After more than nine months in space, the crew of the Boeing Crew Flight Test mission are ready to return home. Barry “Butch” Wilmore and Sunita “Suni” Williams boarded SpaceX Crew Dragon C212 Freedom and undocked from the International Space Station on March 17, and are set to splash down off the coast of Florida on March 18.
They are joined by NASA astronaut Nick Hague and Roscosmos cosmonaut Aleksandr Gorbunov, who launched on Freedom, which contained two empty seats that are now being used by Wilmore and Williams, back in September 2024 for NASA’s Crew-9 mission.
This mission will mark SpaceX’s final east coast splashdown, with all future Dragon recovery operations moving out to the Pacific Ocean. This follows incidents with other reentries that saw Crew Dragon’s trunk, an unpressurized segment of the spacecraft that must be jettisoned before encountering reentry heating, landing outside of predicted areas. Debris from previous Dragon trunks have been found in places like Australia.
Freedom undocked from the space-facing docking port on the Station’s Harmony module at 05:05 UTC on Tuesday, March 18. Dragon and its four crew members are expected to splash down just before 6:00 PM EDT (22:00 UTC). With an on-time splashdown, Wilmore and Williams will have spent 286 consecutive days in space for the mission.
The Crew-9 astronauts onboard their return capsule prior to undocking. (Credit: NASA)
The two Boeing Crew Flight Test (CFT) astronauts have been on a long journey since their initial launch aboard a United Launch Alliance (ULA) Atlas V from Cape Canaveral on June 5, 2024.
The launch suffered several delays, including a small helium leak in the service module noted on the first launch attempt in May. Located inside of one of the reaction control system thrusters onboard the vehicle that help with in-orbit maneuvers and deorbiting, the issue revealed an additional “design vulnerability” that led to the creation of an additional deorbit procedure in the event of further problems. One such problem could have seen eight orbital maneuvering thrusters unable to perform a deorbit burn, leaving Starliner in orbit.
After a second launch scrub due to a ground computer issue, Starliner finally launched on what was expected to be an eight-to-10-day mission. During the first hours of the flight, helium leaks were noticed in the propulsion system. Eventually, five leaks were discovered, but the leak rate was slow enough that the mission could proceed to rendezvous and docking operations.
NSF’s Sawyer Rosenstein asked officials about the mission duration in June 2024 and if any in-flight events would lead to a mission extension shortly after the launch.
“You [have got to] check out the system and see what the system gives you,” deputy associate administrator for NASA’s Space Operations Mission Directorate Joel Montalbano responded. “If you see something unexpected and we’re like, ‘hey another day would allow some extra time to go look at that extra system,’ then we’d stay…it’s more watch how the system operates and if we need more time, we have more time.”
As Starliner, named Calypso, began its rendezvous procedure, five thrusters failed. Teams noticed a severe degradation in thrust from the thrusters, and controllers needed to try to get them back online as soon as possible. Four were eventually returned to service.
The Boeing CFT mission launches aboard a ULA Atlas V N22. (Credit: Sawyer Rosenstein for NSF)
This began a series of multiple mission extensions as crews discussed possible solutions to the thruster issues. Eventually, teams were faced with deciding whether to return Starliner with its two crew members or leave them aboard the Station and send Calypso home empty.
Starliner was initially rated for a 45-day stay at the Station when docked to the Harmony node module’s forward port. Mid-August was defined as the cutoff point for a decision if necessary, and, as July turned into August, there was still no consensus on whether Calypso should be brought home with its crew.
Tests conducted on the ground were able to recreate the thruster degradation seen during ascent and docking, and engineers believe the issue was likely caused by bulging seals in an oxidizer valve, restricting propellant flow to the thrusters.
Starliner Calypso undocks from the ISS uncrewed, as seen through the window of a SpaceX Crew Dragon. (Credit: NASA)
The biggest concern, however, was how the thrusters would perform during reentry, where attitude control and precision are critical as the spacecraft’s exterior faces temperatures of nearly 2,000 degrees Celsius.
