Atlantis Back Home From Construction Site

The space shuttle Atlantis landed Thursday after a 12-day mission that put NASA back in the space station construction business.

“Congratulations on return to assembly,” said flight controller Tony Antonelli in Houston to shuttle commander Brent Jett.

“It’s great to be home,” Jett said after his walk-around inspection of the spacecraft, which NASA officials described as “very clean.”

Atlantis landed at 3:21 a.m. PDT, sending its signature pair of sonic booms over the marshes and grasslands of central Florida. As it swept out of the dark sky, it executed a series of steep, banking turns to bleed off some of its speed.

Far above, the crew of the International Space Station watched the fiery plasma stream spewing from the spacecraft’s superheated wings. American astronaut Jeff Williams described “spectacular lightning flashes” near the craft and a “very bright” contrail.

NASA managers said the success of the mission makes them more optimistic that they will be able to finish construction of the space station by the time the shuttle is retired in 2010.

“We’re back into a more normal operational tempo now,” said NASA Administrator Michael D. Griffin. “It’s obvious to me that we are rebuilding the momentum we had” before the Columbia accident in 2003.

In what was described as one of the most arduous missions in the 25-year history of the shuttle program, the crew of Atlantis installed a 17.5-ton truss and a new set of solar arrays on the space station during three spacewalks. When the arrays are wired into the station’s grid, they will double the amount of power produced by the station.

“We’re happy to get all the mission objectives accomplished,” Jett said during a news conference several hours after the landing.

Pilot Chris Ferguson said he felt “a feeling of pride and awe” when he looked back at the station after undocking and saw the truss and the solar arrays in place.

A series of incidents afflicted the two-week mission, beginning at the launching pad with a lightning strike -- believed to be the largest ever to hit the site -- on the protective mast above the shuttle.

The strike didn’t damage the spacecraft, but it did force a launch delay. Another delay occurred when Tropical Storm Ernesto bore down on the Florida coast.

The most anxiety came near the end of the mission when astronauts spotted a piece of debris out a window at about the same time sensors in one of the wings recorded several possible impacts.

The incident evoked memories of Columbia, which was damaged during launch when a piece of insulating foam from its external fuel tank hit the forward edge of the left wing.

All seven crew members died when Columbia broke up on reentry.

NASA safety engineers were relieved when they were able to link the sensor readings on Atlantis to the normal shuddering of the engines when the crew test-fired them after undocking from the space station.

The debris, officials surmised, was probably a 2-by-5-inch plastic spacer placed between the heat-resistant tiles during installation.

One of the red shims was seen sticking out from the underside of the shuttle after launch. A final inspection the day before landing showed it was gone.

In contrast, the installation work on the space station went smoothly and more quickly than expected. The only glitches were the loss of a couple of bolts that floated away, joining the estimated 13,000 pieces of space junk orbiting Earth.

Managers said the mission was so successful that they are considering moving up the next launch to early December.

Griffin also said the foam on the external fuel tank performed very well, and engineers may call off plans for further redesigns. Safety officers have been concerned about the danger of foam coming off an area of the tank called the ice/frost ramp.

“We are going to look closely at whether we need new ice/frost ramps,” Griffin said.

john.johnson@latimes.com