Helios
In Development
Impulse Space
Overview
High-energy kick stage powered by a single Deneb methalox engine, designed to take payloads from a medium-lift rocket's low Earth orbit drop-off to GEO, translunar injection, or Earth escape without waiting months on electric propulsion.
Not yet flown. Impulse expects Helios's inaugural launch in 2027, the same vehicle that will carry a Mira to geosynchronous orbit on the Space Force's VICTUS SURGO mission. It is designed to be compatible with Falcon 9, Falcon Heavy, Starship, New Glenn, and Vulcan.