DURHAM, N.H.—A University of New Hampshire mechanical engineering professor is helping NASA control what is designed to be the most powerful X-ray telescope ever built.

UNH Associate Professor May-Win Thein spent her summer at the Goddard Space Flight Center in Greenbelt, Md. working on Constellation X, scheduled for launch after 2017. One proposed design is a pair of satellites working together as one giant telescope 100 times more powerful than any existing X-ray telescope. With it, scientists will be able to investigate black holes, Einstein’s Theory of General Relativity, the recycling of matter and energy, and the nature of “dark matter.”

An expert in system dynamics and control, Thein collaborated with NASA scientist Julie Thienel of Goddard’s Flight Dynamics Analysis Branch in developing a technique that overcomes signal noise, disturbance torques and other uncertainties of outer space to determine the precise distance between two satellites. That information is critical to the success of the mission.

“The Mirror Spacecraft and the Detector Spacecraft must be exactly 50 meters apart—to within sub-millimeter accuracy,” Thein explained. “The mirror receives a command from mission control to point at a specific scientific target and then the detector must slew and re-orient itself to the focal point of the optical mirror and remain there until the next command control sequence.”

Thein and Thienel developed an algorithm that could determine the precise relative distance using only directional sensors already on the spacecraft. “It’s much more cost-effective than adding extra sensors, which are very heavy, expensive, prone to failure and sometimes not even available,” said Thein. “Our research could actually be applied to almost any mission.”

Thein and Thienel have submitted their work to an international conference and are currently co-authoring a journal article. “We’re working on proposals for more collaborations now,” she said. “I’m also hoping to develop some educational programs for undergraduates, graduates and recruiting and outreach material for K-12 students.”

Thein’s research was supported by a grant from NASA’s Summer Faculty Research Opportunities program, a competitive national program which gives select faculty with limited NASA research experience a chance to engage in research at participating NASA Centers.

PHOTO CAPTION
Double Vision: The proposed Constellation X-ray Observatory will use several satellites, either two or four, as shown in this artist's conception.

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