From here on out, the Hubble Space Telescope is on its own. Astronaut Megan McArthur released the mighty scope from space shuttle Atlantis's robotic arm at 8:57 A.M. (Eastern Daylight Time) today, marking the likely end of all direct human contact with Hubble.

The shuttle crew performed numerous repairs and upgrades in five spacewalks spanning nearly 37 hours, in the hope of extending the 19-year-old telescope's life for another five to 10 years. The space shuttle program is set to be phased out next year, a move that will leave the U.S. without a manned space-launch system until at least 2015, and another mission to Hubble is not planned.

The Hubble Space Telescope has received its last upgrades and repairs. The fifth and final spacewalk of the last shuttle mission to Hubble ended at 3:22 P.M. (Eastern Daylight Time), wrapping up an ambitious and remarkably successful servicing operation.

The Hubble team hopes that the fixes will keep the telescope alive for several years, maybe even a decade or more, long after the space shuttle's scheduled retirement next year.

In today's spacewalk, the third of this mission for Drew Feustel and John Grunsfeld, the astronauts replaced three of Hubble's six massive batteries, which have powered the spacecraft during the night portion of its orbit for all of its 19 years in space. (The other three were swapped out in an earlier spacewalk.) Feustel and Grunsfeld also replaced a faulty Fine Guidance Sensor, one of three that helps to point the telescope, and installed a new set of external thermal blankets.

The second of five spacewalks on the servicing mission to the Hubble Space Telescope is in progress, with astronauts Mike Massimino and Michael Good swapping out old parts on the 19-year-old telescope to help extend its lifetime in space.

Massimino (also known as Astro_Mike, the tweeting astronaut) and Good ventured out of space shuttle Atlantis at 8:49 this morning (Eastern Daylight Time) to replace Hubble's three pairs of gyroscopes, which measure the telescope's motion and help keep it pointed in the proper direction.

As with yesterday's spacewalk, the astronauts have hit some minor snags: One of the two-gyro units refused to mount properly, so the spacewalkers retrieved a refurbished spare to use in its place. The delay pushed the spacewalk roughly an hour behind schedule.

Two spacewalkers outside space shuttle Atlantis have begun repairing and upgrading the Hubble Space Telescope as part of the fifth and final Hubble servicing mission. The first of five spacewalks planned for the mission began at 8:52 A.M. today (Eastern Daylight Time) and was expected to take six and a half hours.

Top on the agenda was removing Hubble's Wide Field Planetary Camera 2 (WFPC2), a workhorse with more than 15 years of service. Astronauts Drew Feustel and John Grunsfeld replaced WFPC2 with the new Wide Field Camera 3 (WFC3), which will cover a broader range of the electromagnetic spectrum.

Atlantis is in its final approach to the Hubble Space Telescope, closing in for a scheduled rendezvous at 12:54 P.M. Eastern Daylight Time. After the shuttle catches up to the telescope in orbit and draws within 35 feet, astronaut Megan McArthur will maneuver the shuttle's robotic arm to grasp Hubble and pull it into Atlantis's payload bay.

Tomorrow the real work starts, with the first of five scheduled spacewalks designed to replace aging or faulty components and install two new scientific instruments on the 19-year-old observatory.

During yesterday's standard inspection of the shuttle's heat shield using boom-mounted sensors, NASA spotted some nicking near where the right wing meets the fuselage.

Astronauts aboard space shuttle Atlantis are inspecting the orbiter's heat shield for damage to ensure that the shuttle is capable of re-entering the atmosphere at the end of its servicing mission to the Hubble Space Telescope.

Atlantis's launch yesterday afternoon from Kennedy Space Center in Florida appeared uneventful. But inspection of the shuttle's underside and leading edges is now a routine procedure following the loss of Columbia in 2003, when the shuttle broke up during reentry after sustaining damage to its heat shield from a piece of falling foam insulation at launch.

The weather looks fine, the astronauts have climbed aboard, and all preparations appear to be going smoothly for today's afternoon launch of space shuttle Atlantis on its mission to repair and upgrade the Hubble Space Telescope. The launch, postponed from last October to deal with electronic problems that arose in September, is scheduled for 2:01 (Eastern Daylight Time) from Kennedy Space Center in Florida.

The seven astronauts on the 11-day mission will deliver new scientific instruments and a slew of replacement parts for Hubble, including a set of new 125-pound (57-kilogram) batteries to replace the six originals that have powered Hubble's night-side activities since its 1990 launch.