‘Root Cause’ of Starliner Problems Possibly Found, But Astronauts’ Return Remains Uncertain

By: Sam Watanuki | Published: Jul 26, 2024

Boeing’s Starliner spacecraft has faced numerous challenges during its inaugural crewed test flight, leaving the return date for astronauts Butch Wilmore and Suni Williams uncertain.

Over the past few weeks, NASA and Boeing have been working tirelessly to understand and resolve these issues.

Initial Troubles

The Starliner experienced significant problems including helium leaks and malfunctioning thrusters on its journey to the International Space Station (ISS).

Boeing’s Starliner spacecraft approaching the International Space Station amid black space.

Source: Bob Hines/NASA/Wikimedia Commons

These issues raised concerns about the spacecraft’s ability to safely bring the astronauts back home.

Ground Testing in New Mexico

To get to the bottom of these problems, engineers conducted extensive tests at a site in New Mexico.

Boeing’s Starliner craft seen on its launchpad in the evening.

Source: NASA/Joel Kowsky/Wikimedia Commons

They fired the test engines more than 1,000 times, simulating the thrusters’ operation during both the outbound and return trips.

Discovering the Thruster Issue

The tests helped engineers understand that heat buildup inside the thrusters might be causing Teflon seals to bulge.

A Boeing Starliner test launch seen in progress with clouds of smoke around the launch pad in 2022.

Source: NASA/Joel Kowsky/Wikimedia Commons

This bulging restricts the flow of propellant, which could explain the unexpected shutdowns of the thrusters during flight.

Impact of Manual Maneuvers

NASA and Boeing decided that astronauts would not manually fly the Starliner during its return.

Boeing’s Starliner craft approaching the International Space Station with Earth seen below it.

Source: Bob Hines/NASA/Wikimedia Commons

Steve Stich, NASA’s Commercial Crew Program manager, mentioned that manual maneuvering during the trip to the ISS had put extra stress on the thrusters.

Helium Leaks Investigation

In addition to the thruster issue, engineers have been investigating helium leaks that occurred during the spacecraft’s journey.

Workers putting together the Starliner capsule in a factory in 2019.

Source: NASA/Wikimedia Commons

Analysis of components on the ground suggested that exposure to propellant vapor might have degraded the seals.

Potential Solution for Seals

To address the helium leaks, Boeing plans to replace the current seals with materials that are less susceptible to degradation by propellant vapor.

A group of many people who are mission managers with NASA, Boeing, and United Launch Alliance during a test flight for the Starliner capsule.

Source: NASA/Wikimedia Commons

This change aims to prevent similar issues in future Starliner missions.

Continuing Tests in Space

NASA and Boeing will conduct further tests on the Starliner’s thrusters while it remains docked at the ISS.

Astronauts Sunita Williams and Barry Butch Wilmore in front of the Boeing Starliner craft.

Source: NASA/Kim Shiflett/Wikimedia Commons

This includes firing 27 thrusters to better understand the helium leak issue and ensure the stability of the spacecraft’s systems.

Review and Analysis

The ongoing tests and analyses are crucial for determining whether the Starliner is ready to safely bring the astronauts back home.

An up-close look at the Starliner capsule and its rocket seen on its launchpad in the daytime.

Source: NASA/Joel Kowsky/Wikimedia Commons

A comprehensive review will be conducted to finalize preparations for the spacecraft’s undocking and return.

Confidence in the Starliner

Mark Nappi, Boeing’s Commercial Crew Program manager, expressed confidence in the vehicle’s readiness.

An up-close look at the top of Boeing’s Starliner craft seen in the daytime.

Source: NASA/Joel Kowsky/Wikimedia Commons

“Of course, I’m very confident we have a good vehicle to bring the crew back with,” he stated, reflecting the team’s cautious optimism.

Contingency Plans

Despite the progress, NASA has contingency options if the Starliner is not approved for the astronauts’ return.

NASA astronauts Suni Williams and Butch Wilmore posing and smiling in front of the Starliner capsule.

Source: NASA/Wikimedia Commons

Steve Stich emphasized the importance of understanding the helium leaks and managing them effectively before making a final decision.

Awaiting the Final Decision

As of now, Wilmore and Williams have been in space since June 6, and their mission duration is approaching the maximum limit of 90 days.

People collect parachutes and parts of the Starliner craft after it lands during sunrise.

Source: NASA/Bill Ingalls/Wikimedia Commons

NASA and Boeing aim to ensure a safe return, with the possibility of undocking taking place as early as late next week.