recommendations were identified as those that should be met prior to RTF. They can be found in their entirety in Chapter 11 of the Columbia Accident Investigation Board’s Report, Volume 1. The CAIB recommendations were stated as a desired end result; the report did not specifically identify how each was to be achieved.

Only two CAIB requirements are directly applicable to the viability of a space shuttle servicing mission to HST. They are the following:1

CAIB Requirement 6.4-1

For missions to the International Space Station, develop a practicable capability to inspect and effect emergency repairs to the widest possible range of damage to the Thermal Protection System, including both tile and reinforced carbon-carbon, taking advantage of the additional capabilities available when near to or docked to the International Space Station.

For non-Station missions, develop a comprehensive autonomous (independent of Station) inspection and repair capability to cover the widest possible range of damage scenarios.

Accomplish an on-orbit Thermal Protection System inspection, using appropriate assets and capabilities, early in all missions.

The ultimate objective should be a fully autonomous capability for all missions to address the possibility that an International Space Station mission fails to achieve the correct orbit, fails to dock successfully, or is damaged during or after undocking.2

CAIB Requirement 4.2-4

Require the Space Shuttle to be operated with the same degree of safety for micrometeoroid and orbital debris as the degree of safety calculated for the International Space Station. Change the micrometeoroid and orbital debris safety criteria from guidelines to requirements.

NASA is focusing the RTF effort on the ISS mission and has chartered the Return to Flight Task Group to review and evaluate the agency’s compliance with all RTF recommendations.

Additional NASA Requirements

NASA has determined that it is insufficient for RTF to simply meet the CAIB recommendations and has concluded that it should go beyond CAIB requirements to increase crew safety. Additional applicable NASA RTF activities that affect the viability of an HST mission follow:

Space Shuttle Program Action SSP-3—Contingency Shuttle Crew Support [Safe Haven]:3

NASA will evaluate the feasibility of providing contingency life support on board the International Space Station (ISS) to stranded Shuttle crewmembers until repair or rescue can be effected.


Columbia Accident Investigation Board, Report, Volume I, August, 2003, p. 174 (Requirement 6.4-1), p. 95 (Requirement 4.2-4). Available online at


The committee interprets this statement from the CAIB as a requirement for an autonomous capability (if the mission fails to rendezvous with the ISS) on an ISS mission that could also be used on a mission other than ISS.


NASA, NASA’s Implementation Plan for Space Shuttle Return to Flight and Beyond, December 3, 2004, p. 2-5. Available online at


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