Space Shuttle Aerodynamics and Debris Simulations

Overview

Simulations of the Space Shuttle Launch Vehicle (SSLV) aerodynamics and debris environments have provided invaluable data to NASA's Space Shuttle Program for the past 20 years. Since the Columbia accident in 2003, these simulations have been particularly instrumental in safely completing all remaining shuttle missions, including the final Atlantis mission, which landed on July 21, 2011.

Project Details

Aerodynamic simulations completed by computational fluid dynamics (CFD) experts over the last two decades were used to refine understandings of air loads on the SSLV and on thousands of protruding parts of the External Tank, Orbiter, and solid rocket boosters. Aerodynamic analyses of several new designs for portions of the External Tank were also performed.

At the same time, wide-ranging assessments of potentially dangerous debris, including foam insulation, ice, ablators, putty repair material, tile-gap fillers, and other materials were used to establish the debris environment and the design requirements for NASA's Return to Flight effort following the Columbia accident.

These detailed debris transport analyses were used to establish rules for the maximum allowable ice-ball size that became part of the official launch commit criteria. Billions of potential ice-ball impacts were analyzed to establish detailed maps of the largest allowable ice on the External Tank.

CFD experts also provided launch-day and on-orbit mission support, including the ability to perform rapid-response debris analysis during countdown from the Mission Control Center in Houston.

Results and Impact

The development and use of high-fidelity debris transport analyses contributed greatly to the successful and safe completion of the Space Shuttle Program.

In turn, the needs of the program have driven the development of software packages and infrastructure that are now among the most powerful and useful CFD analysis tools used by NASA.

Role of High-End Computing Resources

NASA supercomputing resources have grown by a factor of 1,000 since the Space Shuttle Columbia accident. During that time, resolution of CFD simulations of the SSLV increased by a factor of 10, and the time required to produce a series of solutions representing an ascent trajectory has dropped from months to days. Supercomputers at the NASA Advanced Supercomputing facility have enabled detailed aerodynamic data and debris simulations that were impossible to obtain through either flight tests or wind tunnel tests.