HOUSTON -
Atlantis astronauts will say goodbye to the Hubble Space Telescope for the last
time Tuesday.
The seven
astronauts aboard Atlantis will pluck the 19-year-old telescope from its perch
in the shuttle cargo bay Tuesday morning and release it back into space. The
shuttle will then fire its engines to leave Hubble's the 350-mile (563-km) high
neighborhood for a lower orbit.
The move
caps nearly a week of intense
Hubble repairs and five amazing spacewalks by Atlantis astronauts to add
new $220 million worth of new instruments and upgrades, as well as
unprecedented repairs. By the end of their last spacewalk on Monday, they had
accomplished all of their goals plus some extra work, leaving Hubble more
powerful than ever.
"It's been
a real thrill," said Atlantis commander Scott Altman.
Altman and
his crew are due to return to Earth Friday and will tweak their orbit a bit
today to put them on course for an earlier landing in Florida.
Catch
and release
Today,
astronaut Megan McArthur will release Hubble using the robotic arm aboard
Atlantis, but it was her crewmate John Grunsfeld - who is making his third trip
to the observatory - who actually gave the telescope the last
pat farewell during the mission's final spacewalk.
"Happy
voyages," Grunsfeld said to Hubble during a lighthearted crew video on Monday.
"It's hard not to think of Hubble as something alive, but I really was thinking
of Hubble as a friend."
Atlantis'
trip to Hubble is NASA's fifth and last, ever, service call to the space
telescope before the agency retires its aging shuttle fleet next year. The
agency's capsule-based replacement is smaller, lacking the robotic arm needed
to snare Hubble and the shuttle's 60-foot (20-meter) cargo bay to store large
instrument replacements.
The
astronauts launched from the NASA's Florida spaceport on May 11, leaving its sister ship
Endeavour atop a second launch pad, where it has stood ready to fly a rescue
mission should Atlantis suffer irreparable damage during the mission. The
shuttle cannot reach the safe haven of the 220-mile (354-km) International
Space Station from Hubble because it is higher and in a very different orbit.
NASA once
canceled Atlantis' mission because of that risk following the Columbia
disaster, but later reinstated the mission with the caveat of having a rescue
ship ready to fly. The region around Hubble is littered with space trash and
the Atlantis crew inspected their shuttle's heat shield soon after launch.
Mission
managers found the shuttle in good health after its launch, with Atlantis
astronauts to take a now-standard second look at their heat shield for signs of
new damage while they have been in space.
Goodbye,
Hubble
By NASA's
scorecard, the flight has been an undeniable success despite daunting spacewalk
repairs that revived a pair of long-dead instruments. Their work should leave Hubble
more capable than ever to take its trademark cosmic images and
peer back to about 500 million years after the birth of the universe.
Altogether,
the astronauts installed a brand new wide-field camera for deep-space
observations, a super-sensitive spectrograph to detect faint light from distant
quasars, as well as new gyroscopes, batteries, a fine guidance sensor for
pointing accuracy and insulation.
They also
resurrected Hubble's advanced camera and a versatile spectrograph that can
double as an imager. Those damaged devices were never built to be fixed in
space.
Now, all of
Hubble's instrument bays are full, something the telescope hasn't seen since 1993
when astronauts removed one to install corrective mirrors to fix the
then-ailing observatory's blurry vision during the first service call. Three
more visits by astronauts then followed in 1997, 1999 and 2002 to steadily
upgrade the telescope.
"There are
already some bittersweet feelings," Hubble program manager Preston Burch told
reporters Monday here at NASA's Johnson Space Center. "We're extremely pleased
with the success of the mission and happy. But on the other hand, we're sad
that this will be the last time we see it."
Jon Morse,
chief of NASA's astrophysics division, said that full performance checks for
Hubble's new instruments should be completed by the end of summer. But already,
thousands of scientists are waiting in line to use Hubble once the new
instrument system checks are completed at the end of the summer, he added.
"We have a
saying in the science mission directorate, 'Science Never Sleeps,' and our work
is just beginning," said Jon Morse, chief of NASA's astrophysics division. "We
can't wait to get out there and use Hubble for its intended purposes."
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 and SPACE.com's live NASA TV video feed.
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