HOUSTON - With their launch date inching ever closer, six shuttle astronauts are eagerly looking forward to rocketing toward the International Space Station (ISS) with a set of solar arrays in tow.
Atlantis' STS-115 astronaut crew is slated to launch Aug. 27 on a complex mission to resume construction of the half-built ISS.
"This is a very challenging and complex assembly mission with a very aggressive timeline, especially over the first five to seven days," Atlantis shuttle commander Brent Jett, who helped deliver the station's first solar arrays during NASA's STS-97 mission in 2000, told reporters here at NASA's Johnson Space Center Friday. "This crew is ready to execute our part of that mission.
Accompanying Jett aboard Atlantis will be STS-115 pilot Chris Ferguson and mission specialists Joseph Tanner (also an STS-97 veteran), Daniel Burbank, Heidemarie Stefanyshyn-Piper and Steven MacLean of the Canadian Space Agency.
The astronauts are preparing to deliver a 17.5-ton truss segment to the ISS along with two massive solar arrays that will ultimately span about 240 feet (73 meters) from end to end once deployed. The truss will be the first major addition to the ISS since construction flights were tabled following to the 2003 Columbia accident.
"This, I think, really signifies the beginning of the culmination of the space station," said Ferguson, who is making his first spaceflight during the STS-115 mission. "You'll be seeing a series of assembly flights that have been unparalleled in their complexity and their detail, and their timelines."
A busy flight
With three spacewalks, two shuttle heat shield inspections, some cargo delivery and the restart of ISS construction ahead of them, Atlantis' STS-115 astronauts have a lot on their plate.
The orbital inspections, first used in NASA's two post-Columbia test flights, are now standard activities to ensure an orbiter's protective tiles and wing edge panels have not been damaged by launch debris - the problem that doomed Columbia.
"When we started training for this mission about four and a half years ago, robotics was a relatively small operation that was going to take just a few hours, and then it was going to be over," said Ferguson, who will help inspect Atlantis' heat shield in orbit. "Now it seems like robotics operations with the arm and the onboard [inspection] boom sensor system are going to take up the better part of Flight Day 2 and an entire day after we undock."
Just after arriving at the ISS on Flight Day 3, Atlantis astronauts will use the shuttle's arm to grapple their Port 3/Port 4 truss and solar array payload and swivel it out of the cargo bay for later installation at the end of the station's left - or port - side.
Two back-to-back spacewalks by the STS-115 mission specialists are scheduled to ready the new solar arrays for deployment once the truss is mated to the ISS. One last spacewalk, after the arrays are deployed, will finalize the installation.
"It's definitely a very full mission, but one we're very, very eager to get started with," said Stefanyshyn-Piper, who like Ferguson is making her first spaceflight during the flight.
Bigger, better station
Atlantis' STS-115 mission will mark the first of at least 15 planned shuttle-ISS construction flights since late 2002.
"It will be a pleasure to leave the station in a much different configuration than when we first arrived," Ferguson said, adding that he hopes Atlantis will have enough fuel to circle the station - for some parting photographs - after undocking. "I'd like to think we are truly back on step."
Of the upcoming construction missions, the next few will be dedicated to adding three additional solar arrays to the station, where they will join a fourth already onboard. Among the remaining ISS segments to fly are two orbital laboratories, Europe's Columbus module and Japan's Kibo component, that will nearly double the station's habitable area from its current size - about that of a three-bedroom home - to the equivalent of a five-bedroom dwelling.
"This is an exciting flight and this is an exciting time," Ferguson said. "I think we're all proud to be a part of it."
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