Shuttle launches will be conducted in daylight

The Discovery orbiter was due to launch in March or April on a mission to the International Space Station - the first flight since the Columbia disaster.

But Nasa says the hurricanes that have hit Florida and other south-eastern US states have delayed work schedules.

Officials running the agency's flight programme will meet in October to decide if the new date is achievable.

It would be a 22-day launch window that opens on 14 May.

Following the recommendations of the Columbia Accident Investigation Board (CAIB), the shuttles will now face much tighter restrictions on when they can fly.

Launches will be limited to certain times of the year, when lighting and other conditions are optimum.

Also, the CAIB has demanded certain alterations be made to the orbiters, particularly the external fuel tank which was the source of the foam debris that punched a hole in Columbia's left wing.

It is hoped a long inspection boom with lasers on the end, for sensing any gaps on the underside of the shuttle, will be ready in time for Discovery's flight.

The astronauts will have the ability to repair very small cracks but anything on the scale of the Columbia gash would require them to seek sanctuary in the space station until a relief shuttle could be organised to bring them back to Earth.

The CAIB recommendations must be met before the shuttles will be cleared to return to service.

If the Space Flight Leadership Council, when it meets in October, decides there is still work to be done then the first launch will be pushed back again.

After the May window, the next launch opportunity opens on 12 July.