Apollo Fusion Inc. has been selected as the electric propulsion system for Spaceflight Inc.'s Sherpa-LTE. The Sherpa-LTE is a high specific impulse (Isp), xenon propellant, electric propulsion orbital transfer vehicle (OTV). It builds on Spaceflight's Sherpa-NG program by incorporating Apollo Constellation Engine (ACE) – a low thrust, high efficiency, radiation hardened Hall thruster propulsion system developed by Apollo Fusion. As ACE systems can generate more than 6km per second of delta-V, Sherpa-LTE now has the capability to deliver customers to GEO, cislunar, or Earth-escape orbits. Sherpa-LTE provides a low-cost alternative to purchasing full direct-inject launch vehicles and will extend the ability of small launch vehicles that are currently under development to reach beyond low Earth orbit. The Sherpa-LTE is targeted to fly mid-2021.
Apollo Fusion, Inc. designs and builds state of the art Hall thruster propulsion systems for a variety of government and commercial satellite programs. Apollo's founder and CEO is Mike Cassidy. He was previously a Google vice president where he led Project Loon, a high-altitude telecommunications system.