Days after NASA announced that two astronauts had been stranded on the International Space Station, the space agency had a series of contentious meetings with Boeing to determine how to bring them back to Earth, sources at both Boeing and NASA told The Post.

The meetings — attended by senior-level employees on both sides — were tense, and often devolved into yelling and arguments, sources said.

“It was heated,” said a NASA executive who is familiar with the talks.

“Boeing was convinced that the Starliner was in good enough condition to bring the astronauts home, and NASA disagreed. Strongly disagreed.

“The thinking around here was that Boeing was being wildly irresponsible.”

In the end, NASA decided to overrule Boeing’s wishes and have the company’s biggest rival — Elon Musk’s Space X — bring home Butch Wilmore and Suni Williams.

The two astronauts went up to the ISS in June for what was supposed to be an eight-day voyage and found themselves stranded when they discovered that helium leaks on Boeing’s Starliner — which they had known about prior to launch — were more numerous than previously thought.

Worse, the leaks were causing the thrusters to malfunction.

The Space X mission won’t happen until February, leaving the astronauts trapped aboard the ISS for nearly eight months.

“Boeing wasn’t happy,” says the NASA exec.

“And they made that perfectly clear to us. But what’s the headline if there’s a catastrophic failure? It’s not ‘Boeing killed two astronauts,’ it’s ‘NASA killed two astronauts.’ So no, it’s better safe than sorry.”

Execs at the aerospace giant also made their displeasure clear to top-level employees in an internal email last week that the company shared with The Post.

“I know this is not the decision we had hoped for, but we stand ready to carry out the actions necessary to support NASA’s decision,” Mark Nappi, the head of Boeing’s Commercial Crew Program, wrote to employees.

“The focus remains first and foremost on ensuring the safety of the crew and spacecraft. I have the utmost confidence in this team to prepare Starliner for a safe and successful uncrewed return with the same level of professionalism and determination as you did the first half of the mission.”

According to Boeing employees, the hope is that the Starliner will return safely to Earth, giving the company the leeway to claim that NASA was being overcautious.

But inside Boeing’s commercial space department, the demoralized team is reeling from the public setback.

For the past decade they have been in direct competition with Space X — and the latest developments have been humiliating to the company, one employee said.

They could also prove to be costly.

According to public records obtained, NASA awarded competing contracts to Boeing and Space X in 2014.

Boeing received $4.2 billion to build a transportation capsule to take six crews to the ISS.

Starliner malfunctioned on its maiden crewed voyage.

Meanwhile, SpaceX received $2.6 billion — but has managed to complete nine flights in its Crew Dragon capsule.

The tenth mission will be to rescue Wilmore and Williams.

The embarassment comes after a year of extraordinarily bad press for Boeing, since a door panel blew off an Alaska Airlines Boeing 737 MAX 9 jet.

At least 20 whistleblowers have come forward to voice concerns about safety and quality issues at the aerospace giant — and some of them have wound up dead.

But NASA is publicly standing behind Boeing, despite that the company’s own employees call a “massive screw-up.”

“I think the key word is partner,” NASA spokesman Bowersox said during the weekend press conference.

“A lot of people want to focus on the contractual relationship where we’re buying something from a company. This isn’t completely like that, right? We have a contract with Boeing, but it’s to work together to develop this capability for our country.”