A Russian Soyuz rocket has been moved into place at the Baikonur Cosmodrome launch pad in Kazakhstan in preparation for the Saturday night blast-off of the spacecraft, which will carry a three-member crew to the International Space Station.
NASA flight engineer Sunita Williams, Aki Hoshide of the Japan Aerospace Exploration Agency and Russian Commander Yuri Malenchenko are set to blast off aboard the Soyuz TMA-05M at 10:40 p.m. ET.
The crew will spend two days travelling to the orbiting ISS laboratory and four months at the station itself. They will be joining three other astronauts who arrived at the station in May and three others who have been there since December.
The Reuters news agency reported on Thursday that schoolchildren in the Indian province of Gujarat, where Williams's father is from, participated in a prayer event to wish Williams a successful mission on Friday.
Williams herself was born in Ohio and raised in Massachusetts.
The July mission will be her second. She spent 195 days at the ISS in 2006-2007, breaking the record for the longest time spent in space by a female astronaut.
Canadian astronaut Chris Hadfield is the back-up astronaut for Williams and will replace her in the event of an emergency.
NASA's coverage of the launch begins at 9:30 p.m. ET. Saturday.