John Grunsfeld and Rick Linnehan regained the shuttle at 7:31 am, seven hours and one minute after the start of a space walk devoted to replacing one of the telescope's solar panels with smaller, better-performing ones.

Hubble's second photovoltaic generator is to be replaced during a space walk on Tuesday.

"The old array was successfully removed and stored. The new array was successfully installed. The new array properly unfolded," said NASA spokesman Rob Navias.

"Everything has gone very smoothly this morning for this first space walk. Hubble has a brand new solar array," he said.

NASA engineers at Goddard Space Center in Greenbelt, Maryland have already tested the panels, which enable the space agency to control the telescope at a distance.

The new array is doing its job, said spokeswoman Cathy Watson. Goddard will continue testing Hubble's newest equipment throughout the day.

SPACE.WIRE