Tom Mueller | Sourcery Summary

Podcast: Sourcery | Participants: Molly O'Shea, Tom Mueller

1. Key Themes

In-Space Transportation is the Next Frontier After Launch

Mueller's core thesis is that launch is a solved (or near-solved) problem, and the massive untapped opportunity is moving cargo within space. He left SpaceX specifically because of this conviction.

"When I left, I had the plan of launch mostly being solved or being solved. It's like the next big opportunity is to move all that payload, all that cargo around in space. So I started Impulse Space to do in-space transportation as opposed to from Earth to space transportation." — Tom Mueller 00:08:34

Impulse's product suite reflects this: Mira (orbital transfer/maneuvering vehicle), Helios (high-energy transfer stage), and future lunar landers. Helios can improve payload to Mars by up to 5x and effectively adds a third stage to a two-stage rocket.

"It can take five tons of payload to the moon on a Falcon 9. It can improve your payload to Mars by up to a factor of five. Yeah. It basically adds a third stage to a two-stage rocket." — Tom Mueller 00:07:30

Vertical Integration + Rapid Iteration as Competitive Moat

Impulse has brought nearly every critical manufacturing capability in-house: CNC machining, 3D metal printing, COPV tank winding, valve assembly, and propulsion testing. This wasn't accidental — it was a deliberate strategy modeled on what Mueller saw work at SpaceX.

"Being extremely vertically integrated, having the machine shop right here with the assembly areas and just really rapid, rapid prototyping test area out back so we can build, assemble, test and iterate." — Tom Mueller 00:03:34

"We're basically the same plan, vertically integrated, hire the best and move fast. And that's what we learned at SpaceX." — Tom Mueller 00:41:45

COPVs alone were identified as a strategic chokepoint: "If you wanted to buy one of these, it might take a year or two to get them and be hundreds of thousands of dollars a piece." 00:16:42 — bringing them in-house removes that bottleneck entirely.

Space-Based Data Centers as Inevitable Infrastructure

Mueller is unambiguously bullish on orbital data centers, framing them not as a novelty but as a structural necessity driven by Earth's power constraints.

"Data centers in space are a no-brainer... All you need as an input is power, and all you have as an output is data. So you move it to space, you have all the power you would ever need, and you transmit that data back down on a laser beam, terawatt laser beam. So it's just, it's solved. It's just so simple." — Tom Mueller 00:38:54

"Power for compute is growing at greater than 15% per year. Some people say that it'll be equal to all of the Earth's base power right now in about 20 or 30 years... I think it's just important to move it up." — Tom Mueller 00:40:01

This macro tailwind directly benefits Impulse's in-space transportation business — more infrastructure in space means more payloads to move.

2. Contrarian Perspectives

The Moon is More Strategically Important Than Mars (Near-Term)

Contrary to the cultural narrative that Mars is the next great human destination, Mueller argues the Moon is the more important near-term priority — especially for resource extraction.

"I think the moon is more important than Mars in the near term. People are predicting we're going to run out of copper here in the next few years. We just, data centers require so much copper. We need to start getting copper from the moon or from the asteroids. There's an almost infinite supply in our solar system of material, enough to supply us for thousands of years. We just got to get ready to go get it." — Tom Mueller 00:43:07

This reframes lunar investment not as exploration romanticism but as resource necessity driven by terrestrial demand (AI/data center copper consumption).

3D Printing for Rocket Engines is a "Cheat Code," Not a Trend

While additive manufacturing gets talked about broadly in aerospace, Mueller makes the non-obvious claim that for rocket engines specifically, 3D printing is categorically superior — not just iteratively better.

"For rocket engines, it's almost like a cheat code. It's so easy to make a high-performance rocket engine with 3D printing. Because the rocket injectors and the cooling passages are pretty small and complex... With 3D printing, you just basically draw the fluid passages you want and then put a wall around it and just print it." — Tom Mueller 00:14:31

He also notes that castings — used by Raptor for large parts — simply cannot produce the fine injector geometries required for high-performance engines at small scale.

Nuclear Electric Propulsion Will Be Essential for Outer Planets — But Solar Wins Cis-Lunar

Against the binary "chemical vs. nuclear" framing, Mueller draws a nuanced boundary: solar electric will dominate near-Earth and cis-lunar missions as solar panels get lighter, but nuclear electric is the only viable option for outer planets.

"If you want to go to the outer planets where you get far away from the sun... with a big nuclear electric stage, you could actually get to Pluto faster because you got high performance and you could slow down and enter orbit around Pluto... you've still potentially have megawatts of power to do science for decades." — Tom Mueller 00:35:43

He essentially argues NASA's New Horizons was a wasted opportunity — nuclear electric would have enabled orbital science instead of a flyby.

Starlink's Success Was Obvious From the Inside — The "Naysayers" Were Simply Wrong

Mueller pushes back on the popular narrative that Starlink was a risky moonshot. From the inside, the ROI was clear early on, and the team was puzzled by external skepticism.

"It was really funny to see all the naysayers online saying there's no way they're going to be powerful... And we're looking at it going the other way, going to make them as fast as you can and launch them. This is going to hockey stick the stock, which it exactly did." — Tom Mueller 00:41:04

The implication: when insiders with full information are unanimously bullish and the market is skeptical, that gap is where alpha lives.

3. Companies Identified

Impulse Space In-space transportation company building orbital transfer vehicles (Mira), high-energy transfer stages (Helios), and future lunar landers. Founded by Tom Mueller (SpaceX propulsion lead). Has three spacecraft on orbit, completed a rendezvous mission, and is developing what Mueller claims will be the highest-performing hydrocarbon engine ever flown.

