Portal Space Systems

Overview

Portal is building the Supernova and Starburst spacecraft, which use sunlight-heated propellant to make large orbit changes quickly. Founder Jeff Thornburg helped lead development of SpaceX's Raptor engine.

Funding

At least: $17.5M seed (2025) and a $50M Series A (Apr 2026).

Disclosed funding is the sum of publicly reported rounds found in the sources below. It is a floor, not a complete total.