Shuttle Atlantis astronauts have completed the fifth and final spacewalk to repair the Hubble Space Telescope.

阿特兰蒂斯号飞船航天员完成第五次太空行走，完成了对哈勃望远镜的最终修复。

John Grunsfeld and Drew Feustel renewed the observatory's batteries which enable it to keep operating when its solar panels are in shadow.

They also replaced a fine-guidance sensor¹ that helps keep the telescope's gaze（凝视，注视） precisely² fixed³ on image targets.

In addition, the spacewalking pair fitted three thermal⁴（热量的） blankets protecting Hubble's electronics.

Monday's spacewalk lasted seven hours and two minutes.

The servicing mission has been a great success so far.

Difficult to budge⁵ bolts and problematic tools have slowed the spacewalkers on occasions but overall they have been delighted with their progress through the list of planned refurbishments.

"This is a really tremendous adventure that we've been on, a very challenging mission. Hubble isn't just a satellite - it's about humanity's quest for knowledge," said Grunsfeld.

"A tour de force of tools and human ingenuity（智巧，创造力）. On this mission in particular, the only way of finding the limits of the possible is by going beyond them into the impossible.

"On this mission, we tried some things that some people said were impossible…. We've achieved that, and we wish Hubble the very best."

Hubble will be released from the orbiter's cargo⁶ bay on Tuesday, with the repairs and upgrades that the mission has accomplished⁷ promising⁸ at least five more years of observations.

Space shuttle Atlantis is scheduled to return to Earth on Friday.