(AP) -- A NASA astronaut and two Russian colleagues received the thumbs-up Thursday for a mission that will boost the population of the International Space Station to six.
California native Tracy Caldwell Dyson and Russians Alexander Skvortsov and Mikhail Kornienko are to blast off at 10:04 a.m. (0404 GMT) Friday from the Russian-leased Baikonur space center in southern Kazakhstan and will reach the orbiting science lab on Easter Sunday.
The astronauts are due to stay on board the space station until mid-September, leaving the lab just as the Shuttle Discovery sets off from the Kennedy Space Center in Florida in the last-ever shuttle flight.
Speaking at a press conference Thursday, Caldwell Dyson spoke of her sadness at seeing the end of the venerable U.S. spacecraft, which has been ferrying astronauts into space since the early 1980s.
"It's bitter, because we're saying goodbye to such a tremendous part of our space program," she said. "We've spent more time in that shuttle than we have in any vehicle and it has blessed with a space station today and many experienced astronauts."
Caldwell Dyson, Skvortsov and Kornienko spoke to reporters Thursday from behind the glass wall protecting them from contamination. Ahead of the launch day, astronauts have restricted exposure to the outside world to ensure that they do not fall victim to infection.
The three astronauts departing Friday will join Russian commander Oleg Kotov, NASA astronaut Timothy J. Creamer and Soichi Noguchi of Japan on board the station.
With the winding-down of the shuttle, the Soyuz - which launched the world's first satellite into space in 1957 - is set to take on the burden of carrying astronauts to and from the space station.
Explore further: How bad can solar storms get?