Space shuttle Discovery's astronaut crew exchanges goodbye to aboard the International Space Station (ISS) in a teary eyed ceremony that replaced ISS astronaut Clay Anderson with Dan Tani. ISS commander Peggy Whitson hugs STS-120 astronaut Paolo Nespoli in the center.
Credit: NASA TV
It's crunch time for three astronauts aboard the International Space Station (ISS) as they prime their orbital laboratory for the planned December arrival of a new European-built module.
Commanded by veteran NASA spaceflyer Peggy Whitson, the station's Expedition 16 crew is trading its Thanksgiving holiday this month for a busy to-do list that includes no less than three spacewalks - the first of which begins Friday - and two critical moves of ISS hardware.
The spacewalks and hardware relocations must go smoothly, and NASA must find a way to trim about five days' worth of work from the Expedition 16 crew's schedule, if the shuttle Atlantis is to launch toward the ISS on Dec. 6 with the European Space Agency's (ESA) Columbus laboratory.
"Basically, we're taking our plan a couple weeks at a time now," Holly Ridings, NASA's lead ISS flight director for Expedition 16, told reporters Tuesday. "Our focus is to keep the [shuttle] launch in December and it'd be great if we can make the beginning of that window."
NASA has a slim window that runs from Dec. 6 to Dec. 13 in which to launch Atlantis to the ISS while the station's solar arrays and the Sun are in the optimum position to provide power during docked operations. If the shuttle misses the December window, it would launch no earlier than Jan. 2, mission managers have said.
Commanded by veteran shuttle flyer Stephen Frick, Atlantis' STS-122 astronaut crew will attach ESA's Columbus laboratory to the starboard side of Harmony, which serves as the central hub for European and Japanese modules at the ISS.
But before Frick and his six STS-122 crewmates can launch spaceward, Whitson and her own crew must move Harmony to its permanent spot outside the ISS.
Astronauts delivered the Italian-built Harmony node to the space station last week during NASA's STS-120 shuttle mission aboard Discovery, but the bus-sized compartment was attached to a temporary berth on the outpost's Unity module. Discovery's STS-120 crew, meanwhile, is set to land on Wednesday.
On Friday, Whitson and Malenchenko will step outside the ISS to prime a shuttle docking port for its move from the tip of the station's U.S. Destiny laboratory to the end of Harmony.
Tani will use the station's robotic arm to move the docking port move early Monday, then relocate the entire Harmony-docking port structure back to the front of Destiny on Wednesday. A pair of spacewalks, on Nov. 20 and 24, respectively, will fold Harmony and its docking port back into the ISS power and data grid.
Only then, Ridings said, will the Expedition 16 crew be ready to open Harmony and its shuttle docking port - known as Pressurized Mating Adapter-2 - for business as early as Nov. 26. Once Harmony is reopened, the station crew has about 15 days of work to perform, but only 10 days until the earliest opportunity for Atlantis to launch.
"The folks on the ground are very good about scheduling things out and making sure that we're not too overloaded," said NASA astronaut Clayton Anderon, a former Expedition 16 crewmember returning to Earth aboard Discovery. "I don't think it's going to be any trouble for them. They're going to knock it out and do great things."
Mission managers are now looking at which tasks can be culled from the Expedition 16 crew's schedule to allow the earliest launch attempt possible while still allowing the station astronauts adequate time for rest and relaxation.
"We need to give the crew an adequate rest time, we can't just run them seven days a week," said NASA's ISS Expedition 16 increment manager Pete Hasbrook. "And if that means going into the December window a little bit, we'll do that."
Even before launching to the ISS, Whitson and her crew decided to forego taking the traditional U.S. Thanksgiving holiday off on Nov. 22 if it would help ease their packed station construction schedule, Ridings added.
"Even preflight, the crew knew that this month of November was going to be very busy," Ridings said, adding that flight controllers will also be hard at work. "We'll have turkey in the control center and have a lot of fun, so we're looking forward to it."
- VIDEO: ISS Commander Peggy Whitson Takes Charge
- VIDEO: Discovery's STS-120 Astronaut Crew Speak Out
- SPACE.com VIDEO Interplayer: STS-120 Mission Brings 'Harmony' to ISS