"We have three on orbit right now. We did a rendezvous last year between two of them. Got within 1,200 meters of each other, which is really damn close in space." — Tom Mueller 00:06:32

Vast (Space Station) Commercial space station company. Impulse Space provided the entire propulsion system for Vast, including thrusters and COPV tanks — validating Impulse as a propulsion supplier to emerging space infrastructure.

"The bigger one there is a tank for Vast space station. We provided the whole propulsion system for Vast, including the thrusters." — Tom Mueller 00:15:58

LeoLabs Commercial space object tracking company. Mueller specifically called them out as a reliable source of collision avoidance warnings — a critical service layer for the growing on-orbit economy.

"There's actually some commercial companies like LeoLabs that track things and they just tell you, hey, you've got a potential [collision]." — Tom Mueller 00:32:32

SpaceX Mueller's original home and the model for Impulse's operational philosophy. His description of SpaceX's internal culture around Starlink provides rare insider confirmation of their execution advantage.

"The key to success is having a great team... vertically integrated, hire the best and move fast. And that's what we learned at SpaceX." — Tom Mueller 00:41:45

4. People Identified

Tom Mueller Founding propulsion engineer at SpaceX; creator of the Merlin engine (the most reliable and highest thrust-to-weight rocket engine ever developed); led Starship propulsion for 6 years; now founder/CTO of Impulse Space. Self-describes as a better CTO than CEO — technically oriented, hands-on, and still building rocket engines in his garage for pre-production prototyping.

"My proudest development was the Merlin engine, which is currently flying on Falcon 9, the most reliable rocket engine ever developed and also the highest thrust-to-weight of any rocket engine ever developed." — Tom Mueller 00:08:08

"I like designing the rocket engines and the avionics and the radios and the telescopes... I'm very technical." — Tom Mueller 00:42:30

Jared Isaacman Named as NASA leadership signaling a bullish, action-oriented lunar strategy that aligns with Mueller's vision.

"Jared Isaacman said, we're going to build a base on the moon and we're going to stay there. And that's right on, man. That's exactly what I want to do." — Tom Mueller 00:42:38

Elon Musk Described by Mueller (who knew him from the amateur rocketry world before SpaceX) as an exceptional talent magnet and urgency driver — the "how" behind SpaceX's culture.

"Elon's great to work with. Generally, he just energizes you. He's got this infectious enthusiasm and gets you just hyped up to go do crazy stuff... He's also really good at finding and recruiting talent." — Tom Mueller 00:41:15

5. Operating Insights

Learn It Before You Hire For It

Mueller's approach to building COPV capability demonstrates a counterintuitive hiring sequence: acquire the machine and learn the craft yourself first, then hire domain experts. This builds institutional knowledge and avoids being dependent on talent that doesn't understand your specific context.

"Mostly it was guys that hadn't done it before. So we bought the winder and learned, and then we've since hired people who have run the winders before... We mostly learned. We had a consultant come in and show us how to design properly. And a lot of cut and try." — Tom Mueller 00:16:56

It Takes Three Iterations to Get to a Tight Product — Build That Into Your Timeline

Mueller has observed this pattern across two of the most successful rocket engines in history. Planning for three development cycles isn't pessimism — it's engineering realism that should inform roadmap and fundraising timelines.

"I always said it took three versions of Merlin to get it to be really tight. And it took three versions also of Raptor. I always say it takes really three iterations to get to a really, really tight product." — Tom Mueller 00:25:07

Modular Product Design Unlocks Both Demo and Custom Markets

Impulse's "pegboard" payload deck is designed to be reconfigured for specific missions — a one-size-fits-all version for hosted/demo payloads, and a mass-optimized version for dedicated missions. This architecture lets you serve multiple customer types from the same platform.

"This is like our demo flights where you can mount anything... If we have a specific mission where they just have one payload in the middle, we actually redesigned this to get rid of some mass. So it can be custom-fit to whatever your payload is." — Tom Mueller 00:22:47

6. Overlooked Insights

Photonic Chips as a Copper Scarcity Hedge — An Emerging Forced Transition

Mueller made a brief but highly significant observation: if copper becomes critically scarce (driven by data center demand), the transition to photonic chips stops being a technology choice and becomes a necessity. This wasn't explored by either speaker, but it has major investment implications.

"People are predicting we're going to run out of copper here in the next few years. We just, data centers require so much copper... I think we're going to have to flip to something else. I think it's going to drive that technology." — Tom Mueller [00:43:07 / 00:43:25]

This is a non-obvious second-order effect: AI infrastructure demand → copper scarcity → forced acceleration of photonic chip adoption. Companies building photonic interconnects and optical compute (e.g., Lightmatter, Ayar Labs) may be beneficiaries of a timeline compression that has nothing to do with their own roadmap execution.

Impulse Space is Quietly Becoming a Space Infrastructure Supplier, Not Just a Transport Company

The Vast propulsion contract is mentioned only briefly, but it signals something much larger: Impulse is already monetizing its technology as a B2B supplier to other space infrastructure players. This is a parallel revenue stream to their core transport business that wasn't discussed but has significant implications — it means they have a path to revenue that doesn't depend solely on their own vehicle launches.

"We provided the whole propulsion system for Vast, including the thrusters. And then the one that's getting wrapped there will be a very high-pressure helium tank for the Helios vehicle." — Tom Mueller 00:15:58

Combined with their in-house COPV production capability (which serves both internal and external needs), Impulse may be quietly positioning as the "propulsion and pressure vessel" supplier of choice for the broader commercial space ecosystem — a moat that compounds with every customer they serve.