Technically, the name of NASA's modified Boeing 707 four-engine turbojet is called the KC-135. But everyone calls it the "Vomit Comet," and for good reason.

This March, a team of Penn State engineering students will travel to the Johnson Space Center in Houston for a week to brave the Vomit Comet, hoping to conduct a physiological experiment in microgravity while trying to hold their lunch down.

The team of eight students, called Flyin' Lions, were recently chosen to participate in NASA's Reduced Gravity Student Flight Opportunities Program, administered by the Texas Space Grant Consortium. It is the first time Penn State has ever participated in the 5-year-old program.

The KC-135's flight plan looks like a roller coaster, complete with 12,000-foot drops. For the astronaut trainees or experimenters like Flyin' Lions on-board the plane, each hill, called a parabola, provides about 30 seconds of weightlessness at the top of the hill and forces about twice earth's gravity at the bottom of the hill.

The Flyin' Lions, along with other student teams from universities all around the nation, will have two flights with the Vomit Comet, each flight lasting about two hours and making 30 to 40 parabolas. Thus, in one flight, there will be a total of about 15 to 20 minutes of microgravity, during which Flyin' Lions will conduct their experiment.

"I think they're going to have a tremendous experience," said Jim Pawelczyk, assistant professor of physiology and kinesiology and one of the group's co-advisors. "You have to be organized beyond belief."

Pawelczyk was a payload specialist during the STS-90 mission on the space shuttle Columbia in 1998.

The team's other co-advisor, Sven Bilén, assistant professor of engineering design and graphics and electrical engineering, participated in the program as a graduate student at the University of Michigan.

The experiment the team will execute deals with osteoporosis and exercising in a weightless environment. When humans are in space for long periods of time, they experience accelerated osteoporosis due to the microgravity: 1.5 percent bone-loss per month, or about 15 times greater than what postmenopausal women experience. "Bone decalcification happens very, very quickly," said John Halenar (senior-electrical engineering), one of the members of Flyin' Lions.

Although exercises in space can help combat osteoporosis, current astronauts are severely limited in the number of exercises they can accomplish. Springs running from Subject Load Devices (SLD) to the astronauts' hips provide the artificial gravity needed for exercises like running on a treadmill. The artificial gravity should be equal to what the astronauts would feel on earth.

However, the springs do not work when the astronauts bend down or jump up because the force the springs provide is directly related to the vertical position of the hips. When the astronauts bend down, the spring relaxes, causing the astronauts to feel like they weigh less than what they should, and vice versa when the astronauts lift their hips from its original position.

"Right now, the current exercises are limited to where your hip level is pretty much static," said Bill Marshall (senior-mechanical engineering), student leader of team.

With an $18,000 budget donated from various groups, the team members enrolled in their own three-credit course — E G 497D (Microgravity Payload Design) — last semester to design their experiment module.

"We were looking for a meaningful experiment," Halenar said. "We looked at something that needed fixing."

What they have created is a modified SLD that actively responds to the vertical position of an astronaut exerciser's hips. When the hips go down, the SLD responds by tightening the springs attached to the hips, so the astronaut still feels full earth gravity. Vice versa occurs when the hips go up.

Their modified SLD, which they have spent about four months designing and are starting to build, consists of a motor attached to a worm-gear system and shaft that the spring is attached to, as well as optical encoders that sense the position of the hips and help adjust the spring.

The experiment module is also equipped with a force plate that measures the force exerted by the exerciser and a computer that stores all the data. While the students exercise on the plane, they will stand on the force plate with their back only a few inches off the floor, just in case gravity returns sooner than expected.

"It's an outstanding experiment," Pawelczyk said. "The issue is very real for loading people for exercise. The problem of bone are ones that may limit how long people may travel in space."

When Flyin' Lions presented their 90-page proposal to the program, the review board was impressed by the experiment. "The NASA proposal was fairly well received," Bilén said. "It was considered high applicability to NASA's goals."

Pawelczyk agreed. "They said that their proposal and application was in the stratosphere."

During each flight, two team members will fly in the Vomit Comet. Marshall and Ben Weber (senior-mechanical engineering) will fly first and Halenar, Dawn Noga (sophomore-engineering science) and Katie O'Toole, WPSX-TV writer and co-host of the public television show What's In the News, will take the second flight. O'Toole will help publicize the experiment and its results.

"Thirty percent of the proposal was an outreach plan," said Noga, adding they contacted various groups including Girl Scout troops and school classrooms. "After the flight, we're going to give our outreach program to about 10 groups now."

During each flight, one member will test out both the current passive SLD system and the experimental active system through a series of deep-knee bends and stepping exercises. After one member is done with the exercises, the other team member will repeat everything, providing two sets of data per flight.

The members will also repeat the exercises on earth, as a means of providing a control to the experiment.

The other four Flyin' Lions will provide ground support during the flights: Dana Ahmed (sophomore-electrical engineering), Robyn Berridge (sophomore-electrical engineering), Mike Moss (sophomore-electrical engineering) and Amy Seeman (sophomore-chemical engineering). Seeman is also the backup flyer.

Not only does the team hope to learn more about preventing osteoporosis in space, but it hopes its results will help bed-ridden people stricken with excessive bone loss find new ways to exercise and improve their condition.

Whatever the outcome of the group's proof-of-concept experiment, everyone agrees the experience has taught them much about the interweaving of different types of engineering.

"Mechanical directly affects electrical and vice versa," Halenar said. "It's a great application of concepts learned in class."

Both advisors agreed. "There's all these different majors, and they're learning to work together." Bilén said. "Where their strengths and interests lie, they're putting into this."

After all their hard work and passing through a gauntlet of review boards that scrutinized everything from their design to their use of human subject testing, the students also appreciate the teamwork and camaraderie that they have built.

"It's a really great opportunity," Seeman said. "It's not that common that a group of engineering students get to work together."