This story was updated at 9:48 a.m. EDT.
HOUSTON — Atlantis astronauts bid a fond farewell to the Hubble Space Telescope Tuesday and released it back into orbit after the last-ever service call on the beloved observatory.
With smooth precision, astronaut Megan McArthur hauled the refurbished space telescope out of Atlantis' cargo bay and gingerly placed it back in orbit. The shuttle's thrusters fired and it slowly pulled away from the 19-year-old Hubble after nearly a week of work to extend the telescope's life through the next five to 10 years.
"Houston, Hubble has been released," Atlantis commander Scott Altman radioed Mission Control. "It's safely back on its journey of exploration as we begin the steps to conclude ours."
Altman and his crew are due to return home on Friday to land at NASA's Kennedy Space Center in Florida.
Farewell to Hubble
Atlantis' 11-day trip to Hubble is NASA's fifth and last, ever, to overhaul the space telescope before the agency retires its aging shuttle fleet next year. The astronauts staged an intense five back-to-back spacewalks to install $220 million worth of new science instruments and perform vital maintenance work and unprecedented repairs.
The astronauts were the only ones to actually see Hubble float away as their shuttle passed out of video range with Mission Control. But people on Earth watched telemetry instead.
Video from Hubble's mission operations center at NASA's Goddard Space Flight Center in Greenbelt, Md., showed flight controllers clapping and smiling as the telescope was released.
"Now Hubble can continue on its own, exploring the cosmos and bringing them home to us as we head for home in a few days," Altman said.
The mission cost about $1.1 billion to extend Hubble's life through at least 2014. Overall, about $10 billion has been invested to launch and refurbish Hubble over the years.
With the telescope released, Atlantis is leaving Hubble's high 350-mile (563-km) orbit to avoid potential damage from the region's higher levels of space junk. The astronauts plan to scan their heat shield for dings later today in a now-standard late inspection.
NASA once canceled Atlantis' mission following the Columbia disaster because of its added risk, since the shuttle cannot ferry its crew to the International Space Station if it suffers irreparable damage. The station flies lower than Hubble, about 220 miles (354 km) above Earth, and in a very different orbit.
NASA later reinstated the mission after resuming shuttle flights with the caveat of having a rescue ship ready to fly. That rescue ship, Endeavour, has maintained a silent vigil atop a launch pad in Florida since Atlantis launched on May 11.
A better than new Hubble
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 attached a docking ring that will allow a future robotic craft to link up with Hubble and send it plunging into the Pacific Ocean when its mission ends in the 2020s.
Spacewalkers 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. The 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.
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 its first service call.
Three other visits by astronauts in 1997, 1999 and 2002 have been flown to steadily upgrade the telescope. A total of 16 astronauts have visited Hubble to upgrade its systems. They performed 23 spacewalks over about 166 hours and six minutes - the equivalent of an entire month of average workdays when strung together, NASA said.
Hubble program manager Preston Burch said late Monday that the mission's success felt like winning the Super Bowl. With its new instruments and repairs, Hubble is almost a completely new telescope, he added.
Jon Morse, chief of NASA's astrophysics division, said the scientists are already lining up to use the revamped Hubble's instruments.
"We have literally thousands of astronomers out there around the world waiting to use these new capabilities," Morse said. "And they are chomping at the bit to get their data."
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.