View through the door of the SOFIA project

The National Aeronautics and Space Administration (NASA) and Deutsches Zentrum Fur Luft- und Raumfahrt (DLR) e.V. are working together to create a Stratospheric Observatory for Infrared Astronomy (SOFIA). One of the key elements of the modification of the Boeing 747-SP aircraft to be used is a new door system. It protects the 2.5 meter infrared telescope during flight by covering the aircraft cavity within which the telescope resides and it follows the telescopes motion to provided an unvignetted view of the sky while reducing turbulence inside the cavity. This paper describes the value added by a productive interaction of reliability engineering with the integrated product design team at NASA Ames Research Center that was responsible for design of this cavity door system. It points out key reliability improvement strategies applied to the cavity door system and offers a few principles to guide interaction of reliability engineers with a design team. It is shown, for example, that significant assistance to improve reliability is achievable with a thorough and detailed understanding of the system´s intent and an organized approach to how it might fail to carry-out its intent