The Starliner spacecraft docked with the International Space Station and orbiting 262 miles above Egypt's Mediterranean coast on June 13. NASA says additional testing is needed before Starliner can return to Earth.

The Starliner spacecraft docked to the International Space Station and orbiting 262 miles above Egypt's Mediterranean coast, on June 13. NASA says additional testing is needed before Starliner can return to earth. / AP

When astronauts Butch Wilmore and Suni Williams lifted off from Cape Canaveral Space Force Station in Florida on June 5, they thought they’d be back in plenty of time for the Juneteenth holiday.

The two were test-driving Boeing’s newest spaceship, called Starliner. All they had to do was put it through its paces, dock briefly with the International Space Station (ISS), and come home. The entire mission was supposed to last around a week.

Instead, a series of leaks and malfunctions have caused NASA to indefinitely delay the duo’s return.

Just whatever you do, don’t say they’re stranded.

“We’re not stuck on ISS,” Mark Nappi, Boeing’s vice president for its Commercial Crew Program, told reporters in a news conference on June 28. “The crew is not in any danger and there’s no increased risk when we decide to bring Suni and Butch back to Earth.”

Here’s what’s going on with Boeing’s newest spacecraft.

NASA’s Boeing Crew Flight Test astronauts Butch Wilmore and Suni Williams are seen aboard the International Space Station. The astronauts have had their return to Earth delayed while NASA conducts additional testing on Starliner's thrusters.

NASA’s Boeing Crew Flight Test astronauts Butch Wilmore and Suni Williams are seen aboard the International Space Station. The astronauts have had their return to Earth delayed while NASA conducts additional testing on Starliner's thrusters. / NASA

Even before this launch, there were problems

The development of Starliner has not gone smoothly. During its first test flight in 2019, which didn’t have people on board, it failed to reach its expected orbit. The problem was later traced to an onboard clock that was set incorrectly — causing the Starliner’s thrusters to fire at the wrong time.

Starliner never made it to the ISS on that trip, and NASA required a second test flight without any astronauts. When it launched again in 2022, two thrusters on Starliner failed to fire as expected. It successfully switched to backup thrusters and docked to the space station.

Astronauts were finally supposed to launch last year, but then Boeing found two more problems with the spacecraft: issues with the parachute system that would allow them to float back to Earth, and tape used to hold wiring that posed a potential fire risk. Fixing both issues pushed back the launch to this spring.

Finally, Williams and Wilmore were strapped in on May 6, when more problems appeared — a stuck valve on the rocket launching Starliner had to be replaced, and mission engineers discovered the Starliner itself was leaking helium.

Helium gas is used to pressurize Starliner’s propulsion system, and NASA took several weeks to determine the leaks weren’t serious enough to cause the helium to run out during the mission.

Boeing's Starliner capsule atop an Atlas V rocket finally lifted off from Space Launch Complex 41 at the Cape Canaveral Space Force Station on June 5. The launch came after years of delays and setbacks.

Boeing's Starliner capsule atop an Atlas V rocket finally lifted off from Space Launch Complex 41 at the Cape Canaveral Space Force Station on June 5. The launch came after years of delays and setbacks. / AP

Thruster cluster leads to fluster

When all systems were finally “go,” Starliner’s launch went off without a hitch. On June 5, Williams and Wilmore sailed into orbit.

But as they approached the ISS, new problems appeared. Five of 28 “Reaction Control System” thrusters aboard Starliner’s service module shut themselves down unexpectedly, and the spacecraft was left holding just outside the docking port, while engineers did some troubleshooting.

Eventually, the spacecraft docked successfully with the space station, and four of the five thrusters were brought back online. But NASA later disclosed it had found four additional helium leaks in different parts of the spacecraft, bringing the total to five.

NASA now says that it needs to conduct additional testing and evaluation of these issues before Williams and Wilmore can return to Earth. Space agency engineers suspect that faulty seals may be behind the helium leaks, which they think pose little risk. But the thruster issues have been harder to pin down.

