After undocking from the space station, Shuttleworth and the crew backed away a safe distance before firing their braking rockets at 10:57 p.m. Saturday EDT (0257 Sunday GMT) to begin a one-hour freefall toward Kazakhstan.

Left behind on the frontier outpost were Expedition Four commander Yuri Onufrienko, and flight engineers Dan Bursh and Carl Walz, who will now begin the final stretch of what is likely to be a six-month stint aboard the station.

Having said farewell and thanks to the Soyuz taxi crew for bringing them a fresh emergency lifeboat, the station crew did their best to record images of the Soyuz's departure.

"We could feel a little clunk onboard," Bursch later reported to Mission Control in Houston about the Soyuz undocking. "I'm sorry I can't think of a more technical word."

"Clunk sounds like a good technical term to us," replied astronaut Mark Polansky from the station control room.

A moment later, Walz made his report: "I wasn't in the lab. I didn't hear the clunking noise. To me it was more of a clinking noise."

"We'll note that it was clinking for you and clunking for Dan," Polansky deadpanned.

Shuttle Endeavour remains targeted for launch May 30 from the Kennedy Space Center in Florida. The spacecraft is to bring up fresh supplies and a new Expedition crew to occupy the station, and then return Onufrienko, Walz and Bursch to Earth.

Meanwhile, as the Soyuz capsule made its return through Earth's atmosphere, it momentarily became a ball of fire and Shuttleworth said he watched as "metal was melting outside the window'' when unnecessary equipment such as a periscope were left to simply burn up in temperatures of 18,000 degrees Fahrenheit (10,000 degrees Celsius) -- a sight he admitted was "a little disturbing.''

About 14 minutes before hitting ground, a giant parachute deployed and then just a second from Earth, another set of braking rockets fired to cushion the landing. Unlike many past Soyuz landings, this time the capsule didn't end up on its side, but Shuttleworth said later the touchdown was still a rough jolt that made him see stars in front of his eyes.

He was warned earlier to keep his head back, and resist the temptation to peer out the small window at the blue sky rushing away from him to keep from injuring himself. In the past, cosmonauts have walked away with broken teeth, he said.

Shuttleworth joked: "It is euphemistically called a soft landing.''

Shuttleworth's father, Rick, who came to Kazakhstan to welcome his son home, described his relief at seeing the parachute deploy, and then after the landing when his son, still inside the capsule waiting his turn to be lifted out, smiled at him through the window and mouthed that all was OK. When asked what Shuttleworth's first words to his father were, Rick Shuttleworth said his son told him that the landing was "far shakier'' than the takeoff.

Back in Moscow, Shuttleworth's mother, Patronelle, who spent the night at Mission Control, covered her face with her hands during the landing, peeked occasionally at giant monitor, and burst into tears after the successful touchdown was announced.

"Complete and absolute relief,'' she said over and over. "It's not your everyday family experience.'' She said she's been sleeping in snatches over the last week while her son was in space.

In addition to the throngs of medical and space experts and dozens of journalists waiting in the barren steppe to greet the crew, a few curious locals also arrived -- one on horseback -- to marvel at the capsule, still smelling of burning metal after its fiery descent.

Looking relaxed and alert, Shuttleworth said later that he was still a little unsteady on his feet after growing accustomed to floating around in zero gravity. He described the feeling as being like a newborn deer adjusting to unfamiliar legs, and said that he keeps expecting to be able "to just float'' somewhere.

Vittori, who said as a first-time space traveler it was an "incredible experience,'' told journalists that "officially I say that I feel fine, but my head is still spinning.''

Shuttleworth spent eight months with the rest of the crew training for the mission in Russia's Star City and one week at NASA's Johnson Space Center in Houston.

From the beginning, Shuttleworth said he was determined not to be viewed simply as a tourist. He participated in a series of experiments in space, keeping to a schedule that his family said was monitored down to the minute. Shuttleworth's father confessed that his son found the regimented lifestyle the most difficult part of the trip.

After spending a few days in Star City, Shuttleworth's family intends to take him on vacation to give him time to relax. Shuttleworth, though, admitted that he is eager to keep talking about the experience so he doesn't forget it. While Shuttleworth's other two crewmates strictly followed doctor's orders and took a nap on the return plane trip to Moscow, the South African briefly wandered around the plane, saying he just wanted to talk about his trip.

He called the journey "the best thing I've ever done.''

Shuttleworth is also taking home two big souvenirs -- the three-ton remainder of the Soyuz capsule that brought the trio back to Earth and the bulky spacesuit that protected him during the fiery descent.

And when asked whether he would go up again, Shuttleworth gave a big smile and said without a moment's hesitation: "Anytime.''

Jim Banke of SPACE.com's Cape Canaveral Bureau contributed to this report.