#701 – Electric Propulsion with Todd Bailey

Aug 22, 2025

Todd Bailey, an engineer at Muon Space with a rich background in electric propulsion, shares insights into the evolution of rocket technology. He discusses the challenges and triumphs of transitioning from major corporations to startups in the aerospace industry. The conversation delves into innovative uses of zinc as a propellant in Hall effect thrusters, and the importance of mentorship and resilience in navigating high-stakes decisions. Bailey also reflects on the influence of science fiction on real-world technological ambitions, particularly the legacy of Zefram Cochrane's warp drive.

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ADVICE

Pick Jobs That Teach And Reward

Choose jobs that are at least two of: fun, lucrative, or teach you something.
Prioritize roles with strong people you can learn from to accelerate skill growth.

INSIGHT

Requirements Force Useful Clarity

Requirements-driven design feels tedious at first but forces clarity on what matters.
Defining clear goals prevents wasted engineering cycles on unimportant details.

ADVICE

Optimize For System Impact

Focus engineering effort on whatever most helps the whole system, not marginal specs.
Prioritize maintainability, testability, and shipping over tiny accuracy gains beyond requirements.

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Welcome back Todd Bailey of Starlight Engines, now Muon Space! (11 years later)

Todd was on Episode 194 of The Amp Hour, when he was consulting in the art and design space and building instruments like Where the Party At (WTPA). He was designing ‘robot doors’ for Calvin Klein’s house, discussed last time.
Through Andy Reitano, Todd learned about a role at Lockheed Martin (a US defence company) working on sonar for submarines.
“What a good job is”
- Fun
- Lucrative
- Skills / teach you
Todd, Andy, and other Lockheed Martin friends worked on the VEC9 discussed in ep194
Clearance was required to work on sonar
Military electronics had some differences from his past work, but Todd was interestingly complementary of requirements driven design / waterfall
Chris and Todd were hanging out in a bar before he moved over to working on space and Todd mentioned he wanted to be Zefram Cochrane and do interesting things that matter (in space).
Star Trek First Contact (gah, I said generations)
Past guest Shawn Meehan talked to Todd and that’s how he started working at the “stealth space startup” at the time
Astra
HBO (not Netflix) special called Wild Wild Space
Other past guests of the show who were at Astra include Charles Aylward and Jeri Ellsworth
Silicon Valley Startup
“When the heavens went on sale” (book)
Commercial space by SpaceX
Rocket Lab was second
“Fail on stage”
Booster state of that rocket motor control
Electric turbo pump
Delphin engine
Cryogenic / feedback was hard
Alameda indoor test facility
Meant to fit in shipping container (8×8.5×40 ft)
System design and market requirements (launches don’t want small rockets)
Working remote
No place like home Jim Williams essay
Leaving Astra
Staying in the trenches
Rocket Lab
3rd stage “Kick stage, now known as “Photon“
Things you can work on in space
- Radios
- Sensors
- Power
Electric propulsion (EP)
Apollo fusion – Alex Zannos (Contemporary) and Mike Cassidy (CEO)
After working on fusion didn’t have legs, they switched to working on Hall effect thrusters
“Low earth orbit is 50% of the way to anywhere in the solar system”
Rocket equation
Stage fires then falls off
Kick stage is 3rd stage
Accelerating an ion beam
Delta V book
Rocket efficiency
“Seconds of ISP” How much mass do you use to go distance
Asteroid mining
Who buys EP?
SpaceX built their own Argon thruster
Torque rods / reaction wheels
Apollo successfully pivoted
Acquired by Astra space / finished the apollo constellation engine
In 2022, Todd and his cofounder Mark Hopkins started Starlight Engines after some initial proof points and then fundraising
Had opinions about EP
Goebels and Katz textbooks about EP
Busek electric propulsion is a family business that has tried all kinds of EP. Run by Vlad Ruby & son Pete.
Starlight is based on solid Zinc propellant
Traditionally it’s Xenon
“The honda civic of hall effect sensor systems”
The atomic mass of Zinc is light
“Lickable EP”
Discharge converter runs the ion beam
Custom magnetics
300W – 800W
28V spacecraft bus
“Plume divergence”
Need to go from solid to gas
Cathode is a thermionic emitter “Like a tube amp”, it emits to boil off electrons
Zinc gets caught in electron cloud, knocks an electron off to make ions, ejected from a positively charged plate nearby.
Novel propellent is a differentiator
Starlight had a scrappy factor, like they built their own vacuum chamber (for 15K!)
The device is not known to be operational in space yet (they sell it but don’t operate it, so it’d be tough to know)
“Give the first one away”
Have sold 4 propulsion systems
Muon space needed a propulsion system and instead decided to buy the company. They weren’t put off by “two guys in a garage and contractors”.
Muon builds things like fire detection satellites
For more info about their past work and see pictures of the plumes, check out Starlightengines.com
To see the new things they’ll be working on, check out Muon space