The Russian Soyuz spacecraft is being prepared for launch on Friday, carrying a team of astronauts to the International Space Station (ISS). The crew includes NASA's Loral O'Hara, who will be making her first space flight, veteran commander Oleg Kononenko, and Nikolai Chub. The launch is scheduled for 11:44 a.m. EDT (8:44 p.m. local time) from the Baikonur Cosmodrome in Kazakhstan. The timing of the launch is intended to facilitate a fast-track rendezvous with the ISS, with a docking at 2:56 p.m. at the Earth-facing port of the Russian Rassvet module.

This mission will replace the current Soyuz crew consisting of commander Sergey Prokopyev, co-pilot Dmitri Petelin, and NASA astronaut Frank Rubio. The trio has been on a mission since September of last year and is set to return to Earth on September 27. This will conclude their extended 371-day mission, making it the longest single space flight by an American astronaut. Originally, their return was planned for March, but their Soyuz MS-22/68S spacecraft experienced a coolant leak in December, leading to a delay of an additional six months. They will now return to Earth aboard a replacement Soyuz launched in February.

Interestingly, both Kononenko and Chub plan to spend a full year aboard the ISS, mirroring the prolonged stay of the current crew. Meanwhile, O'Hara's tour of duty will last for six months. To facilitate crew rotations, the Russian space agency plans to launch a “taxi” flight in March of next year, with veteran commander Oleg Novitskiy, Tracy Dyson from NASA, and Belarus researcher Marina Vasilevskaya delivering a fresh ferry ship to the station. Following this, Novitskiy, Vasilevskaya, and O'Hara will return to Earth approximately ten days later, using the same Soyuz spacecraft that carries O'Hara to the ISS on Friday.

During their extended stay on the ISS, Rubio, Prokopyev, and Petelin have set a new U.S. single-flight endurance record. Rubio surpassed Mark Vande Hei's 355 days off planet on Monday, marking the first time an American astronaut has spent more than a year in space. The initial plan was for Prokopyev, Petelin, and Rubio to return to Earth in March. However, their Soyuz MS-22 ferry ship encountered a coolant leak due to a presumed micrometeoroid impact. After careful analysis, the Russians determined that cabin temperatures could exceed safety limits during re-entry, leading to the decision to launch an unpiloted replacement Soyuz in February. This successful mission allowed the crew to extend their stay for an additional six months.

Rubio's extended mission has posed challenges on a personal level, as he has missed significant milestones, including birthdays, anniversaries, and his son heading off to college. Nevertheless, he has received immense support from his family, who have handled the situation remarkably well. Rubio's endurance record was achieved on Monday, surpassing Vande Hei's previous record of 355 days and 3 hours. At the time of his landing on September 27, Rubio will have spent 370 days and 21 hours away from Earth.

The world record for the longest single spaceflight still belongs to cosmonaut Valery Polyakov, who spent 437 days and 18 hours aboard the Russian Mir space station in 1994-95. However, NASA astronauts are making significant strides in this area, with Scott Kelly, Vande Hei, Christina Koch, and now Rubio all surpassing the 300-day mark.

As Rubio, Prokopyev, and Petelin prepare to return to Earth, they will be replaced by the new Soyuz crew, consisting of Kononenko, Chub, and O'Hara. This continuous rotation ensures a constant presence on the ISS and facilitates scientific research and exploration in space.