Nasa engineers spot a piece of debris striking the shuttle during launch. In space, the crew continue their mission, unaware of the concerns, but the clock is ticking to re-entry.
Nasa engineers analyse film footage of a piece of debris striking the shuttle Columbia 81 seconds after launch. What no-one yet knows is whether any serious damage has been done to the vehicle or the tiles which protect the vehicle against the intense heat of re-entry. But calls for photographs to be taken of the shuttle using satellites go unheeded.
Meanwhile, in space, the crew continue their mission, unaware of any concerns inside Nasa.