With Wilmore and William’s mission continuing to face extensions, Calypso was reaching its cutoff point. Despite arguments from Boeing officials, NASA officials came to a unanimous decision and announced on Aug. 24 that they would return Starliner uncrewed.
Bringing Calypso home uncrewed meant that the upcoming Crew-9 mission would need to launch with two empty seats, which the two CFT astronauts would fill during Crew-9’s return.
Since Calypso occupied the docking port the Crew-9 Dragon would need, Starliner would have to depart the Station before Crew-9 arrived. This led to questions regarding an emergency egress option for Butch and Suni in the event of an emergency on the Station. It was determined that two makeshift seats could be made in a cargo area inside the pressurized Crew-8 Dragon Endeavour.
The uncrewed Starliner Calypso under three main chutes before landing at White Sands, New Mexico, to conclude the CFT mission. (Credit: NASA TV)
Starliner undocked and landed safely within a designated zone at White Sands, New Mexico, on Sept. 6, 2024. This allowed for the launch of Crew-9 on Dragon Freedom just a few weeks later, on Sept. 28.
Before the seating changes due to the issues with Boeing CFT, NASA astronauts Zena Cardman and Stephanie Wilson were scheduled to fly on Crew-9 with commander Nick Hague and cosmonaut Aleksandr Gorbunov. Cardman and Wilson were removed from Crew-9 to make room for the CFT astronauts, and Hague and Gorbunov launched with two empty seats inside Freedom. The pair docked to the ISS on Sept. 29.
Between the Crew-8 emergency egress contingency plan and the arrival of Crew-9, Wilmore and Williams were never without a ride home. Had something gone wrong, the two astronauts would have always had a safe option to return to Earth. With that in mind, NASA incorporated them into the Expedition 71/72 crew and extended their time on the Station.
Williams would go on to command the ISS and complete a spacewalk, making her the all-time leader amongst female astronauts in extravehicular activity (EVA) experience, with a total of 62 hours and six minutes spent outside the Station.
The CFT crew’s Boeing spacesuits were incompatible with SpaceX’s Dragon systems. Thus, Wilmore and Williams would need SpaceX spacesuits for their return, with Williams using a suit already onboard the Station and Wilmore receiving a custom suit via a cargo resupply mission. Should the Crew-8 emergency egress event have occurred, the crew would have used spare suits aboard the ISS.
Suni Williams conducts a spacewalk outside the ISS on Jan. 16, 2025. (Credit: NASA)
As is tradition, SpaceX and NASA plan for a handover period in which an incoming and outgoing crew are docked at the same time. That meant Crew-9 would return once the next flight, Crew-10 and its Crew Dragon, Endurance, lifted off and arrived at the ISS.
After a month delay following issues with a new Crew Dragon capsule that was ultimately swapped for Endurance, Crew-10 lifted off from Launch Complex 39A (LC-39A) at the Kennedy Space Center in Florida on March 14, docking to the station 28 hours later.
Associate administrator for NASA’s Space Operations Mission Directorate Ken Bowersox noted in a press conference following the launch of Crew-10 that this was the largest percentage extension of any mission based on the originally planned duration.
Bowersox has personal experience with the situation in which Wilmore and Williams are in. Launching aboard Space Shuttle Endeavour in November 2002, he was set to return aboard a future Space Shuttle mission. His mission was forced to be extended following the STS-107 Columbia disaster, which grounded the Space Shuttle fleet. He would later return home on the Soyuz TMA-1 spacecraft, which returned in May 2003.
Using his experience, he says the astronauts are not worried about that percentage extension.
“Every astronaut that launches into space, we teach them ‘don’t think about when you’re going home, think about how well your mission is going and if you’re lucky, you might get to stay longer,’” Bowersox said. “On my last flight, I did get to stay a little bit longer than was planned, and I was so happy I did get to stay longer… The only time [Don Pettit] and I ever came close to an argument was when we argued about who might get to stay longer.”
(Lead image: Crew Dragon Freedom undocks from the ISS with the four crew members of Crew-9. Credit: NASA)
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