CAPE CANAVERAL - A NASA astronaut and two Russian cosmonauts were preparing to head for the International Space Station in a Russian Soyuz rocket on Friday as replacements for a crew that ended a year-long flight earlier this month.
US astronaut Jeff Williams and cosmonauts Oleg Skripochka and Alexey Ovchinin are scheduled to blast off from the Baikonur Cosmodrome in Kazakhstan at 5:26 p.m. EDT (2126 GMT). They are due to arrive at the station about six hours later.
The men will spend about six months living and working aboard the $100 billion research laboratory that flies about 250 miles (400 km) above Earth.
NASA and Russia have not yet assigned crews for additional year-long missions following the March 1 return of astronaut Scott Kelly and cosmonaut Mikhail Kornienko from a 340-day spaceflight.
Williams, 58, who will be serving aboard the station for a third time, is expected to return to Earth with a career total of 534 days in space. This would surpass the current US record, which is Kelly's cumulative 520 days.
The world record belongs to Russian cosmonaut Gennady Padalka, who returned from his fifth flight last September and has spent a total of 879 days in space.