Enhancing Quality Assurance using Virtual Design Engineering: Case Study of Space Shuttle Challenger

International Journal of Aviation, Aeronautics, and Aerospace Volume 2 Issue 4 Article 6 10-28-2015 Enhancing Quality Assurance using Virtual Design Engineering: Case Study of Space Shuttle Challenger Kouroush Jenab Embry-Riddle Aeronautical University, Scot Paterson Embry-Riddle Aeronautical University, Follow this and additional works at: https://commons.erau.edu/ijaaa Part of the Aerospace Engineering Commons, Atmospheric Sciences Commons, and the Meteorology Commons Scholarly Commons Citation Jenab, K., & Paterson, S. (2015). Enhancing Quality Assurance using Virtual Design Engineering: Case Study of Space Shuttle Challenger. International Journal of Aviation, Aeronautics, and Aerospace, 2(4). https://doi.org/10.15394/ijaaa.2015.1071 This Article is brought to you for free and open access by the Journals at Scholarly Commons. It has been accepted for inclusion in International Journal of Aviation, Aeronautics, and Aerospace by an authorized administrator of Scholarly Commons. For more information, please contact , . Enhancing Quality Assurance using Virtual Design Engineering: Case Study of Space Shuttle Challenger Cover Page Footnote The authors would like to express their sincere appreciation to anonymous referees for their valuable comments which enhanced the quality of this paper. This article is available in International Journal of Aviation, Aeronautics, and Aerospace: https://commons.erau.edu/ ijaaa/vol2/iss4/6 Jenab and Paterson: Enhancing Quality Assurance using Virtual Design Engineering Many Quality Assurance (QA) techniques require the QA team to predict a particular hazard before it can be categorized and managed (Rausand, 2005). On top of this, standard QA techniques generally fail to consider multiple or complex hazard interactions. These interactions lead to situations where multiple minor hazards could interact to create a catastrophic outcome (Rausand, 2005). Virtual Design Engineering allows for the exploration of a design and its potential failure modes before it has even been built. Expanding upon this capability, QA engineers can utilize the massive computing power available today to stimulate and simulate various failure modes and their interactions. The virtual environment would allow the engineer to study extremely difficult situations with respect to quality and hazards by virtually testing various solutions in a cost effective manner. For example, a QA engineer could use the known physical characteristics of the materials in the Space Shuttle Solid Rocket Booster (SRB), apply extreme environmental factors such as low temperature, and extreme wind shear forces, and simulate the pressurization of the system. By utilizing Virtual Design Engineering processes, the engineer could pause time and virtually explore the entirety of the system, discovering any potential hazards and quality issues. The SRB as used on the Challenger were comprised of 11 individual sections approximately 12 feet in diameter that were fitted together using tang-andclevis joints secured by 177 steel pins as demonstrated in Figure 1 from the Rogers Commission Report (Rogers Commission, 1986). Sections of the SRB are joined together at the factory to reduce the number of joints to be fitted by engineers at the assembly building to four, known as “field joints” (Rogers Commission, 1986). The Rubber O-Rings are coated with a Zinc Chromate Putty to act as a kind of insulation between the hot gasses and the O-Rings themselves, however this putty was also integral in the “activation and seal” of the O-Rings (Rogers Commission, 1986). When the putty was pressed outward it would act to force the O-Ring into the gap between the Tang and Clevis joint in a process called “pressure activation of the O-Ring seal” (Rogers Commission, 1986). Should this pressure activation be delayed, for example by cold temperatures, the gap could be opened considerably and there would be a high probability that the hot gasses would escape past the O-Ring and “damage or destroy” the seals (Rogers Commission, 1986). Many tests of the O-Rings have shown resiliency degradation due to “low to moderate temperatures”, and thus they were unable to achieve the proper activation and seal in the required time of 600ms (Rogers Commission, 1986). Published by Scholarly Commons, 2015 1 International Journal of Aviation, Aeronautics, and Aerospace, Vol. 2 [2015], Iss. 4, Art. 6 Figure 1. Tang-and-clevis connection (from Jenab & Pineau, 2015) Eventual failure of the joint within the SRB was due to a combination of these complex factors, but of particular importance were the inadequate O-Ring seal and the interaction of the eventual escaping hot gasses with the aerodynamic forces of the spacecraft as it ascended through the atmosphere (NASA, 1986). As the space shuttle ascended it encountered wind shear effects matching the largest values experienced on previous flights, which created a relatively large fluctuation of forces on the vehicle and potentially magnified any existing defects (NASA, 1986). At 58.788 seconds into the flight, the first flame was captured on video, which grew into a “continuous, well-defined plume” shortly thereafter (NASA, 1986). As this flame grew “it was deflected rearward by the aerodynamic slipstream and circumferentially by the protruding structure of the upper ring attaching the booster to the External Tank” (NASA, 1986). Within only a matter of seconds this flame, directed by the complex aerodynamic forces of ascent, impacted and breached the external fuel tank leading to the catastrophic loss of the spacecraft and crew (NASA, 1986). Using a Virtual Reality QA model would help the QA engineers detect the interactions of known hazards during the extreme https://commons.erau.edu/ijaaa/vol2/iss4/6 DOI: https://doi.org/10.15394/ijaaa.2015.1071 2 Jenab and Paterson: Enhancing Quality Assurance using Virtual Design Engineering environmental conditions experienced on launch morning, giving them a high risk level and forcing their mitigation prior to any actual failure with the launch vehicle. Literature Review Virtual Reality (VR), also known as Virtual Environment (VE), refers to an “artificial reality” created utilizing computers to give the user a “first-person, interactive view into the simulated (hypothetical) world that has been created” (Lerner & Lerner, 2013). Virtual Manufacturing (VM) takes this one step farther within the manufacturing sector, in that a computer system is utilized to generate information related to the “structure, status, and behavior” of a particular system within a virtual environment (Mujber et al., 2004). The end goal with VM is to manufacture the system within the computer simulation environment and discover manufacturing and assembly difficulties prior to actually physically building the system. The natural extension of this is Virtual Prototyping (VP), which is taking the virtually manufactured system and applying a real world envi (...truncated)