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Space News · 2026-09-26

Boeing Starliner: How a $4.2 Billion Spacecraft Left Two Astronauts Stranded for Nine Months — and Whether It Flies Again

Two astronauts climbed into a Boeing spacecraft on June 5, 2024. They were supposed to be home in eight days.

They didn't come home for nine months.

That's the story of Boeing Starliner — a $4.2 billion capsule built to give America a backup to SpaceX Dragon. What happened to it is one of the most extraordinary chapters in commercial spaceflight history. And on September 28, 2026, NASA and Boeing are finally going to tell us what comes next.

$4.2BBoeing's NASA contract value

8 daysOriginal mission duration planned

9 monthsHow long the crew actually stayed

What was Boeing Starliner supposed to do?

Boeing Starliner — officially the CST-100 — was NASA's insurance policy. After the Space Shuttle retired in 2011, the US had to pay Russia $90 million per seat to put astronauts on the International Space Station. Every launch. Every time. That was a problem — not just financially, but strategically. So NASA funded two companies to build replacements: SpaceX got $2.6 billion to develop Dragon, and Boeing got $4.2 billion to build Starliner. More money. More headcount. More experience. The assumption was Boeing would deliver first.

SpaceX flew its first operational crew in November 2020. Starliner didn't carry its first crew until June 2024 — three and a half years later.

Key takeaway: Boeing received $1.6 billion more than SpaceX to build Starliner. SpaceX flew crew to the ISS three years before Boeing managed its first crewed test flight — and built a fully reusable rocket in that same window.

What went wrong on Starliner's first crewed flight?

The Crew Flight Test launched from Cape Canaveral on June 5, 2024, carrying veteran astronauts Butch Wilmore and Suni Williams. Docking with the ISS went smoothly. Then the engineers started looking at the data.

Five helium leaks. Small at first, then persistent. Then five of Starliner's twenty-eight reaction control thrusters failed during proximity operations — the tiny jets that give the capsule precise steering. Boeing engineers traced the issue to Teflon seals that had swollen in the heat, restricting propellant flow. Some engineers said the vehicle was still safe to fly home. Others weren't so sure.

NASA wasn't sure either. And in human spaceflight, not sure is the same as no.

5Helium leaks detected mid-mission

5 / 28Thrusters that failed during flight

6 weeksNASA spent analyzing the return risk

Why did NASA send Starliner home without its crew?

On August 24, 2024, NASA made the call. The agency concluded that the risk of thruster failure during reentry — the one phase of flight where you absolutely need control authority — was too high to accept with humans aboard. Butch and Suni would stay on the station. Starliner would fly home empty.

Boeing publicly disagreed. The company issued a statement maintaining the vehicle was airworthy: "We stand behind the safety of our vehicle and believe Starliner could have safely returned our crew." A major aerospace contractor arguing against NASA's risk assessment — about a spacecraft carrying NASA's own astronauts — was almost without precedent in the modern era.

To be fair: Boeing's engineers had data supporting their position. NASA's decision was based on probability models and risk margins — it was a judgment call, not a definitive failure. Both sides had qualified people looking at the same numbers and reaching different conclusions. That ambiguity is part of why this story isn't over.

On September 6, 2024, Starliner undocked from the ISS, executed a perfect automated reentry, and landed in the New Mexico desert. No crew aboard. Proof the capsule could fly. Just not the proof that mattered most.

Butch Wilmore and Suni Williams waited.

286 days

Time Butch Wilmore and Suni Williams spent on the ISS — nearly 36× longer than their planned 8-day mission

How did the stranded astronauts finally get home?

They came back on a SpaceX Dragon. On March 18, 2025, after 286 days aboard the station, Wilmore and Williams splashed down off the Florida coast. Both were healthy. During the wait, Suni Williams had quietly become the American woman with the most cumulative time in space.

The image was almost impossible to process. Two NASA astronauts, originally placed inside a Boeing spacecraft, returning to Earth inside a SpaceX one. The most experienced aerospace company in the world had outsourced the rescue to a startup founded 22 years earlier by an internet entrepreneur.

You can track every crewed vehicle docked at the ISS right now — Dragon included — on the SkyLens live tracker. The orbital mechanics of docking approaches are genuinely beautiful when you watch them in real time.

What does Boeing Starliner's full history look like?

2014 — Contract awarded

NASA gives Boeing $4.2B and SpaceX $2.6B to develop separate commercial crew vehicles. Competition was the whole point.

December 2019 — Orbital Flight Test 1 aborts early

A software timer error prevents Starliner from reaching the ISS. It returns safely but the mission is widely considered a failure. Boeing absorbs the cost of a do-over.

May 2022 — Orbital Flight Test 2 succeeds

An uncrewed Starliner finally docks with the ISS. Boeing has now spent hundreds of millions of its own money above the NASA contract to fix problems that should have been caught earlier.

