Boeing's Starliner (CST-100) - Discussion Thread 6

[FutureSpaceTourist]

NEAF Briefs- NEAF Talks now in 12 minutes or less.

Filmed April 2025

What’s the real story behind the Boeing Starliner problems. Boeing Technical Fellow Tom Mulder gives the inside details with this exclusive story of exactly what took place and what’s next for Starliner.

Development of the Boeing Starliner spacecraft began in 2009 as a Space Shuttle replacement for crew and cargo delivery to the International Space Station (ISS). Vehicle design matured rapidly with the award of a NASA contract in September 2014, however numerous delays ensued and test flights did not begin until 2019  leading to additional problems and delays.  The first crewed flight test, CFT-1 with Butch Wilmore and Sunita Williams, finally took place in 2024 with less than optimal results.  As a member of the Starliner team since its inception, Tom Mulder will describe exactly what happened with CFT 1, and what does the future hold for Starliner.   

ABOUT THE SPEAKER-
TOM MULDER is the navigation, control, and mission designer for the Boeing CST Starliner. He is a Technical Fellow living in Temecula, California and working for the Boeing Office in Houston.  He is an Associate Fellow of the American Institute of Aeronautics and Astronautics (AIAA).  During his 43-year career, Tom worked in guidance, navigation, and control; specializing in rendezvous mission design for the Space Shuttle, International Space Station (ISS), Commercial Crew, and other Boeing space programs.  Tom designed the architecture behind CST-100 Starliner autonomous flight and requirements for guiding the vehicle during ISS rendezvous, departure, and deorbit.  Previously, Tom was Chief Engineer for a Boeing team that developed autonomous rendezvous technologies for advanced projects, including DARPA’s Orbital Express Program; for which Tom served as Rendezvous Director during its 2007 Earth-orbiting mission.  Tom graduated with an Aerospace Engineering Degree from Iowa State University.  Among his commendations are the Astronaut Office Silver Snoopy Award and Rotary Club Stellar Individual Award.

[StraumliBlight]

NEAF Briefs- NEAF Talks now in 12 minutes or less.

Filmed April 2025

What’s the real story behind the Boeing Starliner problems. Boeing Technical Fellow Tom Mulder gives the inside details with this exclusive story of exactly what took place and what’s next for Starliner.

At 10:45, he mentions "It hasn't been determined by NASA exactly what flights will take place in the future. I can only speculate that maybe we'll have a couple of flights next year, and then one flight per year after that. The last flight would be in 2030."

[catdlr]

https://youtube.com/watch?v=yQSxHi4AI-0

NEAF Briefs- NEAF Talks now in 12 minutes or less.

Filmed April 2025

What’s the real story behind the Boeing Starliner problems. Boeing Technical Fellow Tom Mulder gives the inside details with this exclusive story of exactly what took place and what’s next for Starliner.

Development of the Boeing Starliner spacecraft began in 2009 as a Space Shuttle replacement for crew and cargo delivery to the International Space Station (ISS). Vehicle design matured rapidly with the award of a NASA contract in September 2014, however numerous delays ensued and test flights did not begin until 2019  leading to additional problems and delays.  The first crewed flight test, CFT-1 with Butch Wilmore and Sunita Williams, finally took place in 2024 with less than optimal results.  As a member of the Starliner team since its inception, Tom Mulder will describe exactly what happened with CFT 1, and what does the future hold for Starliner.   

ABOUT THE SPEAKER-
TOM MULDER is the navigation, control, and mission designer for the Boeing CST Starliner. He is a Technical Fellow living in Temecula, California and working for the Boeing Office in Houston.  He is an Associate Fellow of the American Institute of Aeronautics and Astronautics (AIAA).  During his 43-year career, Tom worked in guidance, navigation, and control; specializing in rendezvous mission design for the Space Shuttle, International Space Station (ISS), Commercial Crew, and other Boeing space programs.  Tom designed the architecture behind CST-100 Starliner autonomous flight and requirements for guiding the vehicle during ISS rendezvous, departure, and deorbit.  Previously, Tom was Chief Engineer for a Boeing team that developed autonomous rendezvous technologies for advanced projects, including DARPA’s Orbital Express Program; for which Tom served as Rendezvous Director during its 2007 Earth-orbiting mission.  Tom graduated with an Aerospace Engineering Degree from Iowa State University.  Among his commendations are the Astronaut Office Silver Snoopy Award and Rotary Club Stellar Individual Award.

