Apollo Fusion is led by two rocket scientists, co-founders Mike Cassidy and Ben Longmier.

Mike Cassidy, CEO and co-founder

Mike was the CEO and co-founder of four successful startups and was previously a Vice President at Google where he led Project Loon, a high-altitude balloon telecommunications product. He has two degrees in Aerospace Engineering from MIT.

Ben Longmier, CTO and co-founder

Ben holds advanced degrees in Physics, Nuclear Engineering, and Plasma Physics, is a former professor of Aerospace Engineering at the University of Michigan, and was the founder and CEO of an aerospace company which was acquired by Apple.

Hall Effect Thruster experience

Mark Hopkins, Vice President

An expert in Hall thruster systems, Mark earned his PhD researching novel Hall thruster propellants under a fellowship from the National Science Foundation. He has 10 years of experience developing space systems from concept to flight hardware production.

Dean Massey, Director of Research

Dean's doctoral research focused on Hall thrusters and novel propellants, and the knowledge he gained allowed him to spend more than a decade leading research teams in the areas of plasma chemistry, materials science, fusion, and oil and gas. He brings his unique perspective to electric propulsion and state of the art facilities design and construction.


The Apollo Fusion team also includes domain experts in nuclear physics, plasma physics, and propellants, in addition to aerospace, electrical, mechanical, software, and nuclear engineering. The team has over 100 years worth of Hall thruster experience and is based in Silicon Valley.

100+ Years of Hall Thruster Experience
20 Team members
12 Full time employees
6 Former Googlers
5 PhD's
8 Propulsion labs built or rebuilt
15 Propellants tested
6 Generations of ACE


The plasma technology we've used in ACE is similar to the technology we've explored for fusion power. We believe this technology can become the foundation for a revolutionary hybrid power plant to serve safe, clean, and affordable electricity to everyone.

What can ACE do for your constellation?

Reach out to us at info@apollofusion.com and let's talk.