Fifth & Final Hubble Spacewalk Underway

Atlantis' Grunsfeld & Feustel at 8:45 am ET Today.

The fifth and final spacewalk by two of shuttle Atlantis' astronauts began earlier than planned this morning as they prepare to replace a battery and repair a fine pointing system to the Edwin Hubble Space Telescope.

Mission specialists John Grunsfeld and Andrew Feustel began their spacewalk at 8:20 am EDT, this morning as Atlantis sailed 350 miles over the central Pacific Ocean and into an orbital sunrise.

Their first task this morning is to replace the last set of batteries in Hubble by removing the old batteries which the observatory has used since 1990. Grunsfeld will ride the end of the robotic arm - controlled by Megan McArthur - and will open a set of doors on Hubble to remove a battery try insert. The spacewalk is ecpected to last about six hours.

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