Space shuttle Discovery and its crew of six returned to Earth through thick clouds yesterday, ending an impressive mission that put NASA's space programme back on a solid, safer course.
Discovery landed at Kennedy Space Centre at 9:14 am (1314 GMT) in only the second shuttle flight since the 2003 Columbia disaster killed seven astronauts.
"Welcome back, Discovery, and congratulations on a great mission," Mission Control told shuttle commander Steven Lindsey after Discovery rolled to a stop.
"It was a great mission, a really great mission, and enjoyed the entry and the landing," Lindsey replied.
The smooth landing was sure to leave NASA officials jubilant, after conquering the chronic threat of foam chunks that break off the external fuel tank during launch still a problem, but not a serious one in this mission.
The shuttle came in from the south, swooping over the Pacific, Mexico's Yucatan Peninsula, the Gulf of Mexico and across Florida to cap a 8.53-million-kilometre journey that began on July 4.
A last-minute build-up of clouds led NASA to switch the shuttle's direction for landing. By the time Discovery approached, it was so cloudy that Lindsey couldn't spot the runway until about a minute before landing.
A couple of minutes out, NASA made a racket to keep birds out of the way of the approaching spacecraft. Car horns blared, and the sound of gunshots and firecrackers erupted.
At touchdown, shouts and whistles came from the few hundred astronauts' relatives and space centre workers at the runway. "It's exciting to see the shuttle back," said astronaut Scott Kelly, the identical twin brother of Discovery's co-pilot, Mark Kelly. "We're back on track with maybe flying the shuttle regularly here starting again in August."
Atlantis is up next with a crew poised to carry out assembly of the international space station, a task put on the back burner after Columbia.
NASA officials had been certain going into yesterday's landing that Discovery's heat shield was intact and capable of protecting the spaceship during the fiery re-entry.
Repeated inspections of the ship's thermal skin in orbit had given everyone confidence. Unlike Discovery's flight a year ago, the external fuel tank shed little foam insulation during lift-off. That flight was the shuttle's first after a chunk of falling foam doomed Columbia and its crew.
Discovery sported a new, tougher type of landing gear tire for improving safety. In another shuttle first, an on-board GPS receiver helped guide the shuttle down to the 4.8-kilometer landing strip.
"It was beautiful," Lindsey told Mission Control right before getting off the shuttle. "We could see the bright orange glow above and I could see the Earth moving below and it was just spectacular. We actually also saw the moon through the plasma (scorching gases), so it was a great entry and a great landing."
The shuttle carried up seven astronauts, but departed the space station on Saturday with six Lindsey, co-pilot Kelly, Michael Fossum, Piers Sellers, Lisa Nowak and Stephanie Wilson. German astronaut Thomas Reiter of the European Space Agency was left behind for a half-year stay, joining two other men there and boosting the station's crew size to three.
The Discovery crew conducted three spacewalks, one of them to test shuttle patching techniques, and used a 30-metre inspection crane to check the shuttle's entire thermal armour for any damage from launch or orbital debris.
The astronauts also demonstrated that the boom could function as a work platform for spacewalkers and delivered several thousand kilograms of supplies to the space station, still in need of restocking because of the 2 1/2-year grounding of the shuttle fleet after Columbia's demise.
By fixing a broken rail car on the outside of the space station, the astronauts paved the way for space station construction to resume in earnest with the next shuttle flight.
Atlantis is scheduled to blast off as early as August 27. Unlike Discovery's missions, which focused primarily on the flight test aspects, the Atlantis crew will haul up a major space station piece a building-block beam and attach it to the orbiting outpost.
The station is just half finished, eight years after the first piece went up. NASA wants it completed by the time the three remaining shuttles are retired in 2010 to make way for a new spaceship capable of carrying astronauts to the moon.
Source: China Daily