Three astronauts from the United States, Japan and Russia received the go-ahead Saturday for a holiday season rocket launch to the International Space Station from Russia's remote space complex in southern Kazakhstan.
Their Soyuz TMA-17 spacecraft has been hoisted into place at the Baikonur center for a mission that will boost the number of crew at the orbital laboratory to five members.
NASA's Timothy J. Creamer, Russian cosmonaut Oleg Kotov and Soichi Noguchi of Japan will blast off Monday at 3:52 a.m. local time (4:52 p.m. EST Sunday, 2152 GMT) in the first-ever launch of a Soyuz spaceship on a winter night.
Creamer, who is making his maiden voyage to space, says he plans to keep people back on Earth up-to-date via Twitter.
"I thought if I can give you the status of what I am doing, what we are hoping for, what we are looking forward to seeing, those would be good little teasers," he said at a news conference after a medical check on the three astronauts.
Since arriving for training in Baikonur earlier this month, Creamer has been using tweets to keep in touch with space enthusiasts and well-wishers.
One recent tweet read: "Da da da!! Ready and raring to go!"
After liftoff, the Soyuz will travel for about two days before docking with the space station 350 kilometers (220 miles) above Earth.
Creamer said it was sad to be leaving family and friends behind over the Christmas holidays, but that space travel brought some consolation.
"I also have to say we are going as a family together to a family in space," he said.
The space station swung into the festive mood this week with a video Christmas greeting beamed to Earth daily by its current occupants.
On its Web site, NASA has created a series of virtual postcards for members of the public to send to the space station with their holiday greetings.
Kotov is traveling to the space station for his second time, having served as a flight engineer in 2007, and will take over as commander of Expedition 23 in March.
The three astronauts will be joining Jeff Williams, a NASA astronaut, and Russia's Maxim Surayev, who have been alone on the space station since the start of the month.
The first space station crew arrived in 2000, two years after the first part was launched. Until the May launch, no more than three people lived up there at a time. The space outpost has since expanded to accommodate a permanent crew of six.
With the U.S. shuttle fleet set to be grounded soon, NASA and other international partners will have to rely on Russian Soyuz spacecraft alone to ferry their astronauts to the space station and back.