NASA astronauts Barry Wilmore and Sunita Williams embarked on a seemingly straightforward mission to the International Space Station (ISS) on June 5. Their objective was to test-fly the Boeing Starliner crew capsule, marking its first human-crewed mission, evaluate its systems, including manual controls, dock with the ISS, and return to Earth within a week. However, what was planned as an eight-day mission has turned into an eight-month saga, with NASA now predicting that the astronauts will return only in 2025. A helium leak and malfunctioning thrusters on Starliner have caused this significant delay. Although Boeing remains hopeful, it appears increasingly unlikely that Wilmore and Williams will return to Earth aboard the Starliner.
Currently, the ISS is home to nine astronauts as part of Expedition 71. The team includes Williams, Wilmore, Oleg Kononenko, Nikolai Chub, Tracy Caldwell-Dyson, Matthew Dominick, Michael Barratt, Jeanette Epps, and Alexander Grebenkin. Kononenko and Chub arrived earlier via the Soyuz MS-24 spacecraft during Expedition 70, while Caldwell-Dyson joined them on March 25 aboard Soyuz MS-25. The trio is scheduled to return on September 24 aboard Soyuz MS-25. Meanwhile, Dominick, Barratt, Epps, and Grebenkin arrived on the SpaceX Crew-8’s Dragon Endeavour on March 5 and are also slated for a September 2024 return.
As Expedition 71 prepares for its return journey, the crew will transition control of the ISS to Expedition 72, set to begin on September 24 with a seven-member team. Williams and Wilmore were initially supposed to leave before Expedition 72 began, but due to Starliner’s thruster issues, their stay at the ISS has been extended.
The ISS remains well-stocked with supplies. On August 14, the Progress MS-28 resupply ship delivered around three tonnes of food, fuel, medical supplies, and scientific equipment, ensuring that the crew’s needs are met for the foreseeable future. A week earlier, the Cygnus NG-21 American cargo spacecraft had also delivered 3.8 tonnes of cargo, including crew supplies, research equipment, spacewalk gear, and hardware for ISS maintenance.
With an extended mission, living conditions aboard the ISS are carefully managed. The station lacks laundry facilities, so astronauts wear clothing for extended periods before discarding them. Exercise gear is changed weekly, while other clothing is worn for weeks. Discarded items are stored in cargo ships, which are then released to burn up in Earth’s atmosphere.
Space on the ISS is at a premium, especially with more crew members than sleeping pods. Astronauts often sleep in sleeping bags fastened to any available surface. Exercise routines are tightly scheduled to ensure all crew members can maintain their physical health in the microgravity environment.
Unexpected delays are not uncommon in space missions. Past incidents have seen astronauts extend their stays due to various technical issues. Notably, in 1979, Soviet cosmonauts had to extend their mission by over two months due to a faulty spacecraft. More recently, U.S. astronaut Frank Rubio and two cosmonauts spent 371 days in space—double their original mission—due to damage to their return craft.
NASA has contingency plans in place if Starliner remains grounded. The Crew 9 Dragon mission, set to launch in September 2024, could return Wilmore and Williams to Earth in early 2025. If necessary, NASA may send a reduced crew for Expedition 72, making space for Wilmore and Williams on the return flight.
As this mission continues to unfold, the resilience and adaptability of the astronauts and mission teams highlight the complexities of human space exploration.