September 20, 2001
Whitworth Professor Receives Major Equipment
Scientists from other Eastern Washington universities and industrial laboratories have already expressed interest in using the 750-hertz, argon-fluoride laser that will be the only one of its kind in Spokane. The $115,000 instrument is funded by a National Science Foundation grant to Richard and Karen Stevens, Whitworth's dynamic husband-and-wife team of science professors in the physics and chemistry departments. Fewer than one in three of the major research instrumentation grants were funded in a highly competitive review that included proposals from top U.S. research institutions.
"There's an expectation by the National Science Foundation for something scientifically useful and significant - new knowledge - to come out of this grant," Richard Stevens says. "That says a lot about the confidence they have in Whitworth's research program."
The NSF grant is the ninth external grant in three years that Richard Stevens has received to fund his research using laser spectroscopy to examine physical phenomenon related to spacecraft propulsion. He and his Whitworth colleagues also recently launched an initiative to integrate research more fully into the undergraduate science curriculum - a push that has doubled the number of physics and pre-engineering graduates at the college since 1998. Stevens says that several current science students cited his NASA research on electric thrusters as a factor in their decision to attend Whitworth.
Stevens is among a select group, including scientists at Stanford, MIT, the University of North Carolina and several other major engineering schools, contracted under NASA's electric propulsion research program to study the new thruster technology. Despite the considerable promise electric propulsion systems have shown in NASA's Deep Space 1 mission and in several commercial satellite launches, Stevens says, much more information is needed to fully understand their performance characteristics and operating lifetimes.
Electric thrusters are 10 times more fuel-efficient than traditional chemical thrusters and may make it practical to mount longer and more distant space missions than any to date. While traditional rocket thrusters create thrust by burning chemicals such as hydrogen, electric propulsion systems function by ejecting electrically charged particles out of a thruster at extremely high speeds. These thrusters are relatively weak, but they make up for lower power by running continuously. The little bit of force they generate adds up and, over the course of a year, can increase the speed of a spacecraft by up to 300,000 mph. The downside is that the continuous operation speeds up wear and tear on key components.
Stevens' role is to study the feasibility of using a laser spectrometer to measure the rate at which these components break down. By shining a laser into the exhaust plume of a thruster and analyzing the wavelengths of light that bounce back, Stevens can immediately detect and measure the amount of a particular material present in the exhaust.
"NASA is testing a variety of different thruster configurations, but they don't want to have to wait two years or more to determine how they're performing and they don't want to interrupt 5,000-hour and 10,000-hour tests to evaluate their performance," Stevens says. "It's a serious and expensive problem. But the approach we're studying offers a quick, accurate and non-invasive solution that NASA believes shows a lot of promise."
Stevens and his students currently conduct computer simulations and modeling with the laser-measurement system, but actual experiments have taken place off site at the Pacific Northwest National Laboratories in Richland and at NASA's Glenn Research Laboratory in Cleveland, Ohio, where students were unable to participate fully. Once the new laser is installed in early spring, Stevens and his students will be able to carry out experiments at Whitworth's recently renovated Eric Johnston Science Center.
The goal, Stevens says, is to help NASA optimize electric propulsion systems for use in future missions, including those that currently are cost-prohibitive or impractical. "These thrusters are so fuel-efficient that missions like sending humans to Mars become feasible," he says.
Stevens received a bachelor of physics with highest honors from California State University, Fullerton, in 1989 and a doctorate from Rice University in 1994. He has received research grants from the National Science Foundation, the U.S. Department of Energy and NASA and has had articles published in numerous scientific journals. In addition to teaching courses in physics and other areas, Stevens serves as Whitworth's pre-engineering advisor.
Located in Spokane, Wash., Whitworth is a private, liberal arts college affiliated with the Presbyterian Church (U.S.A.). The college enrolls 2,000 students in more than 50 undergraduate and graduate programs.
Richard Stevens, assistant professor of physics, (509) 777-4508 or firstname.lastname@example.org.
Greg Orwig, director of communications, (509) 777-4580 or email@example.com.