(AP) -- Space shuttle Atlantis thundered away on its final voyage to orbit Friday, hoisting an experienced crew of six and a full shipment of space station gear.
Atlantis sped through a perfectly clear afternoon sky, blazing a trail over the Atlantic before huge crowds eager to catch one of the few remaining shuttle launches.
Its destination is the International Space Station, which was soaring over the South Pacific at the time of liftoff. The shuttle should catch up with the orbiting complex and its six residents Sunday.
More than 40,000 guests - the biggest launch-day crowd in years - descended on the Kennedy Space Center, all of them eager to witness Atlantis' last launch. The shuttle obliged, roaring off the pad right on time.
"Good luck, godspeed and have a little fun up there," launch director Mike Leinbach told the astronauts just before liftoff. He said he was speaking on behalf of all those who have worked on Atlantis since construction began in 1980.
"Like you said, there are thousands of folks out there who have taken care of this bird for a long time," replied commander Kenneth Ham. "And if you don't mind, we'll take her out of the barn and make a few more laps around the planet."
The astronauts - all repeat space fliers and all men - couldn't resist a little humor before they got down to business. They showed up for their steak and cheeseburger breakfast wearing blue and black smoking jackets, white shirts and black bow ties.
The only concern during Friday's countdown involved a small ball bearing found in Atlantis' payload bay earlier this week. Engineers scrambled to determine the bearing likely came from a spacewalk camera, and cleared the launch with just minutes remaining.
The 12-day mission is the last one for Atlantis, the fourth in NASA's line of space shuttles. Only two flights remain after this one, by Discovery and Endeavour. NASA plans to end the 30-year program by the end of this year.
Atlantis rocketed into orbit for the first time in 1985. This will be its 32nd trip and the 132nd shuttle flight overall.
The shuttle is loaded with fresh batteries and a Russian-built compartment for the space station. The 20-foot-long module is crammed with food, laptop computers and other U.S. supplies.
Ham and his men will install the compartment on the space station, and carry out three spacewalks to replace six old batteries and hook up an antenna and other spare parts.
Launch spectators included late-night TV host David Letterman and dozens of Russians. About 150 Twittering guests were invited to Kennedy's media complex.
Matt Balan, 29, of Alexandria, Va., lost his network connection right at liftoff as he was trying to tweet. He finally got this message out a few minutes after the fact: "That was spectacular!!!!"
Even off-duty astronauts marveled at the sight of Atlantis rising one last time, snapping pictures with their cell phones. "That was an incredible launch," said Rick Mastracchio, who flew last month on Discovery.
President Barack Obama wants NASA to focus on getting astronauts to an asteroid by 2025 and into orbit around Mars by 2035. He canceled the previous administration's plan to return to the moon.
Friday's launch was NASA's fourth shuttle liftoff in six months. Now the pace will slow a bit. Discovery isn't due to fly until September, followed by Endeavour in November - at the earliest.
There's a chance that Atlantis could fly again after it returns to Earth on May 26. The shuttle will be prepped in case a rescue mission is needed for the last flight, by Endeavour. Assuming there's no emergency, Atlantis could be used for another supply run if the White House approves it, and that would close the shuttle program for good. Then the shuttles would head off to museums.
Immediately after watching Discovery soar, U.S. Sen. Bill Nelson, D-Fla., told The Associated Press that he's encouraging one more flight for Atlantis and noted: "There's a good chance the president will approve it." He flew Columbia into orbit in 1986.
Under the Obama plan, NASA astronauts will hitch rides to the space station on Russian Soyuz rockets for the near future.
NASA expects to keep the space station running through 2020.
Explore further: Italy's first female astronaut heads to ISS in Russian craft