New system could provide detailed images — even of soft tissue — from a lightweight, portable device.
Three teams of MIT students are in Houston this week to carry out experiments aboard an aircraft affectionately referred to by NASA as the "weightless wonder" and by experienced MIT riders as a "vomit comet." NASA uses the modified 707 airplane, the KC-135, to study the effects of weightlessness on scientific experiments.
The MIT research projects are designed to gather data about human physiology -- sound localization, peripheral vision and heart rate -- under microgravity conditions where gravitational pull has been reduced to near zero. The students hope their findings will be useful to astronauts making long flights or living on the International Space Station.
The 11 MIT undergraduates and several hundred of their counterparts from other universities are participating in NASA's Reduced Gravity Flight Opportunities Program, half of them during March and the remainder in August. They will spend two weeks (March 15-27) in Houston where they'll get preflight training and preparation before taking a spin -- actually 40 parabolic loops -- on the aircraft.
"This is the first time in the history of the NASA program that three teams from one university have been selected to fly in the same cycle. And in my opinion, these three experiments are excellent preparation for graduate-level research," said Air Force Col. Peter Young, a senior lecturer in MIT's Department of Aeronautics and Astronautics (aero/astro) who is coordinating the projects.
The PREVIEW team (PeRiphEral Vision Experiment in Weightlessness) -- senior Tyra Rivkin and junior Stephanie Chen, both of aero/astro, and biology juniors Julie Gesch and Mark Sun -- designed and built an apparatus to test peripheral vision in microgravity and hypergravity. In microgravity conditions, blood flow to the brain increases, but scientists aren't sure how that affects peripheral vision.
The SOLO (SOund LOcalization) team -- Raffi Krikorian, a junior in computer science; and sophomores Samidh Chakrabart, of computer science and brain and cognitive sciences, Sharmila Singh of aero/astro and Boris Zbarsky of physics and mathematics -- will test our ability to determine the originating direction of sound in microgravity. This type of research could be useful in designing space habitats and developing microgravity simulations.
The NIMBLE (NonInvasive Microgravity Biomedical Life Sciences Experiment) team -- seniors Christopher Carr and Elizabeth Walker and sophomore David Pinson, all of aero/astro -- modified a flexible, wearable computer system for astronauts that serves as a biomonitoring device and multipurpose tool. During their flights, they'll monitor the heart rate by pulse and ECG measurements during both microgravity and hypergravity periods.
In addition to the extensive proposals pulled together as part of the application process and the required follow-up report, each team selected is asked to develop an outreach program for sharing their experimental results with teachers, students and the public, and to ask a professional journalist to fly with them. The NASA program is administered by the Texas Space Grant Consortium in Austin.
ROLLER COASTER RIDE
During each two- to three-hour flight over the Gulf of Mexico, the KC-135 will make repeated steep climbs and descents (parabolas), each of which creates about 25 seconds of microgravity during the drop from 35,000 to 28,000 feet. In that short time span, each experimental team will gather data, then spend the all-too-brief climbing interval preparing their equipment for the next descent.
The seats of the airplane have been removed and the walls, ceiling and floors covered with padding, making a soft tube-like interior divided into five five-foot zones allotted to teams. The students will work quickly in this small space, all the while bracing themselves -- one hand on ceiling and feet on floor -- so they don't float around during the 25-second microgravity period.
"The best analogy is really the roller coaster," said Col. Young, who rode the KC-135 10 years ago. The increased gravity on the ascent and reduced gravity on the descent can affect "even the strongest stomachs," he said. "It's a space version of sea sickness.
"Whatever you do, just don't look out the window. If you do that, you see the horizon at this odd angle" and all hope of maintaining vestibular equilibrium is lost, with an effect so strong that even the ablest mind and strongest body can't cope. Most of the group will take medication to help prevent motion sickness, "but the best thing is to have something to do, which will be no problem for these people."