5 p.m. CDT Friday, May 15, 2009
Mission Control Center, Houston, Texas
05.15.09 STATUS REPORT : STS-125-09
STS-125 MCC Status Report #09 Mission Specialists Michael Good and Mike Massimino spun up the Hubble Space Telescope with six new gyroscopes and a new battery during a 7-hour, 56-minute spacewalk. Friday’s was the eighth longest spacewalk in history.
The second of the mission’s five spacewalks began at 7:49 a.m. CDT, and by 3:15 p.m. the team had accomplished all of the planned objectives. Those included replacement of all three rate sensing units (RSUs). Each rate sensing unit contains two gyroscopes, which help the telescope point itself. The spacewalkers couldn’t get one of the three units into its slot, but they were able to install a spare that was carried on board because of the tight tolerances involved.
Good and Massimino removed one of the original battery modules from Bay 2 of the telescope and replaced it with a new unit. The module in Bay 3 is scheduled to be replaced by Mission Specialists John Grunsfeld and Andrew Feustel on Monday. The batteries provide power to the telescope when it passes into the Earth’s shadow and its solar arrays are not exposed to the sun.
Ground controllers at the Space Telescope Operations Control Center at Goddard Space Flight Center in Maryland confirmed that all six gyroscopes and the new battery passed preliminary tests.
Commander Scott Altman and Mission Specialist Megan McArthur completed a robotic arm inspection of 40 shuttle heat shield tiles that weren’t in full view during Tuesday’s inspection. Based on imagery analysis, mission managers cleared all of Atlantis’ thermal protection systems until a final pre-landing inspection on Tuesday.
The last item on today’s schedule for the crew is the review of the procedures for tomorrow’s spacewalk, the third of the mission. That spacewalk will see Grunsfeld and Feustel install a new Cosmic Origins Spectrograph and Advanced Camera for Surveys.
Because Friday's spacewalk was longer than planned, the crew will go to bed an hour later at 8:31 p.m. and awaken an hour later at 4:31 a.m. Saturday. The next status report will be issued after the start of the crew’s next day on orbit, or earlier if events warrant.