory nickname, the vomit comet. Despite anti-nausea medication and training on breathing techniques and body positioning to prevent motion sickness, almost half the participants emptied the contents of their stomachs before landing. Sorenson was among them, but she said shed gladly do the flight again.
At the beginning of each parabola students also had to gather their composure to set the experimental parameters and flip a switch to begin recording data.
Last years team, the UW AstroDawgs, devised a system called “Rotational Damping of Slosh in Microgravity” that spins the fuel tank to reduce sloshing in reduced gravity. The force against the side of the spinning tank stabilizes the fluid, much like the force of gravity does in a fuel tank on Earth. The test results were “very successful,” Sorenson said.
This years team extended that idea, adding a system to pump fuel from the spinning tank as might be required for refueling or fuel transfer during a mission. They also built a gauge to measure how much fuel is left in the tank and tested it with video of the actual fuel level.
The students built their system over six months in the basement of the UWs mechanical engineering building.
“We built everything at least twice – everything,” Sorenson said.
Team member Scott Tandoi, a senior in mechanical engineering, designed a new tank on a 3-D computer drafting program. The Boeing Co. then built the tank in its 3-D fabrication facility, which the team also got to tour.
“Anything you can think of, they can build,” Sorenson said.
Tandoi and mechanical engineering student Sean Stoker put together much of the system as their senior-level design project, and the aeronautics students who analyzed the fluid dynamics and pumping systems received some independent study credits. But mostly the students did the extra work as a chance to gain practical experience, boost their CVs and experience an environment thats accessible to very few people who are not astronauts.
Students are responsible for all aspects of the project, including designing and building the experiment, conducting outreach activities, and raising the funds for equipment, travel, medical exams and other costs. The team also must submit a detailed technical report to NASA that describes each component and ensures it can withstand the requirements of the test flight.
“I used to work in private industry, and saw projects develop,” Riley said. “This experience is really like a real-world problem, where you have to do all the things that you would have to do on the job.”
During the year the students led educational programs. They showed their project at the College of Engineerings Discovery Days and presented a series of interactive lessons on space science to 3rd- and 5th-grade students at Seattles Maple Elementary School.
When the team finally packed up the equipment to ship in late May everything was working. But when they arrived in Houston a week later, something – maybe shipping, or a change in the air temperature and humidity – caused leakage in the seals and malfunction in the electronics.
“Similar to any science project, it came right down to the wire,” Jensen said. “We spent a few all-nighters in the hotel room fixing things up and getting it all ready to go.”
But it all ended well: “When the flight day came, everything worked as well as we could have hoped,” Jensen said.
The students got back to Seattle on a Friday evening and graduated the next day. Jensen is now traveling in South America on a Bonderman Travel Fellowship. Sorenson has a job at Boeing. About half the other students are going to graduate school and the rest have found jobs. Some team members will analyze the results and submit the findings for presentation this fall at the annual meeting of the American Institute of Aeronautics and Astronautics.
Already theres interest in forming a team for next year, Riley said. Team members will meet over the summer to begin developing a proposal to submit to NASA.
Financial support for this years team included in-kind donations from The Boeing Co. and MicroStrain, which provided a discount on the sensors. The team received additional funding from Aerojet through its parent company, GenCorp, the UWs College of Engineering, the UWs Dept. of Aeronautics & Astronautics, the UWs Dept. of Mechanical Engineering, a PACCAR endowed professorship to Riley, the Washington NASA Space Grant Consortium, and the College of Engineerings Capstone Design Fund.