On February 1, 2003, the Space Shuttle Columbia broke apart during reentry resulting in loss of seven crewmembers and craft. For the next several months an extensive investigation of the accident ensued involving a nationwide team of experts from NASA, industry, and academia, spanning dozens of technical disciplines.
The Columbia Accident Investigation Board (CAIB), a group of experts assembled to conduct an investigation independent of NASA concluded in August, 2003 that the cause of the loss of Columbia and its crew was a breach in the left wing leading edge Reinforced Carbon-Carbon (RCC) thermal protection system initiated by the impact of thermal insulating foam that had separated from the orbiters external fuel tank 81 seconds into that mission's launch. During reentry, this breach allowed superheated air to penetrate behind the leading edge and erode the aluminum structure of the left wing which ultimately led to the breakup of the orbiter.
Supporting the findings of the CAIB, were numerous ballistic impact testing programs conducted to investigate and quantify the physics of External Tank Foam impact on the RCC wing leading edge material. These tests ranged from fundamental material characterization tests to full-scale Orbiter Wing Leading Edge tests. Following the accident investigation, NASA turned its focus to returning the Shuttle safely to flight. Supporting this effort are many test programs to evaluate impact threats from various debris sources during ascent that must be completed for certifying the Shuttle system safe for flight. Digital high-speed cameras were used extensively to document these tests as significant advances in recent years have nearly eliminated the use of film in many areas of testing. Researchers at the NASA Glenn Ballistic Impact Laboratory have participated in several of the impact test programs supporting the Accident Investigation and Return-to-Flight efforts.
This paper summarizes the Columbia Accident and the nearly seven month long investigation that followed. Highlights of the NASA Glenn contributions to the impact testing are presented with emphasis on the use of high speed digital photography to document theses tests.