Student: Christopher Wenger, Graduate Student in Aerospace Engineering, Iowa State University
Faculty Advisor: Christina L. Bloebaum
A Value Driven Approach to Capture Unintended Consequences Impacting Ares 1’s Mission Success
On November 9th 2009 NASA test launched Ares 1 –X, a prototype vehicle intended to transport astronauts into orbit on a planned mission to mars. During testing a phenomenon known as Thrust 
Oscillation occurred around 110 seconds into flight causing the vehicle to vibrate at unsafe operating conditions. Nasa responded to these events by developing the thrust oscillation mitigation team, which was tasked to research the event and design fixes to bring the structural vibrations down to a safer level. The thrust oscillation event and mitigation team costed NASA time and resources which could have possibly been avoided during the design and development phase. To solve this issue NASA contracted research to investigate the use of new system engineering approaches such as a Coupling Strength Analysis and Value Driven Design to model the physics of Thrust Oscillation and its impact on the Ares 1’s Value. Three disciplines were identified as major contributors towards the Thrust Oscillation phenomenon, these subsystems are the fluid flow in the engine, structural attributes and acoustic attributes. These subsystem interactions are modelled to determine how they impact each other and the overall system value. In the case of the Ares 1 couplings between acoustics and structures along with the impact of fluid flow onto structures were known. However, it was found that an impact of structures onto the fluid flow was overlooked. If Coupling Strength Analysis and Value Driven Design were used in early design and development, it could have saved time and money.