CAIB PA 36-03
Date: June 27, 2003
Brown, 703-416-3532 or 281-467-8657
Columbia Accident Investigation Board
Issues Preliminary Recommendation Three:
On-Orbit/On-Station TPS Inspection and Repair Capability
ARLINGTON, VA The Columbia Accident Investigation Board today
issued its third preliminary recommendation to the National Aeronautics and Space
Administration, in advance of its appearance in the final report.
return to flight, for missions to the International Space Station (ISS,) develop
a practicable capability to inspect and effect emergency repairs to the widest
possible range of damage to the Thermal Protection System (TPS,) including
both tile and Reinforced Carbon Carbon (RCC,) taking advantage of the additional
capabilities available while in proximity to and docked at the ISS.
return to flight, for non-station missions, develop a comprehensive autonomous
(independent of station) inspection and repair capability to cover the widest
practicable range of damage scenarios.
- An on-orbit
TPS inspection should be accomplished early on all missions, using appropriate
assets and capabilities.
- The ultimate
objective should be a fully autonomous capability for all missions, to address
the possibility that an ISS mission does not achieve the necessary orbit,
fails to dock successfully, or suffers damage during or after undocking.
- At present
there is no certified on-orbit or on-station capability to inspect the orbiter
TPS for damage, or to effect repairs.
efforts, some predating STS-1, have not resulted in an operational capacity.
in imaging and inspection capabilities, materials technology, and the access
provided by the ISS have greatly improved the prospects for deploying this
An inspection of the TPS, accomplished as soon as possible after achieving orbit/rendezvous,
coupled with repair capability, would result in improved safety.
The Board is convinced of the necessity of taking all practicable steps to de-couple
foam insulation shedding from loss of crew and vehicle, including: 1) design
improvements to prevent foam shedding; 2) toughening the TPS; 3) improved TPS
inspection and repair capability.
An inspection and repair capability is fundamental to improving the ability
of the orbiter to experience TPS damage without catastrophic consequences.
This effort does not reduce the urgency or importance of aggressively reducing
all sources of potential damage to the orbiter. Only by reducing the likelihood
of damage to the orbiter, as well as developing the ability to detect and repair
damage, can the maximum safety improvement be realized.
During the STS-107 flight and investigation, the lack of repair capability was
cited repeatedly, and may have been a factor in decisions made during the STS-107
mission, including the decision not to seek images which might have assisted
in the assessment of damage resulting from the foam strike on ascent.