NASA hopes to find there was no damage done to the shuttle Discovery during Tuesday's launch.

But officials said an object that may have been a small piece of thermal tile appeared to break off from the Discovery's belly during liftoff. It came off from around a particularly vulnerable spot, near the doors to the compartment containing the nose landing gear.

John Shannon, NASA's flight operations manager, said a large object -- maybe a piece of foam insulation -- seemed to fly off from the giant external fuel tank but did not hit the shuttle itself.

Deputy shuttle program manager Wayne Hale said it will take some time to examine all the images from more than 100 cameras covering the launch. At a noon EDT news conference he said that early reports from video and radar reviewed showed no debris.

NASA has been especially concerned about debris since a chunk of foam from the external fuel tank punched a hole in the wing of the shuttle Columbia, leading to a re-entry disaster in 2003 that destroyed the craft and killed seven astronauts.

'America's New Journey'

Discovery lifted off on time Tuesday, "beginning America's new journey to the moon, Mars and beyond," in the words of the mission announcer.

About two minutes after leaving pad 39-B, the solid rocket boosters separated from the craft as planned as the three main engines carried the shuttle to orbit.

At Tuesday's news conference, NASA Administrator Michael Griffin talked about the power and majesty of the launch, as well as the professionalism and determination of everyone involved in restarting the shuttle program.

"They have worked as hard as any team in NASA history," he said.

Discovery rose into the sky at 10:39 a.m. EDT. Soon after, the normal jettisoning of the solid rocket boosters took place. Minutes later, the external fuel tank separated. For the first time, NASA provided live video of the event from a camera on the tank.

NASA said the craft was on track to reach the proper altitude and would not need major adjustments. During the news conference, the payload bay doors on the shuttle were opened and the crew began its in-orbit tasks such as testing the robotic arm.

Two chase planes and more than 100 cameras recorded the launch from every possible angle to catch any sign of flying debris.

Hale said that everything appeared fine, though "one of hundreds" of temperature sensors was erratic.

He also said that NASA would wait until after the mission is complete to discuss whether the upcoming flight of Atlantis would also be allowed to go ahead with only three working sensors, as Discovery would have been.

First Lady Laura Bush, relatives of the Discovery and Columbia crews and other dignitaries were among the observers attending the launch.

Landing is expected at 5:46 a.m. EDT, Aug. 7, at the Kennedy Space Center.

Countdown Goes Smoothly

During overnight refueling, a pesky fuel sensor showed no signs of the malfunction that scrubbed the July 13 attempt at the first launch since Columbia ripped apart two-and-a-half years ago.

At 7:45 a.m. EDT Cmdr. Eileen Collins was on board, and the rest of the crew soon followed, assisted into their seats by ground crew members. They then worked through pre-flight checklists, including communications tests.

Just before 9 a.m. EDT, the white-suited "closeout" crew that helps astronauts get on board reported that all "non-flight" items had been removed from the crew cabin, and then the outer hatch was closed.

At 9:47 a.m. EDT, the official countdown clock reached 9 minutes and went into a planned 45-minute hold.

Earlier, crew members wore Hawaiian shirts during breakfast.

Bush Reacts

President George W. Bush was glued to his television as NASA launched the shuttle.

Bush issued a statement praising NASA and wishing the crew "a safe and successful mission."

The president said the nation's space program "is a source of great national pride" and called the flight "an essential step" in "continuing to lead the world" in space science and exploration.

His spokesman said the president watched -- and applauded -- from his private dining room as Discovery took flight.

Mission Plan

The planned mission is to take a crew of seven to the international space station, where it will install a new gyroscope and provide supplies, among other tasks.

Docking with the space station is scheduled for Thursday, the third day of the mission.

They will also test methods for inspecting and repairing damage in flight.

There are three spacewalks planned during the mission.

Discovery was outfitted with a redesigned fuel tank and has dozens of motion and temperature sensors embedded in the wings to detect any blows from fuel-tank foam or other debris.