Halen Mattison left SpaceX because Elon told him his vision was too long-term. He wanted to build the propellant infrastructure that would unlock Mars and everything between here and there, but the timeline didn't fit SpaceX's roadmap. So he started General Galactic to do it himself.

His team is developing Genesis, a water electrolysis propulsion system that delivers hydrazine-level thrust and xenon-level efficiency using the safest, cheapest, most abundant propellant in the solar system. The company is targeting an orbital demonstration in 2026, with a long-term vision to operate refueling depots from LEO to Mars.

Inside the episode:

• Why the space industry's fear of new technology is creating a sitting-duck opportunity
How water electrolysis unlocks both near-term mobility services and long-term ISRU infrastructure
What "specific impulse" actually means for mission economics and why it matters more than people think
The Starship refueling challenge and why cryogenic propellant depots will work at scale
Sequencing from mobility-as-a-service to lunar fuel production to gas stations on Mars
Why consensus-following investors miss the most ambitious bets and how to tell the contrarian story

• Chapters •

00:00 – Intro
01:11 – When did Halen decide to start his own company?
02:18 – What did Halen do at SpaceX?
02:59 – Deciding moment to devote to a career in aerospace
05:16 – The current state and trajectory of Starship
07:53 – What is General Galactic building?
09:50 – General Galactic's products and end goals
12:12 – General Galactic's perspective shift on mobility in space
16:31 – Architecture vs the current market offerings
21:39 – Why is now the time to build a water electrolysis system?
24:27 – Genesis
25:42 – Hardware in space
26:19 – What would a General Galactic demonstration mission look like?
27:13 – What would product 1 look like?
28:15 – Mission capability unlocks and cost advantage
30:56 – Offering a service
31:27 – Origin and evolution of General Galactic
34:59 – Space companies that sequence well outside of SpaceX
36:06 – 4-year prediction if mobility gets adopted
38:39 – Misunderstandings about Starship's refueling logistics
42:01 – Where would General Galactic fit in the Starship ecosystem?
43:25 – What a v0.1 Mars gas station would look like
44:46 – How difficult is it to protect General Galactic's position with water electrolysis?
46:22 – Lessons from being a founder
49:30 – Sequencing

• Show notes •

General Galactic’s website — https://gengalactic.com/
Halen’s socials — https://x.com/HalenMattison
Mo's socials — https://twitter.com/itsmoislam
Payload’s socials — https://twitter.com/payloadspace / https://www.linkedin.com/company/payloadspace
Ignition’s socials — https://twitter.com/ignitionnuclear /
https://www.linkedin.com/company/ignition-nuclear/
Tectonic’s socials — https://twitter.com/tectonicdefense / https://www.linkedin.com/company/tectonicdefense/
Valley of Depth archive — Listen: https://pod.payloadspace.com/

• About us •

Valley of Depth is a podcast about the technologies that matter — and the people building them. Brought to you by Arkaea Media, the team behind Payload (space), Ignition (nuclear energy), and Tectonic (defense tech), this show goes beyond headlines and hype. We talk to founders, investors, government officials, and military leaders shaping the future of national security and deep tech. From breakthrough science to strategic policy, we dive into the high-stakes decisions behind the world’s hardest technologies.

Payload: www.payloadspace.com
Ignition: www.ignition-news.com
Tectonic: www.tectonicdefense.com

Railroad to Mars, with Halen Mattison (CEO of General Galactic)

Valley of Depth