The preliminary recommendations following the tragic loss of the space shuttle Columbia have been released on the official accident investigation site. It appears that NASA might be facing complacency, given that one possible cause of the accident, falling foam, has been an issue in previous flights.
The Columbia Accident Investigation Board (CAIB) has proposed two fundamental changes. Firstly, they suggest making Shuttle Imaging on Orbit a standard feature. This technology, although available within the US government, has been rarely used. Its purpose is to assess the orbiter’s condition after its ascent, ensuring a better understanding of potential risks.
Secondly, the CAIB recommends a comprehensive examination of Reinforced Carbon-Carbon (RCC) components, utilizing all possible forms of non-destructive testing. This recommendation comes in response to the most probable cause of the orbiter’s loss, attributed to the failure of a structural RCC component in the leading edge of the left wing.
As of now, a final verdict on the root cause of the RCC component failure has not been reached. Speculation suggests that it could be due to pre-existing damage not detected during inspection or possibly a strike from other materials, such as foam from the tank.
The leading edge components in question are highly intricate, comprising multiple layers and treatments. If the thermal protection provided by the RCC parts is breached, even in a minor way, a superheated air stream can enter the wing and damage the structural aluminum components, leading to severe consequences.