A new crew of four astronauts is set to launch to the International Space Station (ISS) on Friday, September 15, 2023, to replace three astronauts who have been stuck in space for a year due to a damaged spacecraft. The launch will be the seventh crewed mission for SpaceX, the private rocket company founded by Elon Musk, and the sixth for NASA’s Commercial Crew Program.
A year-long ordeal for the stranded crew
The three astronauts who have been living and working on the ISS for a year are NASA’s Frank Rubio and cosmonauts Sergey Prokopyev and Dmitry Petelin. They flew to the orbiting laboratory in September 2022 aboard a Russian Soyuz MS-22 capsule, which was supposed to bring them back to Earth in March 2023. However, in December 2022, the capsule began leaking coolant from a tiny hole that was likely caused by a micrometeoroid impact. The coolant helps to regulate the temperature inside the crew compartment, which can reach up to 40 degrees Celsius without it. The leak also reduced the capsule’s ability to maneuver and dock with the ISS.
The stranded crew had to rely on another Soyuz capsule, MS-23, as a lifeboat in case of an emergency. NASA also considered using a SpaceX Dragon capsule as a backup option. However, the Russian space agency Roscosmos decided to launch an empty Soyuz capsule, MS-24, in February 2023 to replace the damaged one. The MS-24 capsule then docked with the ISS and waited for the arrival of a new crew.
A new crew to take over the ISS
The new crew that will launch on Friday is composed of NASA astronauts Mark Vande Hei and Megan McArthur, ESA astronaut Thomas Pesquet, and JAXA astronaut Akihiko Hoshide. They will fly on the SpaceX Crew Dragon Endeavour, which was previously used for the historic Demo-2 mission in May 2020. The Endeavour capsule will sit atop a Falcon 9 rocket, also built by SpaceX, and lift off from the Kennedy Space Center in Florida at 10:45 a.m. EDT (14:45 UTC).
The launch will be broadcast live on NASA TV and SpaceX’s website. The crew is expected to reach the ISS in about 24 hours and join the seven other crew members who are already on board. The crew exchange will mark the first time that 11 people will be on the ISS at the same time. The station can accommodate up to six spacecraft at a time, including two Soyuz capsules, two Dragon capsules, one Cygnus cargo ship, and one Progress cargo ship.
The new crew will stay on the ISS for about six months and conduct various scientific experiments, spacewalks, and maintenance tasks. They will also witness the arrival of the first module of the new Russian orbital segment, called Nauka, which is scheduled to launch in October 2023. The module will provide additional living and working space, as well as a new docking port and a robotic arm for the Russian side of the station.
A long-awaited return for the stranded crew
The three astronauts who have been stuck on the ISS for a year will finally return to Earth on Saturday, September 16, 2023, aboard the Soyuz MS-24 capsule. They will undock from the station at 7:35 a.m. EDT (11:35 UTC) and land in Kazakhstan at 11:00 a.m. EDT (15:00 UTC). Their landing will be also broadcast live on NASA TV and Roscosmos’ website.
The trio will have spent 365 days in space, which is the longest single spaceflight for a NASA astronaut and the second-longest for a cosmonaut. The record for the longest continuous spaceflight is held by cosmonaut Valeri Polyakov, who spent 437 days on the Mir space station from 1994 to 1995. The longest cumulative time in space is held by cosmonaut Gennady Padalka, who spent 879 days over five missions from 1998 to 2015.
The long-duration spaceflight will have exposed the stranded crew to various physical and psychological challenges, such as muscle loss, bone loss, radiation exposure, isolation, and stress. They will undergo extensive medical examinations and rehabilitation after their return to Earth. They will also provide valuable data and insights for future missions to the Moon and Mars, which will require longer stays in space.