 | Scientists Call Hubble a 'Whole New Telescope' After Repairs By Tariq Malik Senior Editor posted: 26 May 2009 06:27 pm ET |
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."
