The National Aeronautics and Space Administration (NASA) admitted to having a ‘difference of opinions’ with Boeing during a discussion over the return plan for astronauts Sunita Williams and Bitch Wilmore.

Steve Stich, manager, Commercial Crew Program, NASA Kennedy Space Center, said at a press conference late Wednesday that it “was a tough decision to make” and that “it was really hard to determine whether to be uncrewed or not”.

“I would say the teams were very split…and [due to the] uncertainty relative to the thruster…the NASA team chose to return Butch and Suni on [SpaceX] Dragon,” Stich said.

When asked if there were “heating discussions” or “almost a shouting match” between the teams of NASA and Boeing during the meeting, Stitch said, “I wouldn’t say it was a yelling screaming kind of meeting…it was a tense technical discussion…,” Stitch said.

“The last meeting we had, where we talked about technical data on the different positions and analysis…I would not characterize it as heated…anytime you are in a meeting of this magnitude where there is this kind of decision, there is some tension in the room,” Stitch added.

Further explaining the issue, the NASA official said Boeing believed in the model they had created that tried to protect the thruster degradation for the rest of the flight.

But “the NASA team looked at the model and saw some limitations in it,” he added. “It really had to do with – do we really have confidence in the thrusters and how much we can protect our degradation from undock through deorbit burn. The NASA team, due to uncertainty in the modelling, could not get comfortable with that,” Stich said.

Meanwhile, Dana Weigel, manager, International Space Station, explained Boeing’s perspective, saying that Boeing “is in a bit of a different position in terms of our understanding about the risks and what’s available to us without Starliner”.

“So that’s also a reason for the difference of opinions…Boeing also said earlier that…they can’t weigh on that part of the agency (NASA),” Weigel said.

NASA decided to return Boeing’s Starliner spacecraft back to Earth without its crew members Sunita Williams and Butch Wilmore due to uncertainties with he spacecraft.

NASA said Wednesday that everything is on track for the Starliner capsule to undock from the space station Friday evening. The fully automated capsule will aim for a touchdown in New Mexico’s White Sands Missile Range six hours later.

Meanwhile, NASA’s two astronauts who flew up on Starliner will remain behind at the orbiting lab. They’ll ride home with SpaceX in February 2025, eight months after launching on what should have been a weeklong test flight.