The mother of British-born astronaut Piers Sellers said she was "full of relief" after her son landed safely in the space shuttle Discovery.

Discovery touched down at Kennedy Space Centre yesterday in only the second shuttle flight since the 2003 Columbia disaster killed seven astronauts.

Sellers' mother, Lindsay, whose son Piers is originally from Crowborough, said: "As you can imagine, I'm enormously proud, absolutely delighted."

Mrs Sellers said she was unable to watch the landing but listened to the NASA commentary over the internet as the shuttle landed safely despite cloudy conditions.

She said: "I think I was full of relief, it was a wonderful landing.

"I was able to hear all the NASA commentary over the computer, and it was almost as good as seeing it."

Mrs Sellers, who went out to America to watch the shuttle's launch on July 4, said: "That was absolutely amazing."

Sellers carried out space walks during his second visit to the international space station.

His mother said she was "thrilled to bits" for her son when she learnt he would be walking in space during the mission.

"He has been aiming at this for most of his life, to be honest.

"To actually get the chance to get out in to space was amazing, and to get to do a space walk twice even more so."

Sellers, 51, who is married with two children, first went into space aboard Atlantis in October 2002 and holds a doctorate in biometeorology from Leeds University. He became a US citizen and joined NASA in 1996.

Yesterday's landing was the first at Kennedy in almost four years and saw six of the seven astronauts return to earth.

German astronaut Thomas Reiter was left on the space station for a half-year stay, joining two other men.

The Discovery crew, whose mission focused primarily on flight test aspects, conducted three space walks, one of them to test shuttle patching techniques, and used a 100-foot inspection crane to check the shuttle's entire thermal armour.

NASA wants to complete the station by 2010 when the three shuttles are retired to make way for a spaceship capable of carrying astronauts to the moon.