June 5, 2024 — First crewed flight launches

CFT carries Butch Wilmore and Suni Williams to the ISS on an 8-day test mission. Problems emerge within days.

August 24, 2024 — NASA pulls the crew

After six weeks of thruster and helium leak analysis, NASA rules crewed return too risky. Starliner will fly home unmanned.

September 6, 2024 — Starliner lands alone

Perfect automated landing in New Mexico. The hardware works. The crew just isn't in it.

March 18, 2025 — Crew returns on Dragon

Wilmore and Williams splash down safely after 286 days — aboard a SpaceX capsule.

September 28, 2026 — NASA/Boeing press conference

NASA and Boeing leadership announce plans for Starliner's development and the path to regular crew flights. The first real answer to: what happens next?

Is Boeing Starliner cancelled?

No — and that's the part most people get wrong. Despite everything, Starliner is still a going programme. NASA has not cancelled the contract. The agency has repeatedly said that having only one commercial crew vehicle is itself a risk. If Dragon has a serious problem, there is no backup. The ISS could face the same abandonment scenario it nearly faced in 2018 when a Soyuz abort left the station temporarily without a safe crew vehicle.

Competition is not just good optics. It's how you keep people alive in space. NASA needs Starliner to work — which is exactly why it hasn't given up on it.

$1.5B+Boeing's estimated cost overrun above NASA funding

6Operational SpaceX Dragon crew missions before Starliner's first crewed flight

2030Current ISS operational end date — the window Starliner must fly in

What does Boeing need to fix before crew can fly on Starliner again?

The core engineering problem is the thruster seals — the Teflon material that swelled under heat and blocked propellant flow. Boeing is redesigning the seal geometry and testing alternative materials. NASA will also require more conservative ground acceptance testing: the leaks and thruster issues that appeared mid-flight were not caught on the pad, and that gap in the test programme is the deeper problem.

But hardware is only half of it. NASA's flight directors need to trust the vehicle again — and that trust is rebuilt through process transparency, testing that leaves nothing ambiguous, and ideally a successful uncrewed demonstration that performs exactly as predicted. Boeing's 737 MAX crisis showed what happens when engineering anomalies get minimised rather than escalated. NASA flight operations knows that history as well as anyone.

Key takeaway: The thruster problem is an engineering problem — it has a solution. The harder question is whether Boeing's internal safety culture has changed enough to catch the next anomaly before it becomes a crew safety issue. The September 28 announcement will give the first real signal of how both organisations are thinking about that.

Why does it matter whether Starliner ever flies crew again?

Because monopolies in access to space are dangerous in ways that aren't obvious until something goes wrong. If SpaceX Dragon is the only path for American astronauts to reach the ISS, then US human spaceflight has a single point of failure. One technical problem, one regulatory issue, one corporate decision — and the station goes dark. That's a real strategic vulnerability, not a hypothetical one.

A functioning Starliner means competition, which historically drives down costs, raises standards, and gives mission planners options. The $90 million per seat the US paid Russia in the years before commercial crew is a number worth keeping in mind: that's where the programme ends up when there are no alternatives.

Read more about how spacecraft reach and maintain their orbits on the SkyLens orbit explainer — and see how Dragon and Starliner's ISS approach trajectories compare.

$90M

Per seat the US paid Russia to reach the ISS before commercial crew existed — the cost of having no alternative

What should we expect from the September 28 announcement?

NASA's official description is carefully worded: leadership will discuss "Starliner's development and plans for regular crew flights." The phrase regular crew flights — plural — suggests Boeing has a concrete timeline on the table, not just aspirations. Whether that timeline includes a second uncrewed demonstration before crew flies again, or a direct path to CFT-2 based on ground-tested fixes, is the key variable. The decision will tell you exactly how much risk both organisations are willing to accept to save a programme that has already cost billions more than it was supposed to.

What we don't know yet: the specific fix certification approach, the launch date target, whether NASA will require a full stand-alone uncrewed mission, and how many operational missions Boeing is committing to before the ISS retirement window closes.

Here's what we know vs. what we don't: Confirmed — the thruster seal is the primary engineering target; Boeing is still under contract; the ISS needs a second crew vehicle. Unknown — the precise CFT-2 timeline, whether an uncrewed demo is required, and how NASA will certify the fix. The press conference on September 28 is the first time the public will hear both sides commit to specific language. That language matters.

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Whatever the announcement brings, the Starliner story is already a defining chapter in the new space age — not just because of the engineering failure, but because of what it revealed about the gap between legacy aerospace and a generation of companies that simply refused to fail the same way. The next chapter starts in two days.

SkyLens editorial — live CelesTrak + NASA/JPL data (16022 objects)