For those wishing to listen to the entire presentation:

[mn]

My initial reaction to this is that typically people on the inside will not talk until after the curtain closes...

I didn't watch this yet and I hope my initial reaction is wrong.

[kendalla59]

NEAF Briefs- NEAF Talks now in 12 minutes or less.

Filmed April 2025

What’s the real story behind the Boeing Starliner problems. Boeing Technical Fellow Tom Mulder gives the inside details with this exclusive story of exactly what took place and what’s next for Starliner.

I just watched the entire presentation. My first impression is that the presenter admitted to no errors or issues from his team, after the software mistake was fixed. The blame instead was (very gently) placed on Butch Wilmore, or more precisely NASA flight test planning, for exercising the thrusters manually. Also, Aerojet Rocketdyne was indirectly blamed, insofar as they were presumed to be responsible for the thruster performance and not Boeing.

In my experience writing control systems software, I have seen on many occasions excessive energy usage in the feedback loop of a dynamic system. Imagine you are trying to maintain a very specific orientation of the spacecraft. The sensors detect a slight drift, so you need to apply some energy to correct the drift. But if even a tiny bit too much energy is used then you need more energy to re-adjust. This can escalate quickly. I read somewhere that Boeing has a coarse attitude control, and a fine attitude control. No doubt they use the fine control when near the ISS, and my bet is that the control software wastes a lot of energy. That becomes heat and then you have a big problem with systems shutting down.

I wish I could have asked that question, what is the minimum amount of energy expected to maintain spacecraft control, and how much more energy did they see used in practice? And... do they even make those calculations?

[Comga]

NEAF Briefs- NEAF Talks now in 12 minutes or less.

Filmed April 2025

What’s the real story behind the Boeing Starliner problems. Boeing Technical Fellow Tom Mulder gives the inside details with this exclusive story of exactly what took place and what’s next for Starliner.

I just watched the entire presentation. My first impression is that the presenter admitted to no errors or issues from his team, after the software mistake was fixed. The blame instead was (very gently) placed on Butch Wilmore, or more precisely NASA flight test planning, for exercising the thrusters manually. Also, Aerojet Rocketdyne was indirectly blamed, insofar as they were presumed to be responsible for the thruster performance and not Boeing.

This
Tom Mulder must be a smart and capable guy, but this was a disreputable performance.
Completely skipping over the majority of issues
No new information
No explanation of any of the failures
No admission of how much money and time have been lost
No discussion of remediations
No status of ongoing work
No realistic discussion of Starliner’s future
The aforementioned blaming
Disappointing, to say the least

[woods170]

During one of the mission briefings it was mentioned that Starliner was kept at a particular solar attitude after launch for some technical reason, i.e. no Apollo-style BBQ-roll (aka Passive Thermal Control, PTC). It might very well be that this resulted in the cabin being permanently shadowed, and hence colder than anticipated.

Anyone remember the details of the briefing? It might have been mentioned in relation to the (over-) heating of the thrusters in the "dog house" which had been exposed to the largest amount of direct sunlight in the period between orbital insertion and docking.

That's some interesting detail and could explain the secrecy. Either they knew about expected problems with the thrusters and tried to avoid them by different orientation than during the test flight, or some additional failure happened which required this unusual orientation.

Emphasis mine.

Starliner is equipped with solar arrays on its "rear end". Pointing those directly towards the Sun puts the Crew Module (which is the "front end" of the Starliner) permanently in shadow, regardless of performing a "barbecue roll". Only by offsetting the angle towards the Sun by roughly 45 degrees (which is suboptimal for solar electric power generation) would a substantial half of the crew cabin be in direct sunlight again.

Crew Dragon don't have this issue because its solar arrays are conformal and cover half the trunk. Roughly pointing them towards the Sun already puts part of the crew module in direct sunlight.

Of note: Starliner was originally designed to fly without solar arrays, entirely operating on battery power. The rear-mounted solar arrays were a bit of an afterthought.