STS-1 Forward RCS Oxidizer Tank Subsystem Structural Failure Assessment

The launch of the Space Shuttle Columbia on STS-1 marked the beginning of a new era in American spaceflight. It was the only crewed first flight of a launch vehicle to date, and was also the first crewed system to use large solid rockets as primary propulsion. A potential disaster was narrowly averted at liftoff when an ignition overpressure pulse swept up the Shuttle stack. The frequency of this transient shock wave exceeded pre-launch predictions, and resulted in high, alternating normal accelerations along the length of the vehicle. Among the results of this unexpected loading was failure of an oxidizer tank support strut in the orbiter’s forward reaction control system module, which could have led to loss of the mission, crew, and vehicle. This particular incident is investigated in more detail using classical structural mechanics and finite element analyses, and the results are discussed to provide additional insight.