The Hubble
Space Telescope appears better than new as NASA puts the 19-year-old
observatory through a battery of tests after its final facelift by an astronaut repair crew.
Ed Weiler, NASA's
science missions chief, said Hubble is in the midst of meticulous systems and
calibration checks following the successful
upgrades and repairs by Atlantis shuttle astronauts.
"All of
those have gone beautifully," Weiler told reporters after Atlantis' smooth
California landing on Sunday. "Everything is going well, as far as I can tell."
The
calibrations and electronics tests should run their course by the end of
summer, with a new and improved Hubble once more ready for science observations
in late August, Weiler said.
Atlantis
and its crew of seven astronauts touched
down at Edwards Air Force Base in Southern California at 11:39 a.m. EDT
(1549 GMT) on Sunday, though it was early morning at their desert runway. The
astronauts returned triumphant after a 13-day Hubble service call.
"Now and
only now can we declare this mission completely a success," said Weiler,
who served as Hubble's chief scientist between 1979 and 1998. "The astronauts are safely on the
ground."
Commanded
by veteran spaceflyer Scott Altman, the Atlantis astronauts launched toward
Hubble on May 11 and performed a five-spacewalk marathon that left the iconic
space observatory more powerful than ever before.
A whole
new telescope
Atlantis'
mission was NASA's fifth and last-ever shuttle flight to overhaul Hubble. NASA
plans to retire its three aging space shuttles fleet next year and their
replacement, the capsule-based Orion, is designed to ferry astronauts to the
International Space Station and, ultimately, the moon.
During
their five back-to-back spacewalks, Atlantis astronauts installed two new
instruments in Hubble - a powerful wide-field camera and a super-sensitive
spectrograph.
They
swapped out old gyroscopes and batteries with new ones, performed two intricate
repairs to revive
two instruments - Hubble's main Advanced Camera for Surveys and a versatile
imaging spectrograph - that were never designed to be fixed in space.
The
enhancements, he added, should be the focus, and not the fact humans will never
visit the space telescope again.
"We just
repaired the Hubble Space Telescope," an emphatic Weiler said. "We've got a
whole new telescope. We've got four new instruments. Two of them dead, now
alive.
"These are
truly the best of times," Weiler said. "Not the worst of times."
The
upgrades by the Atlantis crew should extend the space telescope's life through
at least 2014 if not longer, which would overlap with NASA's next great
observatory - the infrared-scanning James Webb Space Telescope slated to launch
in 2013.
Atlantis
spacewalkers also attached a docking ring to Hubble so that, sometime after
2020, a robotic spacecraft can latch onto the telescope and discard it in the
Pacific Ocean at its mission's end.
Hubble
see saw
Weiler said
the success at Hubble is even more poignant since the mission almost never
happened.
In 2004,
just a year after the tragic loss of the shuttle Columbia and its crew, NASA
canceled the mission because of its risk. Hubble-bound astronauts would not be
able to reach the safety of the International Space Station because of the
telescope's higher altitude and completely different orbit.
Weiler and
Hubble scientists were crushed, especially since Hubble was designed to be
visited by astronauts every two or three years for vital
maintenance.
It was an
astronaut crew that fixed Hubble's blurry vision during a 1993 service call,
just three years after the space telescope launched into space with a flawed
mirror. That mission transformed Hubble from a national joke into "a great
American comeback story," Weiler said.
By 2004 -
two years after its most recent upgrade - the telescope was again in need of
repairs. Instead, the mission was cancelled on Jan. 16, 2004, the day after
Weiler's birthday.
"If you
would have told me on that day that I would be sitting her five years later,
with a totally successful five-[spacewalk] mission, with a brand new Hubble
once again that will probably operate into a third decade, I wouldn't have bet
you a penny," Weiler said. "This mission is a great success."
NASA
resurrected the Hubble-bound mission in 2006 after resuming shuttle flights and
successfully demonstrating heat shield repair techniques and tools.
It was heat
shield damage to Columbia's left wing that doomed that shuttle and it's
astronauts during re-entry. During the Hubble flight, NASA kept the shuttle
Endeavour on standby to fly an unprecedented a rescue mission in case Atlantis
suffered similar damage. No rescue was needed.
NASA plans
to launch up to eight more shuttle flights by 2010 to complete the space station's
construction. The orbiting lab is expected to reach its full six-person crew
size later this week when three new spaceflyers join the station's current
three-man crew.
The next
shuttle to launch will be Endeavour, which will move from its current perch
atop Launch Pad 39B to the nearby Pad 39A early on May 30 for a planned June 13
launch toward the space station.
Pad 39A is
NASA's prime shuttle launch site. Pad 39B will be turned over to the shuttle's
replacement booster – the Ares I rocket. The first test flight, Ares I-X, is
slated to launch no earlier than Aug. 30.
The
Atlantis astronauts are the last humans ever to touch or see
Hubble up close. When they left the telescope last Tuesday, they recorded
the departure from Hubble and later beamed it back to Earth.
"All of us
had, I wouldn't say wet eyes," said Weiler. "But it was an emotional moment
because we knew that was probably the last time humans would see Hubble."
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