With Twitterers in the front row, Atlantis blasts off

The supply run should keep the space station humming for years to come, and the shuttle astronauts in space through Thanksgiving.

Atlantis shot smoothly through a partly cloudy afternoon sky, to the delight of about 100 Twittering space enthusiasts who won front-row seats. It was NASA’s first launch “tweetup,’’ and the invitees splashed news - mostly tweeting “wow’’ and “amazing’’ about the liftoff - over countless cell phones and computers.

“We wish you good luck, godspeed, and we’ll see you back here just after Thanksgiving,’’ launch director Mike Leinbach told shuttle commander Charles Hobaugh right before liftoff.

Atlantis will reach the space station tomorrow. As the shuttle blasted off, the station was soaring 220 miles above the South Pacific.

“We’re excited to take this incredible vehicle for a ride and meet up with another incredible vehicle,’’ Hobaugh said.

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 are big enough to carry such large pieces.

The space agency expects to keep the space station flying until 2015, possibly 2020 if President 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 30,000 pounds 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, too late to be of any concern, said Bill Gerstenmaier, head of NASA’s space operations.

“What a great way to start this mission,’’ Gerstenmaier told reporters. He cautioned that 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.

This is NASA’s last shuttle flight of the year and one of six remaining. If all goes as planned, the six astronauts will return to Earth the day after Thanksgiving, bringing home a seventh crew member, Nicole Stott, who has been living at the space station since the end of August.