Alistair Jackson reports: "Colombia placed the world's largest X-ray telescope into orbit"

The four-day mission, led by Air Force Colonel Eileen Collins, the first woman to command one of Nasa's space shuttles, was one of the shortest shuttle missions ever.

Shortly after the shuttle rolled to a halt at 0320 GMT, Col Collins called out to mission control: "Houston, Columbia wheels stopped."

Columbia had to be modified to carry Chandra

The reply was: "Welcome home. Eileen, you and the crew (have done) just an outstanding job."

Among the tasks completed by the mission was the launch of the gigantic Chandra X-ray telescope.

This was the largest payload every carried into space onboard a shuttle.

Chandra will spend the next five years in orbit gathering information on some of the most violent explosions and energetic objects in the Universe - black holes, supernovae and quasars.

But the mission was not without problems. The first launch was delayed by a false alarm, and a second attempt by a series of thunderstorms over Florida.

The giant $1.5bn telescope was released seven hours after lift-off

The shuttle finally took off on the third attempt, although a minor malfunction in Columbia's main engines meant the spacecraft burnt its supply of hydrogen fuel too fast and ended up 11 km short of its intended orbit.

However, the orbit was high enough to carry out the launch of Chandra.

The Chandra telescope has been waiting over a year for a shuttle flight into orbit and scientists will have to wait a little longer as the complex instrument is carefully activated.