spacex-alum
(3)
Halen Mattison
Halen Mattison is the co-founder and CEO of General Galactic, an El Segundo space-propulsion company building Genesis, a water-fueled engine that aims to combine hydrazine-level thrust with xenon-level efficiency. A former SpaceX engineer who worked on propellant generation for Starship, he left after being told his Mars-fuel vision was too long-term, studied at Stanford, and started the company to build the propulsion and propellant infrastructure he believes will become a railroad to Mars. The company raised roughly $9.9M across pre-seed and seed rounds and first emerged converting CO2 into methane on Earth before sharpening its focus on high-agility spacecraft and water-based propulsion.
Arc
Arc is a Los Angeles electric boat company building battery-powered watercraft from the ground up - software, motors, battery packs and hulls - rather than retrofitting gas boats. Founded in 2021 by veterans of SpaceX, Rivian and Tesla, Arc started with the high-end Arc One, found its commercial footing with the Arc Sport electric wake boat and the Arc Coast center console, and is now extending its propulsion stack into commercial and defense vessels including electric and hybrid tugboats. The pitch: quiet, fume-free, low-maintenance boats with the torque and software experience of an EV.
Laurence Allen
Laurence Allen is the co-founder and CEO of Terranova, a Berkeley-based startup building autonomous terraforming robots that lift flood-prone land out of harm's way by injecting wood waste slurry deep underground. A UC Berkeley Mechanical Engineering graduate (2024) who conceived the idea during a 2021 SpaceX internship, Allen launched the company — originally called Levitree — to save his own hometown of San Rafael, California, which floods to waist depth several times a decade. Terranova closed a $7M seed round in late 2025 at a $25.1M valuation led by Congruent Ventures and Outlander, and can lift one acre of land by one foot per day at a fraction of the cost of traditional seawalls. Allen was named to the 2026 Forbes 30 Under 30 list in Energy & Green Tech, took a leave from his Stanford master's program to scale Terranova full-time, and entered 2026 actively pursuing commercial elevation projects across the Bay Area for flood prevention, development, and wetland restoration.