A Russian Soyuz spacecraft is poised to launch toward the International Space Station Tuesday to deliver three new members of the orbiting laboratory's multi-cultural crew.

The Soyuz TMA-19 spacecraft is set to lift off at 5:35 p.m. EDT (2135 GMT) from Baikonur Cosmodrome, Kazakhstan in Central Asia carrying two American astronauts and one veteran Russian cosmonaut toward the the space station.

"The station has grown magnificently. You can't believe it," said cosmonaut Fyodor Yurchikhin, who is returning to the space station on the Soyuz for the first time since 2007, in a prelaunch press conference.

Yurchikhin will launch alongside NASA astronauts Douglas Wheelock and Shannon Walker to join three other crewmates already aboard the International Space Station for the joint Expedition 24 mission at the nearly complete orbiting lab.

It will actually be 3:35 a.m. local time on June 16 when Yurchikhin and his crewmates blast off, placing their liftoff on the 47th anniversary of the launch of the first woman in space – cosmonaut Valentina Tereshkova – in 1963.

"It's an honor to launch on her date, as well," Walker said.

Over the next six months, the astronauts and cosmonaut expect to perform several spacewalks to maintain the $100 billion space station. They also expect to host NASA's two final space shuttle missions – currently scheduled for mid-September and late November – before the U.S. space agency retires the shuttles for good.

"It's a big change in our program...but change is not always bad," Wheelock told reporters.

And while the new station astronauts may be present for the end of space shuttle era, their mission to prime the outpost for another decade in orbit is also exciting, he added.

"It's actually bittersweet to see the shuttle go but it's really an exciting time as well," Wheelock said. "We're also going to be the first increment to really go to full utilization of the space station as an orbiting laboratory."

Once the space shuttles retire, NASA will rely on Russian Soyuz vehicles to ferry American astronauts to and from the space station until new commercial spacecraft are available under a new space plan announced this year by U.S. President Barack Obama.

Space station crew spotlight

Yurchikhin, 51, is a veteran cosmonaut with Russia's Federal Space Agency making his third trip to the space station. He commanded the orbiting laboratory for six months in 2007 during the Expedition 17 mission and flew on NASA's STS-112 shuttle flight to the station in 2002. For this mission, he is commanding the Soyuz treks to and from the orbiting laboratory.

"It should be very great Expedition, I hope, like any Expedition on space station," Yurchikhin said in a NASA interview.

Yurchikhin is a mechanical engineer with a Ph.D. in economics who joined the Russian Space Corporation (RSC) Energia's cosmonaut corps in 1997 following a series of flight controller and engineering jobs. He served as the lead engineer for the joint Shuttle-Mir space station and NASA-Mir programs, ultimately flying on the shuttle Atlantis in 2002 before his first space station flight.

He and wife Larisa have two daughters. Yurchikhin is from Batumi in the Autonomous Republic of Ajara in Georgia.

"Wheels" in space

Like Yurchikhin, Wheelock – who goes by the call sign "Wheels" – is making a return to the International Space Station.

A colonel in the U.S. Army, Wheelock last flew to the space station during a 15-day mission aboard the shuttle Discovery in late 2007. This flight, however, he is ready for the long haul and has been posting updates and photos from his mission on Twitter under the name Astro_Wheels.

"Our chariot awaits! The Soyuz TMA-19 rocket standing ready at the launch pad," he wrote on Sunday after the rocket was hoisted into launch position.

Wheels is expecting to pull double-duty aboard the space station, first as a flight engineer with the Expedition 24 crew and later in command of the station's Expedition 25 mission in about three months. He has been working hard to hone his leadership skills.

"So that's my primary task, and I'm very much looking forward to flying aboard this marvelous machine," Wheelock said in a NASA interview.

Wheelock, 50, is from Windsor, New York and is veteran test pilot and spacewalker who joined NASA's astronaut corps in 1998. This is his second space mission.

Houston's hometown astronaut

Walker, 45, is the only rookie on this Soyuz launch, but she's no stranger to human spaceflight.

She was born and raised in Houston – the Texas-home to NASA's space station and space shuttle mission control centers – and is the first-ever Houston native astronaut to earn her spaceflight wings as a professional NASA spaceflyer.

Walker joined NASA's ranks in 1987 as a space shuttle flight engineer after earning a doctorate in physics from Rice University. She was accepted to the astronaut corps in 2004 and spent much of her time since learning how to help fly Russia's Soyuz spacecraft.

"Only a handful of us have been trained as the co-pilots on the Soyuz, and it's quite an extensive training process. I've spent the better part of the last three years over in Russia working with my Russian colleagues and my Russian instructors to learn how to be the co-pilot," Walker said in a NASA interview. "So it's quite an endeavor."

And Walker is not the only member of her family to fly in space. Her husband is Andrew Thomas, a veteran NASA astronaut who has flown three short-duration missions on space shuttles and one months-long trip to Russia's Mir space station.

Busy time in space

Yurchikhin, Wheelock and Walker are launching to the station during a busy time for the orbiting lab.

Earlier this month, June 2, the station's former Expedition 23 crew returned to Earth in a picture-perfect landing on the steppes of Kazakhstan. Since then, the station's crew size has been at half-strength.

But that will change Thursday evening when the Soyuz TMA-19 docks at the station and its three-person crew joins the current Expedition 24 mission team commanded by Alexander Skvortsov of Russia, with cosmonaut Mikhail Kornienko and American astronaut Tracy Caldwell Dyson as flight engineers.

An unmanned Russian cargo ship is also slated to launch toward the space station later this month.

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