The crew of the U.S. space shuttle Atlantis has said its final goodbye to the Hubble Telescope, after conducting days of complex repairs that are meant to give the aging camera at least five more years of clear vision.
Astronauts aboard the Shuttle Atlantis released the telescope back into space Tuesday as it was orbiting 560 kilometers above the coast of Africa.
"Hubble now back on its own for the final time with the gentle release by one, but carrying the fingerprints of hundreds of thousands," said Kyle Herring of the U. S. space agency NASA.
Herring marked the occasion with a tribute to the many people who have worked on the Hubble since its 1990 launch.
The seven-member crew that made the latest repairs will be the last to touch the telescope. NASA plans to retire its shuttle fleet next year. A replacement for Hubble is expected in a few years.
As the crew cast the Hubble back into space with the shuttle's mechanical arm, Atlantis Commander Scott Altman reflected on the difficulty of the mission.
"I think it's demonstrated the triumph that humans can have when they overcome challenges that are presented to them. "Not everything went as we planned. But we planned a way to work around everything," Altman said.
While working in an orbit cluttered with debris, the astronauts were left cursing at times as they struggled with frozen bolts and other challenges during their five daily spacewalks.
Despite that, they managed to install a new $132-million camera and a piece of sophisticated equipment called a spectrograph that will help further explain how planets, stars and galaxies were formed.
They also replaced delicate circuit boards and added new batteries that NASA says should keep the telescope working until at least 2014.
During the past 19 years, Hubble's spectacular photographs of galaxies and newborn stars have redefined human understanding of the universe, and forced astronomy books to be rewritten.
Ed Ruitberg, the deputy program manager for the Hubble, says those textbooks may need to be rewritten again because the telescope is now more powerful than ever.
He says the upgraded camera could even help answer the one question on everyone's mind.
"Are we alone? That's one of the questions. So when we start testing atmospheres of other planets, we're trying to determine are there habitable places elsewhere in the universe to sustain life," Ruitberg said.
While astronomers ponder that question, the Atlantis crew will return to the planet they know best. They are scheduled to head back to Earth on Friday.