This new configuration incorporates an aeroskirt aft of the spacecraft, extending the Starliner Service Module cylindrical surface to improve the aerodynamic characteristics of the integrated launch configuration and bring loads margins back to acceptable flight levels.
"Through incredible coordination and continued innovative thinking, the collective team of NASA, Boeing and United Launch Alliance completed three wind tunnel tests in six months to investigate the aerodynamic stability of various configurations and to anchor our analytical predictions,” said Gary Wentz, ULA vice president of human and commercial services.
“Based on that information, we updated the configuration for the Atlas V Starliner integrated vehicle stack,” Wentz continued. “This configuration is unique because it combines the Atlas V launch vehicle without a payload fairing with Boeing's Starliner capsule, resulting in different aerodynamic interactions."
The aeroskirt is a metallic orthogrid structure designed to be jettisoned for improved performance. In the event that an emergency occurs during boost phase of flight, the aeroskirt has venting provisions to control over-pressurization if the Starliner's abort engines are fired.
Fabrication of the aeroskirt is scheduled to begin this month at ULA's factory in Decatur, Alabama, following completion of a Production Readiness Review.
"Our testing indicates the solution we chose will sufficiently smooth the air flow around the vehicle during ascent, ensuring crew safety and mission success," said John Mulholland, vice president and program manager of Boeing's commercial crew program.
The ULA team completed the aeroskirt preliminary design review earlier this month. The Atlas V with Starliner has a planned uncrewed flight test in 2018 with operational missions to follow.
"We look forward to our continued partnership with Boeing and NASA to ensure mission success and safety for American astronauts flying from U.S. soil on the Atlas V Starliner," said Wentz.
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