Space Station Crew Back On Earth

Mexican dancers perform a traditional dance in front of The Pyramid or Kukulcan Temple, in the archaeological site of Chichen Itza, Yucatan during celebrations after it was named Saturday, July 7, 2007, as one of the new Seven Wonders of the World. A private Swiss foundation launched the contest in January 2007, allowing Internet and telephone voters to choose between 21 sites short-listed from 77 selected by a jury.
The space shuttle Discovery returned to Earth on Wednesday, leaving a fresh crew behind on the international space station and bringing their three predecessors back to the uncomfortable tug of Earth's gravity after 167 days in weightlessness, reports CBS News Space Consultant William Harwood.

With commander Scott "Doc" Horowitz at the controls, Discovery glided to a high-speed touchdown at 2:23 p.m. to wrap up a 12-day, 4.9-million-mile voyage spanning 186 complete orbits since launching Aug. 10 from nearby pad 39A.

"Houston, Discovery is wheels stopped. And for transfer, items 106, 107 and 108 are complete," Horowitz radioed from the runway, jokingly referring to Expedition Two space station commander Yury Usachev, Susan Helms and James Voss.

"Welcome home to all of you and especially Yury, Susan and Jim, it's great to have you back on Earth," replied astronaut Kenneth Cockrell from Houston.

Clouds and rain near the landing site forced the shuttle to take an extra spin around the world, but the weather by mid-afternoon was good enough for the landing to take place.

Mission Control waited until practically the last minute before giving Discovery's pilots the go-ahead to fire the braking rockets and begin the hourlong descent. "A close call," said commentator Rob Navias.

Discovery left the space station on Monday after dropping off a fresh three-man crew and retrieving commander Usachev and his crewmates.

Their adventure, as they call it, began with their launch aboard Discovery back in March and lasted 167 days — just 21 days shy of NASA's all-time space endurance record. They circled Earth about 2,600 times and logged 70 million miles.

They made the trip back into the unfamiliar tug of Earth's gravity resting in cushioned recliners on the shuttle's lower deck.

Before reaching Florida, Discovery passed directly over Houston at Mach 16, or 16 times the speed of sound. Space station flight controllers warned the orbiting outpost's new commander, Frank Culbertson, in advance that they might be busy right around then.

"If you call us, we may not be able to answer because we might be outside watching it go over," Mission Control said. Culbertson chuckled and replied: "Understand."

Usachev, Voss and Helms face at least six weeks of rehabilitation. Muscles and bones weaken in weightlessness, and the immune system becomes depressed. They exercised each day on the space station to stay as strong as possible and rode back to Earth in reclining seats to ease the jolt of gravity.

"They're very well conditioned, all things considered," said Dr. Terry Taddeo, a NASA flight surgeon. "I don't see that we're going to have any problem with them."

Besides ferrying up the space station's new crew, Discovery delivered 10,600 pounds of supplies and equipment during its 12-day mission. It is returning about 3,800 pounds of trash, discarded equipment and personal belongings of the station's former crew.

Thnew crew — Culbertson and Russian cosmonauts Vladimir Dezhurov and Mikhail Tyurin — will remain on the space station until December. NASA's next shuttle flight, by Endeavour, will be their ride home.

CBS News Space Consultant William Harwood has covered America's space program full time for more than 15 years, focusing on space shuttle operations, planetary exploration and astronomy. Based at the Kennedy Space Center in Florida, Harwood provides up-to-the-minute space reports for CBS News and regularly contributes to Spaceflight Now and The Washington Post.

© MMI, CBS Worldwide Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report