New York: Glitch in United States space shuttle Columbia's computer system and differential temperature in the left wing of the space shuttle would be the areas investigators would immediately focus to determine the cause of its break up while re-entering.

As the shuttle took off, a piece of foam insulation had broken off from a fuel tank and had hit the left wing. It was not carrying any robot arm and hence it was impossible to look under the wing for any damage.

But apparently from the video of the take off, it was concluded that not much damage has been done.

Experts now say if whatever hit the left wing damaged the tiles, which reflect heat at the time of re-entry, things could have turned sour.

At the last stages of the re-entry, the shuttle is under the control of the computers, which have a lot redundancy built into it.

PTI