Student calculates a cost-saving maneuver for space station

Student calculates a cost-saving maneuver for space station

BY PATRICK KURP
Special to the Rice News

In a rare fulfillment of a boyhood fantasy, Sagar Bhatt watched as the International Space Station (ISS) maneuvered in space, for the first time in history without burning any costly propellant, just as his calculations had predicted.

BHATT

”It was unbelievable. For two hours, the 450,000-pound space station did exactly what we thought it would do,” said Bhatt, a third-year graduate student in computational and applied mathematics.

For 18 months, Bhatt has worked as a fellow at The Charles Stark Draper Laboratory, collaborating with colleagues to perfect the Zero-Propellant Maneuver (ZPM). Bhatt was at Johnson Space Center Nov. 5 as the ZPM was executed successfully.

Yin Zhang, professor of computational and applied mathematics and Bhatt’s adviser, praised the hard work and ingenuity of Bhatt and others in his research group: ”He is a good student, smart and works extremely hard.”

Bhatt collaborated with Zhang and Nazareth Bedrossian of Draper Laboratory on the ZPM, which Zhang described as ”similar to the way a sailboat would tack against the wind.” Through a scheduled series of commands, the ISS was maneuvered along an optimized trajectory. The ZPM method does not require modification to the ISS flight software or the use of thrusters.

Bhatt calculated the optimized trajectory, which takes advantage of naturally occurring environmental torques to maintain the ISS gyroscopes within operational margins while performing the 90-degree reorientation.

Bhatt expects to graduate with a master’s degree in January and will go to work for Draper Laboratory.