CAPE CANAVERAL, Fla. - With 100 Internet-savvy NASA fans cheering on the shuttle and churning out constant Twitter updates, Atlantis sailed smoothly into orbit Monday with six astronauts and a full load of spare parts for the International Space Station.
The supply run should keep the space station humming for years to come, and the shuttle astronauts in space for 11 days.
Also on board are 24 willow saplings for a Canadian experiment to study how gravity affects the formation of different kinds of wood.
The experiment is led by Prof. Rodney Savidge of the University of New Brunswick and funded by the Canadian Space Agency. Canadian astronaut Robert Thirsk will manage the experiment on the space station.
Atlantis was clearly visible as it shot through thin afternoon clouds, to the delight of Twittering space enthusiasts who won front-row seats to the launch. The contest winners splashed news - mostly tweeting "wow" and "amazing" about the liftoff - over countless cellphones and computers in 140 characters or less.
"What's exciting to me is that they've captured the spirit and the excitement that we all feel, and they were able to capture it in a very few number of characters," NASA space operations chief Bill Gerstenmaier said with a chuckle. "They're amazing, little, short statements about what they felt."
Atlantis will reach the space station Wednesday. As the shuttle blasted off, the station was soaring 350 kilometres above the South Pacific. Launch director Mike Leinbach wished the astronauts good luck.
"We're excited to take this incredible vehicle for a ride and meet up with another incredible vehicle," Hobaugh replied.
NASA wants to stockpile as many pumps, tanks, gyroscopes and other oversize equipment as possible at the space station, before the three remaining shuttles retire next fall. None of the other visiting spacecraft is big enough to carry so many large pieces.
The space agency expects to keep the space station flying until 2015, possibly 2020 if President Barack Obama gives the go-ahead.
During their 11-day flight, Hobaugh and his crew - including the first orthopedic surgeon in space, Dr. Robert Satcher Jr. - will unload the nearly 13,600 kilograms of equipment and experiments. Most of the gear will be attached to the outside of the space station on storage platforms.
Three spacewalks will be conducted beginning Thursday to hook everything up and get a jump on the next shuttle flight.
The launch seemed to go perfectly. Only three small pieces of foam insulation were spotted coming off the fuel tank, and it was not a concern, said Bill Gerstenmaier, head of NASA's space operations.
"What a great way to start this mission," Gerstenmaier told reporters. He cautioned the flight ahead was tough and "we need to stay focused."
While NASA officials were pleased, the Twittering invitees were downright ecstatic. They were among the first to sign up online last month for the opportunity to see a launch up close, and filed Twitter updates practically nonstop.
"The wifi and cellular networks are so bogged down with excited tweets that it is hard to get messages out," posted Laura Burns, 33, a Maryland software systems engineer.
NASA estimates the 100 tweeters, or tweeps as they're called, have a following of more than 150,000. The space agency sees it as a beneficial outreach program, especially as the shuttle program winds down and the future remains murky.
Obama has yet to chart a course for American astronauts, beyond the shuttle and station. A moon rocket under development is supposed to replace the shuttle, but the lunar exploration program is in jeopardy.
This is NASA's last shuttle flight of the year and one of only six remaining. "Five to go ... it's starting to hit home, I have to admit," Leinbach said.
If all goes as planned, Atlantis' six spacemen will return to Earth the day after the American harvest holiday of Thanksgiving, bringing home a seventh astronaut, Nicole Stott, who has been living at the space station since the end of August.
The astronauts will have to forgo the usual Thanksgiving fare. NASA did not pack any special dinners aboard Atlantis. Hobaugh, the commander, didn't want any.
If the astronauts want poultry on Thanksgiving, they'll have to settle for turkey tetrazzini in rehydratable pouches or thermostabilized chicken fajitas. There's also plenty of barbecued beef brisket.
-With files from The Canadian Press.