UK's Kathy Sienko testing the undamaged truss; Jennifer Ditz at the helm;
Sam Dick, WKYT-TV, interviewing Kathy between parabolas
Abstract
A team of Engineering students from the University of Kentucky and the University of Houston participated in the 1997 NASA Reduced Gravity Student Flight Opportunities Program. Their experiment verified damage detection capabilities for spacecraft truss structures in a zero-gravity environment. The results of this work could, in the future, contribute significantly to the success of our space station.
The experiment, called Z-GraDE (Zero-Gravity Damage Evaluation), involved a series of vibration tests of undamaged and damaged truss structures ``floating'' in a zero-gravity environment. Zero-gravity testing is required to more closely simulate actual in-space conditions, since land-based testing can only provide an approximation of the behavior of these structures in space. A number of successful experiments have been completed in ground laboratory environments to verify methods for the non-destructive evaluation of damaged trusses, but this effort was the first to attempt to verify truss damage detection capabilities in a zero-gravity environment.
While at Johnson Space Center in Houston in April 1997, two UK students conducted vibration tests of undamaged and damaged truss structures while aboard a NASA KC-135 jet. This is the same plane used to train astronauts and for filming the movie, ``Apollo 13''. The four-engine KC-135 can achieve a near ``weightless'' environment by following a series of parabolic flight trajectories. As the plane flies over the top of each parabolic arc (up to 40 times in a single flight), it provides 25 seconds of zero-gravity.
The UK students chosen to train and fly were Kathleen Sienko, Jennifer Ditz and Shawn Smith (alternate). Kathleen was a junior majoring in Materials Science Engineering and is from Maine, New York. Jennifer, who is from Fairfield, Ohio, was a senior in Mechanical Engineering. Shawn, a senior in Mechanical Engineering from Pippa Passes, Kentucky, was the alternate member of the flight crew and a member of the ground crew. The ground crew also included Aaron Smith, a senior in Mechanical Engineering from Lakeville, Minnesota, Jen Eckert, a junior in Mechanical Engineering from Fairfield, Ohio, and James Jackson, a sophomore in Mechanical Engineering from Charleston, West Virginia.
Sponsors for the project included PCB Piezotronics, Depew, NY; the Kentucky Space Grant Consortium; McDonnell Douglas Aerospace, Houston, TX; UK College of Engineering; Link-Belt Construction Equipment, Lexington, KY; David Watt, UK Vice-President for Research; Louis Swift, UK Dean of Undergraduate Studies; TEAC, America, Montebello, CA; and the University of Houston College of Engineering.
For more information on the Z-GraDE project, contact Dr. Suzanne Weaver Smith at (606) 257-4584, or by e-mail at ssmith@engr.uky.edu, or by mail at 467 Anderson Hall, Lexington KY 40506-0046.