Astronauts to replace flawed Hubble camera
The emphasis will now switch from the engineering essential to keep the telescope working, to improving the astronomy it can perform.
The next stage of the repair mission, which should have started at about 4am (British time), is extremely delicate. In the third spacewalk, Story Musgrave and Jeff Hoffman have to replace the 270kg (595lbs) wide field and planetary camera.
The new camera contains a a coin-size mirror that has been ground to a prescription that should compensate for a flaw in Hubble's main 94in (238cm) mirror. In addition, the new camera will be able to 'see' well in ultra-violet light.
In theory, the camera should slide like a drawer into the telescope. But the astronauts will first have to remove the protective cover without touching the mirror itself. If, encumbered by space-suits and gloves, they do touch the mirror, they will ruin it: knocking it out of alignment and contaminating its surface.
In their spacewalk, which ended early yesterday morning, Endeavour astronauts Kathy Thornton and Tom Akers successfully equipped the Hubble telescope with two new solar panels to provide power for its operation. The astronauts spent more than six hours in space, fitting the new panels and jettisoning an old one that had buckled.
Nasa's mission controllers had ordered Ms Thornton and Mr Akers to ditch the panel, which was stuck in the open position, after Mr Musgrave and Mr Hoffman failed to roll it up and stow it in Endeavour's cargo bay during their first space walk on Sunday. Like the originals, the new panels have been supplied by the European Space Agency and built by British Aerospace.
Made of Teflon sheets covered with photovoltaic cells, the new solar arrays convert the sun's energy into electricity for scientific instruments inside the telescope. The original arrays fluttered like wings when the telescope moved in and out of darkness, interfering with the telescope's alignment.
As Ms Thornton let the panel go, shuttle commander Dick Covey slowly moved the craft away, leaving the panel to join some 7,000 pieces of debris from space missions, which will gradually be pulled towards the earth and burn up on re-entering its atmosphere.
As Ms Thornton released the panel, it caught the light from the sun, standing out against the deep blue of the Indian ocean 590km (360 miles) below as the craft orbited at 29,000km an hour.
- 1 Rihanna 'nude pictures' claims emerge on 4Chan as hacking scandal continues
- 2 Kim Kardashian 'nude photos' leaked on 4chan weeks after Jennifer Lawrence scandal
- 3 'F*ck it, I quit': KTVA reporter Charlo Greene quits live on air in spectacular fashion
- 4 What are your fingerprint words?
Rihanna 'nude pictures' claims emerge on 4Chan as hacking scandal continues
Kim Kardashian 'nude photos' leaked on 4chan weeks after Jennifer Lawrence scandal
'F*ck it, I quit': KTVA reporter Charlo Greene quits live on air in spectacular fashion
Jennifer Lawrence: Leaked 4Chan sex video branded 'fake' by users
Jennifer Lawrence 'naked sex video' will be leaked next, threatens 4Chan celebrity photo hacker
Scotland could still declare independence – even without referendum, says Alex Salmond
Scottish referendum results: Cross-party consensus collapses amid Tory-Labour spat on the 'English question'
Hilary Mantel 'should be investigated by police' over Margaret Thatcher assassination story, says Lord Bell
Scottish independence: David Cameron is becoming the 'George Bush of Britain'
Plebgate MP Andrew Mitchell called officer a 'little s**t', claim court documents 'exposing ex-Chief Whip's 'record of abusing police'
Archbishop of Canterbury admits doubts about existence of God
£16500 - £20000 Per Annum: Clearwater People Solutions Ltd: We are currently r...
£100 - £125 per day: Randstad Education Crawley: KS2 PPA Teacher currently nee...
£40000 - £45000 per annum + pension, healthcare,25 days: Ashdown Group: An est...
£28000 per annum: Ashdown Group: IT Software Application Support Analyst - Imm...