This
story was updated at 9:20 a.m. EDT.
HOUSTON -
Atlantis astronauts kicked off an ambitious five-day marathon to fix the ailing
Hubble Space Telescope Thursday when two spacewalkers floated outside to boost
the observatory's vision.
Veteran
spacewalker John Grunsfeld and first-time spaceflyer Andrew Feustel stepped
outside Atlantis at 8:52 a.m. EDT (1252 GMT) to install a brand new
camera eye aboard Hubble and repair a vital data handling device that beams
the 19-year-old space telescope's cosmic images back to Earth.
"This is
fantastic, you're going to love it Drew," Grunsfeld told his spacewalking
partner. Grunsfeld is an astrophysicist-astronaut making his third trip to
Hubble, and his sixth career spacewalk.
The
spacewalk began a bit later than planned, but is slated to last about 6 1/2 hours and set the stage for four more
back-to-back spacewalks to make major upgrades and attempt unprecedented repairs
on the
aging Hubble. Atlantis has a four-man team that will work in pairs to
tackle the grueling spacewalk schedule.
"I'm
looking forward to seeing our old friend Hubble the space telescope and seeing
if it's aged at all," Grunsfeld said in a crew video beamed to Earth late
Wednesday.
Hugging
Hubble
Grunsfeld last
visited Hubble in 2002 alongside Atlantis skipper Scott Altman and fellow
spacewalker Michael Massimino. But this mission is the fifth and final flight
to send
humans to revive and renew Hubble.
"Let's do
this," Feustel said as he floated into the shuttle payload bay.
NASA
initially canceled the $1.1 billion flight in 2004 citing it as too risky in
the wake of the Columbia shuttle disaster, but later reversed that decision
after successfully resuming shuttle flights and testing inspecting and repair
techniques. If all goes well, the Atlantis astronauts hope to extend Hubble's
life through at least 2014.
Atlantis
launched toward Hubble on Monday and arrived two days later at the telescope's
350-mile (563-km) high orbit. NASA is keeping a lookout for space debris, which
is present in higher numbers in Hubble's neighborhood than the 220-mile
(354-km) altitude of the International Space Station.
A remnant
from a weather satellite destroyed in a 2007 Chinese anti-satellite test zipped
close by Atlantis late Wednesday, but not
close enough to require the astronauts to fire the shuttle's engines and
dodge the space junk, NASA officials said. NASA has a second ship, the shuttle
Endeavour, on standby as a rescue craft if needed.
New
cosmic vision
During
their spacewalk today, Grunsfeld and Feustel will install Hubble's new Wide
Field Camera 3, a replacement for an older camera that has been the space
telescope's workhorse imager for nearly 16 years.
They will
have to watch what they grab at the beginning. Images of Atlantis' cargo bay turned
up some white particulate contamination on handrails near their work site and
the astronauts must make sure they don't stir it up into Hubble's delicate
inner workings.
The new
camera weighs 900 pounds (408 kg) and is about the size of a baby grand piano.
Hubble scientists hope to use the new camera to probe deeper into the evolution
of galaxies and the shed new light on the mysteries of dark matter and dark
energy.
"We expect
a huge amount of science to come out of it," NASA's astrophysics division
director Jon Morse told reporters here at the Johnson Space Center.
Wide Field
Camera 3 will replace its predecessor - Wide Field Camera 2 - which holds a
special place in the hearts of Hubble scientists. The last image from the older
camera was taken the day Atlantis launched.
Installed
in 1993, that older camera carried some of the first corrective mirrors for
Hubble's blurry vision and is responsible for capturing many of the telescope's
iconic
cosmic images, such as the "Pillars of Creation" in the Eagle Nebula. Since
2007, when Hubble's main Advanced Camera for Surveys failed, the older imager
stepped up to help fill in for the lost instrument, mission managers said.
Grunsfeld
and Feustel will pack the older camera away for the return trip to Earth and
then turn their attention to a vital repair.
They plan
to replace a device on Hubble that routes data and images from the telescope to its
mission operations center in Earth.
The system
failed unexpected last fall - just weeks before the Atlantis astronauts
initially planned to launch toward Hubble. The glitch forced NASA to delay
Hubble's last overhaul for seven months until a spare could be rebuilt.
Grunsfeld
and Feustel will wrap up their first spacewalk by adding a docking berth at the
end of Hubble so a robotic spacecraft can fly up to the telescope when its
mission is ultimately over and send it to a fiery death in Earth's atmosphere.
"Seeing
Hubble coming into the payload bay was pretty amazing, and rendezvous was fun,"
Feustel said Wednesday in a crew video. "Now we're ready to go."
SPACE.com
is providing continuous coverage of NASA's last mission to the Hubble Space
Telescope with senior editor Tariq Malik in Houston and reporter Clara
Moskowitz in New York. Click
here for mission updates, live spacewalk coverage and SPACE.com's
live NASA TV video feed.
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