NASA has it again postponed the return to Earth of Barry Wilmore and Sunita Williams, the astronauts stuck on the International Space Station later Boeing's Starliner capsule malfunctioned in the middle of this year.

The spacecraft crew arrived at the ISS in June. The objective was to test the complete capability of the Starliner, including the launch, docking and return systems. The mission was scheduled to last a week. Five of the capsule's 28 thrusters failed to function before docking with the ISS. Boeing claimed that its technology could guarantee the safe return of astronauts. However, NASA expressed doubts and concluded that the risk was too high. The agency entrusted the task SpaceX.

Elon Musk's company launched the Crew-9 mission in September to, among other things, return Williams and Wilmore. Until now, the astronauts settled were expected back in February aboard the Crew Dragon gunship. However, NASA has announced that it expects the expedition to return to the Earth's surface after the arrival of Crew-10, which will be sent at the end of March 2025 at the earliest.

The adjustment will allow SpaceX and NASA engineers to finalize the development of a new Dragon spacecraft, which will be shipped to the company's facility in Florida early next month.

"The fabrication, assembly, testing and final integration of a new spacecraft is a painstaking endeavor that requires great attention to detail," said Steve Stich, manager of NASA's Commercial Crew Program, in a statement. "We appreciate the hard work of the SpaceX team to expand the Dragon fleet in support of our missions and the flexibility of the station program and the expedition crews as we work together to complete the preparation of the new capsule for the flight".

NASA said the Crew-9 and Crew-10 crews will complete a "handover period," during which the ISS residents share experiences and knowledge with the new arrivals. This process ensures the proper functioning of scientific experiments on board and the maintenance of the orbital complex.

NASA and SpaceX specialists evaluated several options for coordinating the next crew delivery. They determined that the March launch for Crew-10 was the "best option to meet NASA's requirements and achieve the space station's goals by 2025," according to an agency press release.

A long run

The ISS received two resupply flights in November, ensuring crew members have enough food, water, clothing and oxygen. However, some experts have warned of potential health risks for Wilmore and Williams after spending more than nine months in space.

The scientific community has been studying the effects of spaceflight on the human body since the 1970s. In the years since the first moon landing, it has he identified the conditions such as loss of bone mass, weakened heart function, visual problems, and the development of kidney stones.

A recent study from University College London reveals that the structure and function of the kidneys can also suffer permanent damage, although it is particularly aggressive in the cases of astronauts who go too far from Earth, which is not the case on the ISS.

NASA indicates that the crew of expeditions to the ISS usually make extended stays, with an average duration of six months. He adds that some astronauts have carried out missions of up to a year to contribute to research on human adaptation to space flight, with a view to future lunar and Martian exploration.

This story originally appeared WIRED in Spanish and was translated from the Spanish.