DSMC simulations in support of the Columbia Shuttle Orbiter accident investigation.
- NASA Johnson Space Center, Houston, TX
Three-dimensional Direct Simulation Monte Carlo simulations of Columbia Shuttle Orbiter flight STS-107 are presented. The aim of this work is to determine the aerodynamic and heating behavior of the Orbiter during aerobraking maneuvers and to provide piecewise integration of key scenario events to assess the plausibility of the candidate failure scenarios. The flight of the Orbiter is examined at two altitudes: 350-kft and 300-kft. The flowfield around the Orbiter and the heat transfer to it are calculated for the undamaged configuration. The flow inside the wing for an assumed damage to the leading edge in the form of a 10- inch hole is studied. The tragic loss of the Space Shuttle Columbia and her seven-member crew was followed by an investigation that lasted almost 7 months covering numerous failure scenarios. Due to the lack of physical data about flight STS-107 (especially in the high altitude part of it), numerical simulations were employed to help with the interpretation of the forensic evidence and the evaluation of the plausibility of the candidate scenarios. The conclusion of the investigation was that the physical cause of the loss of Columbia and its crew was a breach in the Thermal Protection System. To protect the aluminum structure of the Orbiter during re-entry, the Orbiter is covered with various materials collectively referred to as the Thermal Protection System. The three major components of the system are various types of heat-resistant tiles, blankets, and the Reinforced Carbon-Carbon (RCC) panels. The RCC panels are layers of graphite molded to the desired shape at very high temperatures. RCC is used for the Orbiter nose cap, chin panel, forward external tank attachment point, and wing leading edge panels and T-seals. RCC is a material capable of withstanding temperatures up to 2,000 K. Each wing leading edge consists of 22 RCC panels numbered from 1 to 22 moving outward on each wing. Because the shape of the wing changes from inboard to outboard, each panel is unique. A small space between the upper carrier panel and the RCC panel allows air pressure to equalize behind the RCC panels during ascent and re-entry. The total area of these vents on the wing is approximately 66 in. Most other areas of the Orbiter exposed to medium and high heating are protected by the tiles, which are made of a silicon-based material and can withstand temperatures up to 1,500 K. Finally, regions of the Orbiter that experience only moderate heating are protected by blankets capable of withstanding either 650K or 1,000 K.
- Research Organization:
- Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 957197
- Report Number(s):
- SAND2004-2627C; TRN: US201007%%613
- Resource Relation:
- Conference: Proposed for presentation at the 37th AIAA Thermophysics Conference held June 28 - July 1, 2004 in Portland, OR.
- Country of Publication:
- United States
- Language:
- English
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