CAPE CANAVERAL, Fla.— Space shuttle Discovery and its crew of seven returned to Earth today and capped a successful expansion job at the international space station, more spacious and robust thanks to a new billion-dollar science lab.

The shuttle descended through a few puffy clouds and landed at 11:15 a.m., under the control of its commander, Mark Kelly.

Two hours later, all the astronauts — including Garrett Reisman, looking remarkably fresh and fit after 95 days in space — walked out, shook hands with NASA’s senior managers, and admired the ship that safely brought them home.

At a news conference later in the day, a first for an astronaut returning from a long space mission, Mr. Reisman said he felt better than he expected and attributed that, in large part, to being short. His sensory organs are closer to his center of gravity and his heart is closer to his brain for pumping blood, and he believes that may be why he didn’t suffer the typical balance problems.

“I think maybe we’re on to something here. We need to get more short people in the astronaut office,” Mr. Reisman said, laughing. “I’m happy that it’s finally come in handy for something other than limbo contests.”

While still in orbit, Mr. Reisman described in quite romantic terms how much he missed his wife, Simone Francis — “my favorite Earthling.” Their reunion, he said, was “everything I was hoping for.”

“She got a haircut, actually, while I was gone and so I hesitated for a moment as soon as the doors to the elevator opened and I saw her,” Mr. Reisman told reporters. “But it was fantastic and it was a very tender moment when I got a chance to go over and hold her again.”

Discovery’s flight spanned 14 days, 217 orbits and 5.7 million miles, and was described by NASA as being about as smooth as it gets.

“It’s great to be here on the runway in sunny Florida,” Mr. Kelly said after exiting the shuttle. “It was really an exciting mission.”

Mr. Kelly and his crew accomplished everything they set out to do in orbit. They delivered and installed Japan’s Kibo lab, now the space station’s biggest room and most sophisticated science workshop, and dropped off a new pump that the two Russians on board used to fix their toilet.

The space station also got a new American resident who took Mr. Reisman’s place.

NASA’s associate administrator, Christopher Scolese, reveled in the “outstanding” successes of the past month: landing a spacecraft on Mars and scooping up dirt, and seeing the space station grow, and “looking really like a space station,” with the Discovery crew’s help. The space agency also launched a telescope into orbit last week to search the universe for elusive gamma rays.

Although the mission itself unfolded almost flawlessly, Discovery left behind a battered launch pad on May 31. Some 5,300 bricks flew off the flame trench when Discovery blasted away, most likely because they were not attached properly to the underlying concrete wall when the pad was built in the 1960s for the Apollo moon shots.

NASA managers are confident the launch pad can be fixed in time for the next shuttle flight in October, by Atlantis to the Hubble Space Telescope.

The next time a shuttle flies to the space station, now three-quarters complete, isn’t until November. That’s because NASA needs to have a shuttle ready to rush to Atlantis’ aid in case of serious damage to its thermal shielding. Atlantis’ astronauts will not be able to get from Hubble to the space station for shelter.

NASA had no such rescue plan in place when Columbia took off in 2003 on a solo-flying research mission. In any event, mission managers had no idea Columbia’s left wing was severely damaged at liftoff, and the shuttle shattered during re-entry. All seven on board were killed.

Shades of Columbia briefly surfaced yesterday when Discovery’s astronauts spotted something floating away from their spaceship. It turned out to be a little metal clip that broke off the rudder, and engineers ascertained within just four hours that its absence posed no danger for Discovery’s re-entry.

The three space station residents watched Discovery’s smooth landing on live TV transmitted from Mission Control. Astronaut Gregory Chamitoff, who’s just starting a six-month mission, called it “an awesome sight.”

“Before you know it, you’ll be catching your own ride home,” Mission Control said.

Ten shuttle flights remain before the fleet is retired in 2010, all but one to the space station.

The launch director, Mike Leinbach, said he’s encouraging his team to take time off this summer, since there are no flights, and rest up for a busy fall. The shuttle work force finds itself in the unusual position of scheduling summer vacations and actually being able to take them on time, he said.

“It’s a good feeling for us,” Mr. Leinbach said, smiling.