The countdown clock is ticking toward a Sunday launch of the space shuttle Atlantis, on a mission to resume construction of the international space station after a 3½-year gap.
“We have a saying back in Texas, ‘It’s time to walk the walk,”’ Atlantis commander Brent Jett said Thursday as the mission's six astronauts arrived from Houston by training jet. “We are ready for the challenge. ... All we need is a little good weather on Sunday and we’ll be out of here.”
And good weather appeared likely. There was only a 30 percent chance it would prevent a liftoff around 4:30 p.m. ET Sunday. If the launch is delayed that day, for weather or any other reason, the space agency would keep trying over several more days.
The weather forecast actually improves on Monday and Tuesday as a high pressure ridge moves north. Forecasters were keeping an eye on a tropical wave that could develop into a tropical depression by the Lesser Antilles, said Kathy Winters, shuttle weather officer.
Launch managers foresaw no technical problems, said Steve Payne, NASA test director. “Atlantis is in excellent shape,” he said.
Getting back to construction
This mission is the start of a renewed effort to finish building the international space station before the cargo-carrying shuttles are retired in 2010.
Construction has been delayed since the Columbia accident in 2003, which killed seven astronauts. The two space missions since that time have been focused on testing safety improvements on the spacecraft.
Atlantis will carry a 17½-ton addition, costing $372 million, from which two solar wings will be opened up. The solar arrays eventually will provide a quarter of the space station’s power when it is finished.
The addition arrived at the Kennedy Space Center almost seven years ago, said payload manager Robbie Ashley. “It has been a long time coming,” he said.
Atlantis’ crew, who have been training together for more than four years, includes pilot Chris Ferguson and mission specialists Joe Tanner, Dan Burbank, Heidemarie Piper and Steve MacLean of the Canadian Space Agency. Crew members will take three spacewalks during the 11-day mission.
“Walking out to the pad on Sunday will be much like walking into an Olympic stadium for your athletic event,” said MacLean, who was on the Canadian National Gymnastics team three decades ago. “With a team like this ... I promise you we’ll bring home a gold medal.”
During the buildup to the launch, NASA officials said Atlantis' mission would kick off the most complex phase of space station construction.
“This has been described ... as one of the most difficult tasks ever attempted by humans and I’m here to tell you that it seems like it’s going to be that hard,” said Mike Suffredini, NASA station program manager. “This has never been done before, the creation of a spacecraft in space.”
Dealing with a 2010 deadline
As if all that weren't pressure enough, NASA is working with a firm deadline of 2010 to finish the job. The agency's administrator, Mike Griffin, says the cargo-carrying shuttle fleet will have to be retired by then to allow for the development of new spaceships that would carry Americans back to the moon by 2020.
In a round of pre-launch interviews, Jett told reporters that overcoming the challenges of completing the space station will help NASA deal with the longer-term challenges as well. “It’s preparing us as an agency to take the next step back to the moon for a permanent outpost or onto Mars,” he said.
Jett said his crew will set the tone for the next four years of construction, since each mission to the station builds off the next. “Like a sports team, an athletic event, you want to get off to a good start,” Jett said. “If we have major problems ... that can’t be resolved, it’s going to change those missions significantly.”
Jett and Tanner in particular know what it’s like to run into problems.
They were members of a crew in 2000 with similar construction tasks: bringing an addition to the space station and unfurling from it two wings of solar panels, each the length of about a third of a football field. During the 2000 mission, the solar panels unexpectedly stuck to each other while they were being deployed, but the problem was fixed during the mission.
This time around, NASA has devised a new method to keep the wings from sticking together. The solar panels delivered on Atlantis eventually will generate about a quarter of the space station’s power when the structure is finished.
The Atlantis crew has one of the most jam-packed schedules ever devised for a shuttle mission. They not only have to perform three complicated, highly choreographed spacewalks to install the addition during their 11 days in space, but they also must complete inspection tasks that were implemented after the Columbia disaster to look for any damage to the shuttle’s thermal skin.
After docking with the space station, the 45-foot-long (14-meter-long) addition will be lifted by robotic arm from the shuttle’s payload bay and handed off to the space station’s robotic arm. The next day, Tanner and Piper will go out on the first spacewalk, followed a day later by a second spacewalk by Burbank and MacLean. The next day, the solar wings will be opened, and the following day, Tanner and Piper will go on a final spacewalk.
The opportunities for the liftoff of Atlantis occur daily from Sunday through Sept. 13 — dates based on calculations necessary to get the shuttle to the space station in a set time period. But NASA hopes to get the shuttle up before Sept. 7 so the mission doesn’t interfere with a trip to the space station by a Russian Soyuz vehicle in mid-September.
The Atlantis astronauts have trained together 4½ years, making them the longest-trained crew ever. Their mission originally was set for mid-2003 but was delayed because of the Columbia disaster.
“We’ve managed to hang together,” Ferguson said. “I think we’re going to do it, barring a hurricane.”