'Discovery launch pad was flawed from the start'

The Apollo-era launch pad used to shoot space shuttle Discovery into orbit two weeks ago may have been flawed from the day it was built, and will need weeks if not months of work to fix all the liftoff damage, NASA has said.

About 5,300 bricks flew off the pad during Discovery's launch on May 31, exposing a thick concrete wall underneath. The pad was built for the Apollo moon shots, and it looks as though the bricks did not adhere properly to the wall of the flame trench when they were installed in the 1960s, said LeRoy Cain on Thursday, chairman of the mission management team.

While the flyaway bricks posed no danger to Discovery at liftoff engineers have verified that's a physical impossibility - NASA wants to fix the flame trench so it does not get worse. Cain said he's confident it will be repaired in time for the next shuttle flight in October.

In orbit, Discovery's seven astronauts enjoyed a relaxed day off after their demanding construction work at the international space station. They left the orbiting complex bigger and more robust, with a new billion-dollar Japanese lab and a fully functional toilet, among other things.

Late Thursday afternoon, engineers finished scrutinising all the wing and nose images collected by the shuttle crew on Wednesday with a 30-meter laser-tipped inspection boom.

"Looks like you have a clean orbiter," Mission Control radioed. Touchdown is set for Saturday.

The thermal survey - an exhaustive search for damage was conducted later than usual because the astronauts had to wait until they got to the space station to retrieve their inspection pole. There wasn't enough room aboard Discovery for the pole at liftoff because of the giant Kibo lab.