Astronauts to Say Goodbye to Hubble Telescope

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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