Winter 1997
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Winter 1997 |
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When space shuttle astronauts blast into orbit, they rely on people like alumnus Ron Neumeyer for a proper career boost. A 1986 mechanical engineering graduate, Neumeyer is an engineer for the space shuttle main engine with Rocketdyne, a division of Boeing.
The space shuttle main engine (SSME) is a reusable rocket engine. There are three on every shuttle, and they use a mixture of liquid oxygen and liquid hydrogen for propellant. The engine can attain a maximum thrust level of 512,300 pounds, equivalent to more than 12 million horsepower. It weighs almost 7,000 pounds and measures 14 feet long by 8 feet wide. The engine, which has achieved a 100 percent flight success, is located at the bottom of the shuttle as it stands on a launch pad. It takes the shuttle from liftoff to orbit, including 6.5 minutes after the shuttle's solid rocket boosters burn out. "My area of expertise is evaluating test data and reviewing the results from that data," Neumeyer said. The data come from hot-fire tests of the actual engine and from computer simulations. The hot-fire tests take place in Mississippi on test stands that measure up to 300 feet tall. "The ground shakes, the noise is incredible and you get a real sense of how powerful the engine is," Neumeyer said. Data from those tests transfer to the Rocketdyne plant in Canoga Park, Calif., where Neumeyer works. Hot-fire tests are supplemented by computer simulations developed through software Neumeyer has written. "The computer lets us set up failure scenarios that are hard to duplicate in a real hot-fire test," he said. He cited an example of a hydrogen leak at a flange. In a hot-fire test, the leak would be difficult to enact, and it also would be dangerous. "We constantly combine the data from hot-fire tests and computer simulations to get the best engine performance we can," Neumeyer said. "Our job is pretty much done when the engine is delivered, and it's kind of scary to watch a launch because then it's really out of our hands." The Rocketdyne plant where Neumeyer works does have a launch monitoring area, and the company does receive data from launches. Probably some of the best feedback comes from astronauts who visit the plant on a periodic basis. "Astronauts come out from time to time to remind everyone there are people on the vehicles," Neumeyer said. "They have a question-and-answer period with the workers, and it's good to hear the astronauts report a smooth ride." Airplane engineering had been Neumeyer's interest area when he entered Rose-Hulman, but his focus climbed to a different orbit in a jet propulsion class taught by the late Irv Hooper. He solidified that interest upon graduation by taking a summer position with GE Aircraft Engines in Cincinnati. From there, he went to Cal Tech where his interest shifted to rocket propulsion and he earned a master's in mechanical engineering. After graduate school, Neumeyer went to work for Rocketdyne where he was assigned to the space shuttle main engine and his interest grew into a career. "One of the main rewards I receive is that I get to use most of the stuff I learned in school...thermodynamics, heat transfer...and I get to do it every day," Neumeyer said. "A lot of engineering jobs exist where they don't get to use their engineering skills." Another plus for the young engineer is found in the people he works with: "It truly is a bunch of rocket scientists; so there's a lot of bright people here." The biggest challenge Neumeyer finds is "deciding when you can definitely say yes or no based on the information you have. It's manned flight we're talking about, so safety is always a concern before cost." That's a philosophy the astronauts probably value as much as Neumeyer's engineering prowess. — by Bryan Taylor
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Neumeyer's main assignment is analyzing test data on the shuttle engine. He has been on this job for 10 years, about half the life of the space shuttle program. "Although the engine has been around for 20 years, we continue to do development testing and life studies," Neumeyer explained.