Washington - Astronaut Mike Massimino who spent several hours on two spacewalks to repair and upgrade the Hubble Space Telescope joked Wednesday about his handyman skills back on Earth.

Asked by a reporter if his home fix-it projects ever go badly, Massimino quickly quipped "oh, no" and rolled his eyes, "You can ask my wife about that."

In one of the tensest moments of the mission, Massimino had to rip off a piece of the telescope that he could not remove because of a stripped bolt. It had to be removed in order to conduct a crucial repair to its fine guidance sensor.

Reflecting on the mission, he described it as challenging not to give up hope that they could get the task done, especially when experiencing problems with what had been an easy step in training.

The closest he had ever come to similar scenario was growing up in a close-knit Italian family in New York and watching his uncle conduct a difficult repair on his car by jamming a tool into the oil filter and just ripping it out, he joked.

His fellow crew members stressed that the challenges showed the value of manned spaceflight.

"I do think this mission highlighted our ability to work with humans in space alongside machines," commander Scott Altman said. He stressed the need of humans to service the telescope and their ability to go beyond what a robotic mission could have done.

Later Wednesday the seven-member crew received a phone call from President Barack Obama congratulating them on the mission and calling it an "incredible journey."

The space shuttle Atlantis crew conducted five straight days of spacewalks to upgrade the Hubble and keep it working through at least 2014 before releasing it back into orbit on Tuesday. They are to land at the Kennedy Space Centre in Florida on Friday.

Since its launch in 1990, Hubble has helped scientists to place the age of the universe at 13.7 billion years, learn that black holes are at the centre of most galaxies, monitor planetary formation and discover that the universe is expanding at an ever-faster pace. (dpa)