April 2004

New Jersey Institute of Technology

NJIT grad student and professor take ride of their lives in vomit comet

Actually, doctoral candidate Alexandre Ermoline, North Arlington, NJ and NJIT Assistant Research Professor Mirko Schoenitz , PhD, Princeton, NJ, took four rides over four days aboard a KC-135 aircraft operated by the National Aeronautics and Space Administration (NASA). NASA operates the craft at the Lyndon B. Johnson Space Center in Houston which advances research in microgravity.

"Moving without gravity is an unusual sensation," recently recalled Schoenitz. "I've heard people describe it as falling from a height. But to me, that wasn't what it felt like at all. I had the impression that all directions were equal and I could move anywhere I wanted to go. I would definitely do it again."

Edward Dreizin, PhD, Yardley, Pa, associate professor of mechanical engineering at NJIT, was the principal investigator of the project. Vern Hoffman, PhD, Hamilton, NJ, a research engineer at NJIT, also participated.

Flying parabolic arcs at altitudes ranging between 24,000 and 34,000 feet on the KC-135 affords some 25 seconds of what's often referred to as "zero gravity" or "zero G" at the top of each parabola. Riding a roller coaster provides a tamer terrestrial version of this experience. The reason it's more precise to use the term microgravity rather than zero gravity is that there's still some gravitational influence on the KC-135, though it's a minute fraction of that exerted on the surface of the Earth. But if untethered, every person and every object on the KC-135 will float. Understandably, the flying lab is also known informally as the "vomit comet."

Ermoline and Schoenitz, who are in the mechanical engineering department with Dreizin, went to such heights for the sake of science as part of a NJIT materials research program supported since 2000 by NASA. To date, the project has received $450,000 in funding.

This past winter, Dreizin and his team presented more about this research in a paper, "Experimental Technique for Studying High-Temperature Phases in Reactive Molten Metal-Based Systems," at the most recent meeting of the American Institute of Aeronautics and Astronautics (AIAA). AIAA later published the presentation (http://www.aiaa.org/research). The group presented similar research in 2000 and 2002 at two meetings of the NASA materials science group.

The researchers rode the "vomit comet" to study the chemistry of pellets several millimeters in size containing zirconium powder, zirconium oxide and zirconium nitride as they were heated with a carbon dioxide laser to temperatures in excess of 2000 degrees centigrade, or over 3600 degrees Fahrenheit. Earlier in the program, flame propagation in aerosolized materials was studied during the 2.2 seconds of microgravity that can be simulated on Earth in the drop tower at the NASA Glenn Research Center in Ohio.

While zirconium is being evaluated as an additive to improve the performance of solid rocket fuel, gaining a better understanding of zirconium-based materials heated to very high temperatures is valuable for many other applications, including the development of gas sensors, fuel cells and ultra-hard coatings.

"The key advantage of performing this research in a weightless environment is that the free -floating pellets can be precisely positioned and laser-heated without touching any other material," said Dreizen. "It is impossible to conduct these studies in normal gravity at high temperatures because the materials under investigation will react with any container and compromise the data generated."

The NJIT team, as well as their equipment, underwent extensive preflight preparation. Ermoline and Schoenitz went through training that included being subjected to conditions in a pressure chamber simulating a decompression emergency on the KC-135. Before the actual flights, which took off from Ellington Field near Houston, they were also given medication to minimize motion sickness. Airborne, in addition to weightlessness, the researchers experienced twice the pull of the Earth's gravity as the KC-135 accelerated to altitude. NASA's requirements for getting the NJIT experimental setup into the air were stringent. For example, Schoenitz said that all equipment taken aboard the KC-135 had to withstand ten times the force of terrestrial gravity, or 10 G's, in every axis for reasons of safety. NJIT had to convince the space agency that the university's equipment was exceptionally robust. That's because it had to contain a high-temperature experiment that involved operating a 125 Watt Class IV laser -- the most powerful laser ever flown on the KC-135.

Dreizin says that his team spent three years getting their apparatus ready for lab tests at the university. It took another full year of special preparation to ready the equipment for the KC-135 experiments and to pass NASA's rigorous safety review. While everyone was apprehensive as the time approached to take to the air, all turned out well. The experiments on the KC-135 were very successful, yielding new data about materials essential to technological advances on Earth and in space.

Dreizin, Ermoline, Schoenitz and Hoffmann are now preparing the results for another publication. With these experiments, their current NASA-funded microgravity research nears its conclusion. However, they're thinking about new proposals, among them more work on the microgravity materials frontier. The continuing NASA program in this area, which still has a number of university and industry projects under way, also offers the possibility of experimentation on the space shuttle and the international space station. Perhaps at some point in the future, NJIT researchers will take their search for new knowledge to even greater heights.

NJIT is a public, scientific and technological research university enrolling more than 8,800 students. The university offers bachelor's, master's and doctoral degrees to students in 80 degree programs throughout its six colleges: Newark College of Engineering, New Jersey School of Architecture, College of Science and Liberal Arts, School of Management, Albert Dorman Honors College and College of Computing Sciences. The division of continuing professional education offers adults eLearning, off campus degrees and short courses. Expertise and research initiatives include architecture and building science, applied mathematics, biomedical engineering, environmental engineering and science, information technology, manufacturing, materials, microelectronics, multimedia, telecommunications, transportation and solar physics. NJIT ranks among the top schools of U.S. News & World Report's list of national doctoral universities.






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