Space shuttle Columbia's robotic arm reached out and captured the 12 1/2-ton Hubble Space Telescope at 4:31 a.m. EST this morning, setting the stage for five spacewalks to service and upgrade the observatory starting Monday morning.

"Houston, we have Hubble on the arm," commander Scott Altman radioed when the robot arm's snares captured a grapple fixture on the telescope as the two spacecraft flew 362 miles above the Pacific Ocean, southwest of Central America.

"Copy, Scooter, outstanding work," replied astronaut Mario Runco from mission control. "And there's a big sigh of relief we heard from Goddard all the way here."

"I think it echoed up here as well," Altman said.

The arm then mounted Hubble atop the Flight Support System servicing platform in the rear of shuttle Columbia's payload bay.

Basically the workbench for Hubble, the platform features a Lazy Susan-like ring that the telescope actually sits on, allowing the observatory to be rotated and pivoted as needed to provide the best available access to various worksites for spacewalkers.

Later in the morning the observatory's twin solar arrays -- 40-foot-long, 10-foot-wide flexible wings -- were rolled up so spacewalkers can remove them during EVAs planned for Monday and Tuesday. The arrays will be replaced with new, more powerful ones.

"And we've got a winner on both sides," astronaut Steve Maclean radioed the crew from mission control. "It's a good start to five more great EVAs."

The old arrays weigh 339 pounds each and generate about 4,600 watts of power from silicon solar cells. The new arrays wings that will be installed Monday and Tuesday weigh 640 pounds each. But they're smaller -- just 23 feet long -- and 30 percent more powerful, generating 5,270 watts using gallium arsenide solar cells.

If the arrays failed to retract, then spacewalkers would have tossed the structures overboard as was the case with one array during the first Hubble servicing in December 1993.

"It's a great day in space," said Wayne Hale, a senior flight director serving as NASA's mission operations representative for this flight. "We have the Hubble Space Telescope, which is probably the premier scientific instrument of our generation, berthed in the payload bay, ready to be refurbished and renewed and in five or six days, sent back out to uncover more and exciting things about our universe. We've had a great flight so far and everything today has gone just exceedingly well."

Preston Burch, Hubble program manager at the Goddard Space Flight Center in Greenbelt, Md., agreed, saying "we're off to a really great start for this mission."

"It's always a very exciting time for us on the ground to see Hubble come into view from out in the distance as we approach it, to see the increasing level of detail that comes into view," he said at a morning status briefing. "Of course, we're always very interested to know how it's fared over the past few years since it was serviced the last time. And I can say right now Hubble is in excellent shape."

Using cameras on Columbia's robot arm, the astronauts have begun a detailed photo survey of Hubble. "Our initial examination of the exterior of the observatory does not indicate any significant or noticeable changes since December 1999 when it was serviced last," Burch said.

"The solar array retraction procedure today went extremely smoothly and all the other systems are go, the space support equipment that is located in the payload bay of Columbia has all been thoroughly checked out and is working just as you'd expect it to," he added. "So right now, HST is go for EVA day one, tomorrow, and they will be (replacing) the first of the solar array wings. We're looking forward to accomplishing all of our objectives on this mission. We're very pleased so far."

The astronauts have gone to bed for an eight-hour sleep period. They are due to be awakened at 8:52 p.m. EST tonight to prepare for the first spacewalk. That EVA by John Grunsfeld and Rick Linnehan is slated to start at 1:27 a.m. EST Monday, but lead flight director Bryan Austin said the astronauts probably will begin the excursion early, possibly up to an hour ahead of schedule, to get a leg up on a busy day in space.