This article is from the source 'bbc' and was first published or seen on . It will not be checked again for changes.

You can find the current article at its original source at http://news.bbc.co.uk/go/rss/-/1/hi/sci/tech/8054857.stm

The article has changed 5 times. There is an RSS feed of changes available.

Version 2 Version 3
Brute force helps Hubble renewal Brute force helps Hubble renewal
(29 minutes later)
Equipment problems have bedevilled the penultimate spacewalk to repair the ageing Hubble telescope. Equipment problems bedevilled the penultimate spacewalk to repair the ageing Hubble telescope.
Two astronauts took eight hours to resurrect a spectrograph used to study black holes, which was disabled by a power failure five years ago. Two astronauts took eight hours to resurrect a spectrograph which is used to study the chemistry of astronomical objects and failed five years ago.
Work ran over by 90 minutes due to a tool running low on battery power and a particularly awkward bolt securing a handrail that needed to be removed.Work ran over by 90 minutes due to a tool running low on battery power and a particularly awkward bolt securing a handrail that needed to be removed.
A strong yanking action loosened it and early tests show the repair a success. A strong yanking action loosened it and tests showed the repair was a success.
Suspended outside the shuttle Atlantis more than 500km above Earth, the astronauts were delayed by a handrail blocking a cover held by 111 tiny screws that had to be opened. Suspended outside the shuttle Atlantis more than 500km above Earth, the astronauts were delayed by a handrail blocking a cover held by 111 tiny screws that had to be undone.
Within lay the flawed wiring of the Space Telescope Imaging Spectrograph (STIS) - when working it splits light into its component parts. Within lay the flawed wiring of the Space Telescope Imaging Spectrograph (STIS). When working, it splits light into its component colours, to reveal information about the chemical content, temperature and motion of planets, comets, stars, interstellar gas and galaxies.
After several failed attempts to unscrew the bolt on the handrail they ended up tearing it off with brute force. After several failed attempts to unscrew the bolt on the handrail, the spacewalkers ended up tearing it off with brute force.
The astronauts, Michael Massimino and Michael Good, taped the pieces so they would not fly off into space where they could become potentially lethal projectiles whizzing about in orbit around the world. The astronauts, Michael Massimino and Michael Good, taped the pieces so they would not fly off into space where they could become potentially lethal projectiles whizzing about in orbit.
But there were further delays when a specialist tool designed to remove the screws of the cover plate had to be returned to the shuttle Atlantis to have its worn out batteries replaced with fully charged ones. But there were further delays when a specialised tool designed to remove the screws of the cover plate had to be returned to the shuttle Atlantis to have its worn out batteries replaced with fully charged ones.
Daily spacewalksDaily spacewalks
The astronauts upgrading the Hubble Space Telescope have now made four spacewalks in as many days.The astronauts upgrading the Hubble Space Telescope have now made four spacewalks in as many days.
They have overhauled Hubble's broken main camera, installed new a Cosmic Origins Spectrograph (COS). On Saturday, they installed the new Cosmic Origins Spectrograph (COS).
It works in a similar way to STIS. By dissecting light, it will enable Hubble to gain new insights into the large-scale structure of the Universe, and determine how galaxies, stars and planets formed and evolved.
HUBBLE SPACE TELESCOPE Named after the great US astronomer Edwin HubbleLaunched in 1990 into a 600km-high circular orbit Equipped with a 2.4m primary mirror and five instrumentsLength: 15.9m; diameter: 4.2m; Mass: 11,110kg In pictures: The best of HubbleHUBBLE SPACE TELESCOPE Named after the great US astronomer Edwin HubbleLaunched in 1990 into a 600km-high circular orbit Equipped with a 2.4m primary mirror and five instrumentsLength: 15.9m; diameter: 4.2m; Mass: 11,110kg In pictures: The best of Hubble
The astronauts were able to restore the camera's wide field channel, with which most of its astronomical observations are made. The astronauts also restored function to the Advanced Camera for Surveys - a workhorse instrument that took the telescope's deepest shot of the cosmos, the so-called Hubble Ultra Deep Field.
But the repairs failed to recover the ACS high resolution channel, which may now be down for good - despite hopes it could be retrieved another way. An electronics failure had closed down two of its three channels, but the Atlantis spacewalkers were able to revive one of them - the camera's wide field channel, with which most of its astronomical observations are made.
On Friday, the astronauts struggled to complete a critical repair to the telescope, refurbishing a pair of gyroscopes into the telescope after a new set refused to go in. On Friday, the astronauts replaced the telescope's gyroscopes, which are used to point the observatory at targets in the sky.
Sunday's spacewalk team also endured the eight hour mission of the second day when Michael Massimino felt, at times, "like I was wrestling a bear" completing the tricky task to replace and correct the telescope's gyroscopes. On Thursday, the telescope's Wide Field and Planetary Camera 2 was replaced with the Wide Field Camera 3, giving the telescope an even deeper view into space - and therefore further back in cosmic time.
Previously, only three of the six gyroscopes worked, now Hubble has four brand new sets and two refurbished ones. Only two are needed to orient the telescope properly. In addition, a data processing unit that failed last year was replaced.
On Thursday, the telescope's Wide Field Planetary Camera 2 was replaced with the Wide Field Camera 3, giving the telescope an even deeper view into space - and back into the history of time.
A data processing unit that failed in 2008 was also replaced.
The fifth and final spacewalk is set for Monday and the telescope will be released from the cargo bay of the Atlantis shuttle on Tuesday.The fifth and final spacewalk is set for Monday and the telescope will be released from the cargo bay of the Atlantis shuttle on Tuesday.