NASA says that starting this week, it will be conducting extensive tests of a Starliner thruster at its White Sands Test Facility in Las Cruces, N.M. The test thruster will be put through simulated launches, dockings and landing burns, to see if engineers can replicate the problems, and also confirm that the thrusters can safely be used to bring Williams and Wilmore home.

“Once that testing is done, then we’ll look at the plan for landing,” Steve Stich, the program manager on NASA’s Commercial Crew Program, told reporters. The entire process could take several weeks, he says.

Don’t say stuck

Even before the latest press conference, news media was speculating that Williams and Wilmore might be stuck aboard the station. It’s a claim that Boeing, in particular, seems to bristle at.

“The astronauts are not stranded at the ISS,” read the first line of the company’s statement on the matter, which NPR received on June 26.

As Starliner prepared to dock with the International Space Station, several thrusters failed to fire as expected.

As Starliner prepared to dock with the International Space Station, several thrusters failed to fire as expected. / AP

“They’re not stuck in space,” agrees Laura Forczyk, executive director of Astralytical, a space consulting group. The astronauts are comfortably housed at the International Space Station.

Starliner is designed to remain in space up to 210 days, according to Stich. This test flight was originally supposed to be limited to 45 days, due to the spacecraft’s battery life, but Stich says the space station is recharging the batteries as designed, and NASA is looking to extend that limit.

In a real pinch, NASA could use either a SpaceX Dragon capsule or a Russian Soyuz capsule to bring the duo home, but Forczyk doubts that will be necessary.

“I don’t see this as being anything critical, or life-threatening,” Forczyk says. “I just think they’re being extra cautious as they should be, because this vehicle is not operating as intended.”

Forczyk notes that the problems with the helium system and the thrusters are located in Starliner’s service module, a section of the spacecraft that will be jettisoned before landing. For that reason, she says, engineers may want to keep Starliner at the station longer, so they can gather more data from the module before it burns up during reentry.

As further evidence of NASA’s confidence in Starliner, Williams and Wilmore took shelter inside the spacecraft last week, after a Russian satellite broke apart, creating orbital debris that could have threatened the station.

“Butch and Suni got in the spacecraft, powered up the vehicle, closed the hatch, and were ready to execute … an emergency undock and landing,” Stich says.

Starliner’s future could be in limbo

In 2014, Boeing received a $4.2 billion contract from NASA to build Starliner. The spacecraft was supposed to ferry astronauts regularly to and from the International Space Station within the decade. Those flights are now years behind schedule, and the delays have cost Boeing at least $1.5 billion in losses.

Meanwhile, rival company SpaceX, which was awarded just $2.6 billion, successfully flew humans in 2020 and has completed eight regular crewed missions for NASA to the space station.

Ron Epstein, an analyst at Bank of America, says that the problems are part of bigger issues at the aerospace giant. “I don’t think you can look at it in isolation,” he says.

Boeing has also seenproblems with its 737 Max aircraft, including a door that flew off an aircraft earlier this year, and its delivery of two 747s to be used as the presidential Air Force One has also been delayed.

Starliner will eventually land somewhere in the western U.S., just as it did during an uncrewed flight test in 2022.

Starliner will eventually land somewhere in the western U.S., just as it did during an uncrewed flight test in 2022. / NASA/AP

At its root, Epstein says these issues are caused by a move away from “hardcore engineering” within the company’s management.

“You have management teams over a number of years that have focused more on shareholder return than the core engineering business of the company,” he says.

Starliner’s first regular flight carrying astronauts to ISS is now scheduled for February 2025, but it’s unclear whether NASA will certify the new spacecraft in time. Even if it did, it would likely conduct just a handful of flights before NASA retires the Space Station in 2030.

Given all that, Epstein says it’s possible that, if NASA requires extensive modifications and fixes to Starliner, Boeing may decide to walk away from the program altogether.

“Boeing management has been clear, I think, to the investment community that Starliner and certain aspects of space are just not core to them,” he says. “I wouldn’t be surprised if the company wouldn’t want to continue.”

But Boeing’s Nappi says the company is fully committed to Starliner. “The plain and simple answer to the question is: ‘No, we’re not going to back out,’ " he says. “This is our job.”