Astronauts Completes Sixth Longest Spacewalk in History

NASA astronauts began their fourth spacewalk this morning to continue their efforts to repair and improve the Hubble Space Telescope. The astronauts began at 9:45 am EDT and was expected to last at least 7 hours.

Most of today's spacewalk was used to work on the telescopes, STIS or Space Telescope Imaging Spectrograph. The two spacewalkers, Mike Massimino and Mike Good also replaced a low-voltage power supply board which contained a failed power convert and because of this failed component, STIS has been in "safe mode" since August of 2004.

A delay caused by a bolt removal issue forced the spacewalkers to cancel the installation of a new protective thermal insulation panel on Hubble. Ground controllers are working various options for the fifth and final STS-125 spacewalk on Monday scheduled for 9:16 a.m.

The fourth of the five spacewalks being conducted to Hubble ended at 5:47PM today, taking 8 hours and 2 minutes to complete - the sixth longest spacewalk in U.S. history.

Due to issues with the bolt removal, the spacewalkers were unable to work on the New Outer Blanket Layer work and it has been rescheduled to take place on Monday.