In clear but frigid weather, Russian engineers hauled a Soyuz rocket to the launch pad Friday, setting the stage for launch Sunday on a six-hour flight to ferry a veteran Russian cosmonaut, a NASA shuttle pilot and a European rookie to the International Space Station, boosting the lab's crew back to six and kicking off a busy winter of research and assembly work.
Soyuz TMA-15M commander Anton Shkaplerov, flanked by flight engineer Samantha Cristoforetti and NASA astronaut Terry Virts, are scheduled for liftoff from complex 31 at the Baikonur Cosmodrome in Kazakhstan at 4:01:14 p.m. EST (GMT-5; 3:01 a.m. Monday local time), roughly the moment Earth's rotation moves the pad into the plane of the station's orbit.
Soyuz flights are more commonly launched from pad 1, the same firing stand used by Yuri Gagarin at the dawn of the space age, but required maintenance prompted the Russians to use complex 31 for the TMA-15M launch, the first use of the facility for a piloted Soyuz flight since a station-bound crew took off from there in October 2012.
If all goes well, Shkaplerov and his crewmates will oversee an autonomous four-orbit rendezvous with the space station, moving in for docking at the Earth-facing Rassvet module Sunday around 9:53 p.m. Standing by to welcome them aboard will be Expedition 42 commander Barry "Butch" Wilmore, Alexander Samokutyaev and Elena Serova, who were launched to the outpost September 25.
Wilmore and company have had the station to themselves since Nov. 9 when Maxim Suraev, European Space Agency astronaut Alexander Gerst and NASA astronaut Reid Wiseman departed and returned to Earth. With the arrival of the TMA-15M crew, the focus of station operations will shift back to a full slate of research activity and a series of spacewalks next year to prepare the lab for dockings by new commercial crew ferry craft now under development in the United States.
Serova is the first female cosmonaut assigned to a long-duration flight aboard the station. A half-dozen female NASA astronauts have lived aboard the complex during the 14 years it has been staffed, but Cristoforetti is the first woman assigned to a long-duration flight by the European Space Agency.
A veteran fighter pilot and a captain in the Italian air force, Cristoforetti's resume reads like a roadmap to orbit, with a master's degree in mechanical engineering, expertise in aerospace propulsion technology, and more than 500 hours flying time in a variety of military aircraft, including the AM-X ground-attack fighter-bomber. During a pre-flight news conference, she described herself as "somebody who looks forward to a challenge."
"Learning how to be a flight engineer on the Soyuz was extremely gratifying," she said. "It kind of brought me back a little bit to flying a new airplane, where you have to learn, get familiar with all the systems, the procedures and what you do in a nominal case, what you do if something goes wrong. I've always been trained as a single-seat aircraft pilot so it was interesting to learn how to be a three-seater where you have a crew you have to work with. A very different mindset. Fun!"
Virts served as pilot of the shuttle Endeavour during a 2010 space station assembly mission. Like Cristoforetti, he is a veteran Air Force test pilot with 45 combat missions to his credit flying F-16 fighters. But in his case, moving from the shuttle to the Soyuz meant adapting to a smaller crew -- and a smaller, more nimble spacecraft.
"I'm looking forward to flying a different spaceship," he told CBS News. "I'm a test pilot, and I like flying different airplanes and different vehicles, and so it's going to be fun to be in a Soyuz. It flies differently than the shuttle, it's much smaller and it just moves quicker. The flying qualities are different. As a test pilot, I'm looking forward to seeing that."
Asked how he viewed the risk of flying on the Russian spacecraft, Virts said he had no concerns.
"The Soyuz has a great reliability record," he said. "It's been flying since the 1960s, and they've been flying it safely for decades. So I have a lot of confidence. I've gotten to meet a lot of the Russian builders, I've been to the factories where they build it, I've actually seen our vehicle and been inside of it. We're very confident."
Asked what was the most challenging aspect of training for launch on a Soyuz, Shkaplerov joked about falling asleep during simulations "because Samantha had prepared so well, we had nothing to do. As a flight engineer, she will do everything, so we just had to take it easy and relax!
