NASA crew prepares for mission to the International Space Station

NASA is preparing to send four astronauts to the International Space Station (ISS) on Friday, marking the arrival of a replacement crew after an earlier-than-planned evacuation triggered by a medical issue.

The US space agency is targeting February 13 for the launch of the Crew-12 mission aboard a SpaceX Falcon 9 rocket, with lift-off scheduled for 5:15 a.m. local time (10:15 GMT). The pre-dawn launch had been postponed by two days due to unfavorable weather conditions along the US East Coast, including strong winds that could have affected emergency procedures.

If the mission proceeds as planned, the spacecraft is expected to dock with the orbiting ISS at around 3:15 p.m. on Saturday. Crew-12 includes American astronauts Jessica Meir and Jack Hathaway, French astronaut Sophie Adenot, and Russian cosmonaut Andrey Fedyaev. The four have been in pre-flight quarantine at NASA’s Kennedy Space Center in Florida.

They will replace Crew-11, which returned to Earth in January about a month earlier than scheduled, marking the first medical evacuation in the space station’s history. Since then, the ISS has been maintained by a reduced crew of three. NASA has not released details about the health issue that led to the early return.

Orbiting about 250 miles (400 kilometers) above Earth, the ISS has been continuously inhabited for nearly 25 years. The ageing space laboratory is expected to be decommissioned around 2030, when it will be guided into Earth’s atmosphere to fall into a remote area of the Pacific Ocean.

Despite broader geopolitical tensions, the ISS has remained a rare platform for cooperation between Western nations and Russia, even after Moscow’s invasion of Ukraine in 2022. Still, those tensions have occasionally surfaced. In November, Russian cosmonaut Oleg Artemyev, who had been slated for Crew-12, was abruptly removed from the mission. Russian media reported he had been reassigned over security concerns, while the space agency Roscosmos said only that he had been moved to a different role. He was replaced by Fedyaev, who previously served aboard the ISS during Crew-6 in 2023.

Over their eight-month stay, the Crew-12 astronauts will carry out a range of scientific experiments, including studies on how microgravity affects the human body. Meir, a former marine biologist known for her research on life in extreme environments, will serve as mission commander.

Adenot will become the second French woman to travel to space, following Claudie Haigneré, who flew aboard the Mir space station. Adenot has said watching Haigneré’s launch as a teenager inspired her own path to spaceflight.

Among other projects, Adenot will test a new system that combines artificial intelligence and augmented reality to enable astronauts to perform medical ultrasound scans on themselves while in orbit.