MIAMI – The Hubble Space Telescope, responsible for some of astronomy’s most startling and visually bewitching discoveries, received a reprieve Tuesday.

Reversing a previous decision that dismayed scientists and schoolchildren alike, NASA managers authorized a risky space shuttle mission to repair the 16-year-old orbiting telescope and prolong its life.

“The answer is yes,” said Mike Griffin, head of the National Aeronautics and Space Administration, who worked on the Hubble project earlier during his career.

The announcement cheered champions of science, young and old.

“Children send the Hubble questions like, “Do you have a picture of God and can you send it to me?’ “Have you seen an angel today?’ “Can you find my cat?”‘ said Sen. Barbara Mikulski, D-Md., who had lobbied for the mission.

“It’s a great day for science,” she said. “It’s a great day for discovery.”

Launched on April 24, 1990, and named for astronomer Edwin Powell Hubble, the telescope has recorded about 750,000 images of 24,000 celestial objects for 4,000 astronomers who have published 6,300 papers based on the research, according to NASA.

Among the telescope’s discoveries and other accomplishments: 16 planets that orbit distant stars, a glimpse of the universe as it existed 12 billion years ago, evidence of an atmosphere on a planet in another solar system, confirmation of additional moons around Pluto, and detailed photos of our galaxy.

The 11-day repair mission is tentatively scheduled for May 2008 aboard shuttle Discovery. It will require four or five spacewalks 375 miles above Earth. It will cost about $900 million, NASA said.

Scientists and engineers plan to add two new cameras to Hubble, repair a key instrument called a light-separating spectrograph, boost the telescope into higher orbit and upgrade batteries and other equipment.

If successful, the repairs should keep Hubble operating until 2013, extending its productive life by about four years.

But the flight will be more risky than the three most recent – and other future – shuttle missions because the crew will not have the option of parking a damaged shuttle at the International Space Station.

Since the Columbia accident of February 2003, which killed all seven of its astronauts, NASA has required the “safe haven” option for every launch it authorizes.

The space station and the telescope, however, orbit Earth at different angles and altitudes. A shuttle bound for Hubble and crippled by launch debris or other problems would not be able to reach the space station.

As a result, former NASA Administrator Sean O’Keefe canceled the Hubble repair mission about 2½ years ago, igniting protests from scientists and many others.

Under the new plan, NASA will continue to work on techniques to repair shuttles in flight, Griffin said Tuesday during an employee meeting at the Goddard Space Flight Center in Greenbelt, Md.

NASA also will have another shuttle poised for launch on a mission to rendezvous with Discovery and rescue its crew, should that become necessary.

“We’re not going to risk a crew in order to do a Hubble mission,” Griffin said.

Over the years, four previous shuttle missions repaired or updated the 45-foot-long, 13.5-ton telescope.

Elliot Pulham, president of the Space Foundation, a Colorado-based group that supports space exploration, praised Tuesday’s action.

“The images and discoveries that have come back from Hubble have been profoundly altering to our understanding of our place in the universe,” Pulham said. “This kind of exploration is equally as important as human exploration.”