HOUSTON – Space shuttle Discovery performed a slow back flip and then docked at the International Space Station on Monday, delivering a mammoth lab and two new occupants: a NASA astronaut and Buzz Lightyear.
Back at the launch site, meanwhile, NASA hurriedly set up an investigation to figure out why the launch pad suffered its worst damage in 27 years of space shuttle flight. Bricks and mortar flew off the pad during Discovery's liftoff Saturday.
Discovery was not struck by any of the debris — engineers pored over the launch pictures to be sure of that, said LeRoy Cain, chairman of the mission management team.
When asked by a reporter if NASA got lucky in that regard, he said: "I don't like to think in terms of luck."
Commander Mark Kelly pulled up to the space station and parked as the two spacecraft soared 210 miles above the South Pacific.
Discovery carried Japan's prized Kibo lab, a 37-foot-long, 16-ton scientific workshop. The seven shuttle astronauts and three station residents will combine forces to install the bus-size lab on Tuesday.
The shuttle crew also brought a spare toilet pump for the orbiting outpost. The space station's Russian-built toilet broke nearly two weeks ago — forcing the crew to perform manual flushes with extra water several times a day — and engineers hope the new pump will take care of the problem.
Astronaut Gregory Chamitoff got his first look at what will be his home for the next six months. He is replacing Garrett Reisman, who has been living at the station since March.
"Garrett, you have a beautiful house," Chamitoff said. "Oh my God, it's so beautiful."
The two men hugged once the hatches between them swung open. It was a group embrace, actually, with the space station's two Russian residents joining in as well.
Also moving in for a half-year is a 12-inch action figure familiar to children almost everywhere: Buzz Lightyear, the character from the 1995 film "Toy Story" that's always yearning to blast off "to infinity and beyond."
Disney sent up the toy as part of NASA's toys-in-space educational program.
Right before linking up with the space station, Kelly guided Discovery through a 360-degree somersault from 600 feet out, allowing Reisman and one of the space station's Russian residents to take zoom-in photos of the shuttle's belly.
The back flip became standard procedure for shuttle flights following the 2003 Columbia tragedy; Columbia was brought down by a hole in the wing, left there by flyaway fuel-tank foam.
Imagery experts will pore over these 302 digital pictures — as well as the multitude of launch images — to see whether Discovery is in good enough shape to re-enter safely on June 14.
As Discovery closed in, Reisman played a recording of C.W. McCall's "Convoy," the 1975 novelty song about truckers.
"Keep on truckin' Discovery," Reisman called out.
"We are really looking forward to seeing you guys," said Kelly.
On Sunday, the astronauts performed a cursory wing inspection using their ship's 50-foot robot arm.
They sent ground controllers images of the upper edges of the wings, but could not check the lower edges of the wings and the nose cap because they lacked the proper laser tools.
Their laser-equipped inspection boom is at the space station, left there by the previous shuttle crew in March. They will retrieve it and, after they depart, perform a full survey.
Discovery did not have enough room for the 50-foot boom — standard equipment on all previous post-Columbia missions — because of the enormous lab filling its payload bay.
About five pieces of foam insulation broke off the external fuel tank during liftoff, and one or two of them may have hit the shuttle. But the pieces, it's believed, came off too late in the launch to do any damage.
Astronaut Karen Nyberg said neither she nor her crewmates saw anything wrong as they were surveying the wings.
"To me, it looked really good," flight director Matt Abbott said from Johnson Space Center. But he cautioned: "We've got a lot of work to do to go through the data."
Discovery's fuel tank was the first one built from scratch with all the post-Columbia safety changes. The tank, at least from the early data, looks to have performed well, said LeRoy Cain, chairman of the mission management team.
As for the launch pad damage, the worst of it, by far, was in the brick-lined trench that is designed to deflect the flames at booster rocket ignition.
A large section of the flame trench — 20 feet by 75 feet — broke apart, and chunks of the large heat-resistant fire bricks and concrete mortar were scattered all the way past the chain-link fence 1,800 feet away. The fence was damaged in places.
The pieces of debris ranged in size from a pebble to entire bricks.
"We're combing the ground as we speak," NASA spokesman Bill Johnson said in early afternoon.
The flame trench — dating back to the 1960s Apollo era — is inspected regularly and undergoes periodic repair, Cain said.
"Something happened specific to this mission," he said at a news conference.
Johnson said it's unlikely any of the bricks hit Discovery because the flame trench is designed to deflect the flames at booster rocket ignition, as well as stones and other debris kicked up by all the power.
There have been no recent repairs to the Apollo-era flame trench that might have caused this sort of damage, and it's never broken like this before, Johnson said.
"We'll just have to wait until the report comes in," he said.
NASA does not need to use the pad again until the next shuttle launch in October.
Cain said the space agency will need to understand what happened — and prevent it from happening again — before another shuttle can take off from that pad.
He said it was unlikely that the October mission — astronauts' final trip to the Hubble Space Telescope — would be delayed as a result of the launch pad damage.