US: Astronauts wrap up 4th spacewalk to repair Hubble
18 May 2009 3:01 PM
Two spacewalking astronauts have overcome a stuck bolt .. a power tool with a dead battery and other frustrations while working to revive a long inactive science instrument inside the Hubble Space Telescope.
The outing by MIKE MASSIMINO and MIKE GOOD to recover an instrument that identifies super massive black holes was considered to be the most intricate of the five spacewalks.
The difficulties fixing the imaging spectrograph stretched their activities to more than eight hours.
The spectrograph .. which astronomers use to gather information about the chemical composition .. temperature .. and pressure motions of celestial targets .. was sidelined by a power failure in 2004.
