This story was updated at 6:40 p.m.
EDT.
HOUSTON - Spacewalking astronauts
finished their hands-on repairs on the Hubble Space Telescope Monday, wrapping
up a five-day marathon to overhaul the much-loved observatory for the last
time.
Atlantis astronauts John Grunsfeld
and Andrew Feustel spent just over seven hours adding some final upgrades to 19-year-old
Hubble more powerful than ever before. It was an emotional day for the
astronauts, as they became the last people ever to touch the iconic space
telescope.
"This is a really tremendous
adventure that we've been on, a very challenging mission," said Grunsfeld, a
self-described Hubble
hugger making his third trip to the telescope, as he finished his work.
"Hubble isn't just a satellite, it's about humanity's
quest for knowledge."
Monday's spacewalk was the fifth and
last for the Atlantis crew, with astronauts soaring through all of their tasks
in just over seven hours. Their mission is NASA's fifth and final service call
on the Hubble, and the last chance to extend
its life through at least 2014 with state-of-the-art instruments.
"Hubble is returned to flagship
status," said Jon Morse, director of NASA's astrophysics division. "It now has
a full arsenal of instruments and tools for astronomers to make new discoveries
during the next several years."
The astronauts are slated to release
Hubble back into space on Tuesday. Their 11-day mission cost about $1.1 billion
and caps a $10 billion investment in the Hubble Space Telescope, which launched
in 1990.
Hubble's last hug
During their spacewalk, Grunsfeld
and Feustel replaced Hubble's batteries, installed a new guidance sensor to
fine-tune its pointing ability and added some sorely needed steel-foil
insulation covers to the telescope's hull.
The covers protect Hubble from the
extreme temperature swings and radiation in space. The telescope's older
insulation was in bad shape, shedding shiny, harmless bits as Grunsfeld tucked
it in a trash bag.
"Wow, look at Hubble," one of the
spacewalkers said after installing the gleaming new metal covers.
The astronauts were determined to
leave Hubble in the best condition they could. They began Monday's spacewalk an
hour early in order to squeeze in time to install more insulation, including a
cover NASA packed along just in case they had extra time.
After finishing their work, the
astronauts took time to take photographs of Atlantis, themselves and finally
Hubble.
"This is really a great day,"
Mission Control radioed the spacewalkers, adding it was "a great way to close
things out."
But the spacewalkers had one last,
unexpected task. They had to replace an antenna cover on Hubble after one of
them accidentally bumped it.
"Sorry, Mr. Hubble," Grunsfeld said.
"Have a good voyage."
"Consider it a goodbye kiss, John,"
astronaut Michael Good called out from inside Atlantis.
A deeper view
Since their May 11 launch, Atlantis
astronauts have added a powerful new wide-field camera to peer deep into the
universe and installed a super-sensitive spectrograph to study the structure
and composition
of the cosmos.
The new $220 million additions
should extend Hubble's vision back to about 500 million years after birth of
the universe, which is 13.7 billion years old. Hubble could peer back to about
700 million years after the theoretical Big Bang before the Atlantis crew
arrived.
Atlantis astronauts also made two
unprecedented repairs to Hubble's broken advanced camera and an older, more
versatile spectrograph that doubles as an imager. Both of those instruments
were never designed to be fixed in space. Atlantis astronauts revived them in
two nail-biting spacewalks.
"On this mission, we tried some
things that some people said were impossible," Grunsfeld said. "We've achieved
that, and we wish Hubble the very best."
Then there's the vital maintenance
work, which replaced aging gyroscopes, batteries and finicky science data
computer. The astronauts also added a docking ring to Hubble that will allow a
robotic spacecraft to latch on and send it down into the Pacific Ocean when the
telescope's mission ends sometime in the 2020s.
"In many ways, it is a brand new
observatory," Hubble program manager Preston Burch told reporters here at
NASA's Johnson Space Center. "One far more capable than what
was launched in 1990."
Burch said the initial round of
system checks should last through late summer, when the first results and
images from the revamped Hubble should be ready.
NASA canceled the mission in 2004
after the Columbia disaster because of its risk, but reinstated it three years later once shuttle missions resumed. Part of the
reasoning for the reversal is the shuttle Endeavour, which has been sitting on
a launch pad in Florida poised to fly a rescue
mission if needed, since Atlantis lifted off.
Astronauts visiting Hubble have no
safe haven if their shuttle is damaged beyond repair. The International Space
Station serves as a refuge for its visiting shuttle crews, but is beyond the
reach of Hubble-bound astronauts because of its lower altitude and different
orbit.
Monday's spacewalk marked the third
spacewalk for Feustel and the eighth career excursion for Grunsfeld - who
finished with 58 hours and 30 minutes of spacewalking time - making him the
world's fourth most experienced spacewalker. Feustel ended the spacewalk with a
mission total of 20 hours and 58 minutes.
It was also the 23rd spacewalk at
the Hubble Space Telescope. In all, astronauts have spent 166 hours and six
minutes working on the space observatory.
The Atlantis crew is due release
Hubble back into space early tomorrow and land Friday at NASA's Kennedy Space
Center in Florida.
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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