Protecting the space shuttle from meteoroids and orbital debris

Abstract

Because the Shuttle Orbiter was designed and built before the current understanding of the orbital debris environment was developed some of its components are at significant risk to damage from this hazard. The Shuttle Orbiter has been struck many times by small meteoroids and orbital debris (M/OD) but it has yet to be severely damaged. Potential damage can range from damage that does not effect a mission but" increases refurbishment costs; to damage that would force the crew to abort a mission; to damage that would result in significant refurbishment cost and down time for the Orbiter; to damage that would result in loss of life or the vehicle. Astronauts conducting extravehicular activities are also at risk from meteoroids and orbital debris. As a result of the increased awareness of the risk to the Orbiter from orbital debris the Space Shuttle program instituted several modifications and procedures to better understand the problem and to minimize its associated risk. These included pre-flight M/OD risk assessments prior to every Space Shuttle mission; attitude timeline adjustments if needed to ameliorate higher than acceptable risk; a program of post flight M/OD damage assessments; an engineering reassessment of the vulnerability of key Orbiter subsystems to orbital debris damage; and the initiation of modifications to mitigate the vulnerability of key Orbiter subsystems to M/OD damage. In addition NASA commissioned the National Research Council to conduct an independent review of the Space Shuttle Program's strategy for assessing and mitigating the threat posed by the meteoroid or orbital debris environment.