Washington, Aug 27 (DPA) NASA has delayed the launch of the space shuttle Discovery by 24 hours to allow more time to review data about a suspect valve in the liquid hydrogen fuel tank, officials said Thursday.

NASA earlier this week postponed a Tuesday launch to the early hours of Friday morning after detecting a problem with the fill and drain valve. The latest plan is to proceed with the launch about midnight Friday (0400 GMT Saturday).

NASA said more time was needed to determine whether the problem lies with the valve or a gauge that was showing the valve to be open when it was supposed to be closed.

Fuel valve problems have dogged recent shuttle launches as the ageing craft and launch apparatus enters the final phase of the decades-old shuttle programme.

By late next year, NASA hopes to have completed the build-out of the orbiting International Space Station so it can retire the shuttles.