"But seriously, for some of us flying for the second time, the hardest thing was getting to be close with our fellow crew members," he said. "We had really not met each other before beginning the training. Then meeting for the first time and learning how to work together and how to live together as one unit as we will be on the space station for six months, that was the challenge, and I think we did it very well."
Virts said the most difficult aspect of his training for launch was learning to speak Russian. Cristoforetti already spoke Russian, "so that wasn't too hard," she said.
"For me, I guess, the greatest challenge was probably the spacewalk training," she said. "We don't have suits in a small size to fit me properly. So that does present a little bit of an additional challenge. ... But on the other hand, as always happens in life, the hardest thing, once you master it, is the one that's the most gratifying."
The Expedition 42 crew faces a busy time in orbit with multiple spacewalks next year to equip the U.S. section of the station with two docking adapters that will allow commercial crew ships being built by Boeing and SpaceX to dock at the outpost. Virts and Wilmore plan to carry out three spacewalks in late January and early February to make preparations for installation of the docking rings.
Along with spacewalk preparations, Virts will be focused on research, both hands on and remotely monitoring external payloads.
"There is lots and lots of science, roughy 170 American experiments and over 70 international ones," he said during a news conference. "I really like astronomy, and there's a big instrument on the outside of the station called AMS, Alpha Magnetic Spectrometer. There's also an instrument on the Japanese segment called MAXI. These instruments are looking for anti-matter and super-high-energy particles that come into Earth from all around the galaxy and really beyond the galaxy.
"I think right now we're in the process of making some pretty amazing discoveries about what the universe is made out of and what exactly is out there. The more you find out about the universe, you realize there are things you didn't know. But that's astronomy."
Virts also will serve as a test subject for medical research on the effects of weightlessness on human physiology ranging from bone loss to muscle degradation and vision problems. He said about 30 percent of the astronauts who flew short-duration shuttle missions came home with degraded vision that eventually returned to normal, or near normal.
"Now we're finding that 60 percent of long duration fliers have vision (problems) and some of those don't correct, I mean they can still see, but you have degraded vision," he said. "So one of the main experiments I'm doing is going to be a pretty comprehensive study of vision. I'll be doing ultrasound on my eyes, an OCT scan (optical coherence tomography), a fundascope, several different cameras looking inside the eye, some ultrasound of my brain and heart and pressure and blood flow into the eye.
"So there's a very intense focus on that problem right now, astronaut vision," he said. "So far, knock on wood, it hasn't been anything terrible, but it is something we're noticing and it's not something we want for the future."
Virts also will work with Cristoforetti on an ESA experiment to study lung function and health in weightlessness.
"That's an extremely complex setup where we're going to be breathing a special gas mixture," she said. "The idea there is to study gas exchange in the lungs, a very new field, very interesting for fundamental science, to understand better how that works, how your lungs work."
The research will help scientists better understand how reduced pressure and exposure to floating particulates inside a spacecraft might affect lung health.
"That's going to be very interesting because it's going to be the first experiment that actually takes place in the airlock at a reduced pressure," Cristoforetti said. "Certainly a very interesting setup."
But it won't be all work and no play. All three TMA-15 crew members said they were especially looking forward to off-duty time and a chance to take in the view from 260 miles up. During his 2010 shuttle flight, Virts' crew installed the seven-window cupola compartment that offers a picture-window view of Earth.
"Looking at Earth is the most powerful drug you can imagine," Virts said. "You just can't get enough of it, and that's kind of all you want to do. Not only Earth, but also looking out into space. I'm sure I'll be spending my time looking at everything. And there are so many amazing things to see, thunderstorms in the Amazon and central Africa, you just can't get enough of that, especially at dawn, because then you can see both the clouds and the lightning."
In addition to taking in the view, "I also want to get to be good at moving and flying and floating around in space and just living in space," he said. "It's different in weightlessness, it's not like anything you've ever experienced on Earth. On my shuttle flight, the learning curve was still going uphill, and I'm looking forward to having more time and actually getting good at being a person who lives in space."
Said Shkaplerov: "Everyone knows being an astronaut is a dangerous profession, but it is definitely very interesting, it is so worth it. Everything becomes worth it once you're able to see the Earth from the window of the space station."