Two Down, Three To Go: "JOHNSON SPACE CENTER -- It took them seven hours, 56 minutes, but astronauts Mike Good and' Mike Massimino kept the final servicing mission to the Hubble Space Telescope on track with their first spacewalk together.
The second EVA of the mission ran long because of the trouble the spacewalkers encountered replacing the telescope's six gyros' (see previous post). Before closing the doors on that worksite, Massimino managed to connect some power cables as a get-ahead task for EVA No. 3 tomorrow. This video shot with his helmet camera shows just how tight the workspace was.
Once the gyros were installed, the EVA team and' controllers at' mission control here decided to press on to replace the first of two battery modules before returning to the airlock. That required Massimino to replenish the oxygen' in his spacesuit, but the work itself' went fairly smoothly. Weighing 460 pounds on the ground, each module contains three nickel hydrogen batteries that store electricity generated by the telescope's solar arrays' for use in orbital darkness.
The batteries haven't' been replaced since the telescope was launched 19 years ago, and have worked' well even though they were designed for five-year service life.
The second EVA ran so long that mission managers here decided to give the crew an extra hour before going to sleep to finish the work necessary to get ready for the third spacewalk of the mission tomorrow. They will also get' to sleep an extra' hour - until about 5:30 a.m. EDT -- on Saturday. Spacewalkers John Grunsfeld and Drew Feustel are scheduled to spend the day removing the Corrective Optics Space Telescope Axial Replacement, which fixed a flaw accidentally ground into the telescope's main light-gathering mirror, and then installing the' Cosmic Origins Spectrograph in its place.
They will also attempt to repair the Advanced Camera for Surveys, which has four electronics cards that need to be replaced. Spacewalks also are' scheduled on Sunday and Monday.
(Via On Space.)