KENNEDY SPACE CENTER, Fla.--After a cliff-hanger countdown, the space shuttle Atlantis thundered to life and majestically rocketed into history Friday, putting on one last sky show for spectators jamming area roads and beaches to witness NASA's 135th and final shuttle launch.
With commander Christopher Ferguson and pilot Douglas Hurley monitoring the computer-orchestrated countdown, Atlantis' three hydrogen-fueled main engines flashed to life at 120 millisecond intervals, followed 6.6 seconds later by ignition of the shuttle's twin solid fuel boosters at 11:29:04 a.m. EDT (GMT-4).
At that same instant, explosive charges in four massive bolts at the base of each booster detonated, freeing the 4.5-million-pound shuttle "stack" from its mobile launch platform.
Riding atop a torrent of flame jetting from the towering boosters, Atlantis instantly vaulted skyward on nearly 7 million pounds of thrust, trailing a churning cloud of dirty brown exhaust.
Accelerating to 100 mph--straight up--in just eight seconds, Atlantis climbed above the launch pad gantry, wheeled about and arced away on a northeasterly trajectory, disappearing from view in a deck of clouds as it set off after the International Space Station.
The weather was an issue all morning, with forecasters predicting a 70 percent chance of low clouds and rain that could cause a delay. Conditions improved as the morning wore on, but concern about rain showers near the space center resulted in an official "no-go" forecast for an emergency return to the Kennedy Space Center's shuttle runway.
After discussing the potential for rain and electrical activity, NASA's mission management team waived a flight rule requirement and Atlantis was cleared for launch.
"OK, Fergie, we're starting to feel pretty good here on the ground about this one today, so on behalf of the greatest team in the world, good luck to you and your crew on the final flight of this true American icon," Launch Director Mike Leinbach radioed a few moments earlier. "And so for the final time, Fergie, Doug, Sandy, and Rex, good luck, Godspeed, and have a little fun up there."
"Hey, thanks to you and your team, Mike and until the very end, you all made it look easy," Ferguson replied. "The shuttle's always going to be a reflection of what a great nation can do when it dares to be bold and commits to follow through.
"We're not ending the journey today, Mike, we're completing a chapter of a journey that will never end. You and the thousands of men and women who gave their hearts, souls, and their lives to the cause of exploration...let's light this fire one more time, Mike, and witness this nation at its best."
And so, running 2 minutes and 18 seconds behind schedule, Atlantis finally roared to life and headed for orbit for the last time, just 58 seconds before the end of the launch window.
Joining Ferguson and Hurley for the last shuttle flight were Sandra Magnus and flight engineer Rex Walheim, making up the first four-person shuttle crew since the program's sixth launch in 1983.
Without a second shuttle available for a rescue mission--Atlantis used NASA's final external tank and last set of boosters--mission managers limited the crew to four to make sure the astronauts can get home aboard Russian Soyuz spacecraft in case of a Columbia-class problem that might prevent a safe re-entry.
The early moments of the flight appeared normal and a camera mounted on the side of the external tank showed no obvious signs of any major problems as the shuttle climbed away. But as usual, analysts at the Johnson Space Center will spend the next few days reviewing imagery and radar data to make sure no debris struck Atlantis' fragile heat shield.
Debris poses the biggest threat during the first two minutes or so of flight, when the twin solid-fuel boosters are powering the shuttle out of the dense lower atmosphere. But that critical phase of flight went smoothly, and after two minutes and five seconds, the boosters were jettisoned, falling back to the Atlantic Ocean some 30 miles below.
Three-and-a-half minutes later, Atlantis rolled about its long axis to put the shuttle on top of the external tank to improve communications through a NASA satellite. Three minutes after that, the main engines shut down and Atlantis slipped into orbit for the 33rd and final time.
"Booster officer confirms main engine cutoff," reported mission control commentator Rob Navias. "For the last time, the space shuttle's main engines have fallen silent, as the shuttle slips into the final chapter of a storied 30-year adventure."
Ascent Flight Director Richard Jones passed along congratulations from the flight control team.
"Fergie, just wanted to say congratulations to you, Chunky, Sandy, and Rex, on a spectacular ascent," Jones said. "The ascent team is signing off right now, and we just wanted to wish you all of our best and that we are with you as you accomplish your historic flight. It's been a pleasure."
"Hey Richard, I tell you, the honor has been all ours," Ferguson replied. "We're some of the fortunate few who get a chance to see the world from this perspective. And I want to thank you guys. And boy, I cannot wait to hear the story, both A, coming out of the T-minute nine (minute) hold and B, at T-minus 31 seconds. I'm sure there were a few folks on the edge of their seats down there."
If all goes well, Ferguson will guide Atlantis to a docking at the space station's forward port at 11:10 a.m. Sunday. The next day, an Italian-built cargo module will be attached to the Earth-facing port of the forward Harmony module and the combined 10-member shuttle-station crew will begin a hectic week of work to move five tons of equipment and supplies into the lab complex.
The supplies packed into the Raffaello module are critical to the space station program. Two companies, Space Exploration Technologies--SpaceX--and Orbital Sciences Corp., are building unmanned cargo ships to take over from the shuttle after the fleet is retired with initial test flights expected later this year or early next.
Atlantis' mission was added to the shuttle manifest to deliver enough supplies to keep the station provisioned through 2012 as a hedge against development problems that might delay the commercial cargo ships.
"Some folks look at this flight and perhaps don't see the excitement because we don't have a piece of our assembly hardware going up," said Michael Suffredini, the space station program manager at the Johnson Space Center in Houston.
"But we've got the (cargo module) as full as we've ever had it, we've got the middeck. All of these supplies are going to be the lifeline to help us extend the period of time we can go on orbit before our commercial providers start flying regularly to ISS. That's critical to us, to give them the time they need to make sure their vehicles are ready to go fly, finish their development, and get their test fights behind them and then start servicing ISS."
With a reduced crew of four, only one spacewalk is planned during Atlantis' visit, a six-and-a-half-hour excursion by station flight engineers Ronald Garan and Michael Fossum. Their primary objectives are to move an experimental robotic refueling package from Atlantis to the station and to mount a failed ammonia coolant pump in the shuttle's cargo bay for return to Earth.
With an on-time launching Friday, NASA managers are expected to extend the mission one day to give the crew more time to pack up the cargo module with no-longer-needed equipment and trash. But a final decision will not be made until engineers make sure the shuttle's fuel cells have enough hydrogen and oxygen to support the extra day.
As of this writing, the flight plan calls for the astronauts to undock from the station around 2 a.m. on July 18. Landing back at the Kennedy Space Center is expected around 7 a.m. on July 20, the 42nd anniversary of Apollo 11's touchdown on the moon.
If the flight is extended, however, undocking would occur around 1:30 a.m. on July 19, setting up a predawn landing at the Florida spaceport around 6 a.m. on July 21.
For tens of thousands of past and present shuttle workers, including more than 3,000 expecting layoffs July 22, the traditional "wheels stopped" call from Ferguson will signal the end of an era, bringing the curtain down on three decades of shuttle operations.
"After the wheels have stopped and the displays go blank and the orbiter is unpowered for the final time...there will be a rush of emotion when we all finally realize that's it, that it's all over, the crowning jewel of our space program, the way we got back and forth from low-Earth orbit for 30 years...we'll realize that's all over," Ferguson said before launch. "That's going to take a little while to deal with."