Portal Space Systems

Portal Space Systems is a Bothell, Washington-based spacecraft manufacturer developing Supernova, a maneuverable, solar-thermal spacecraft engineered for sustained delta-v, on-demand taskability, and cross-orbit mobility from LEO to cislunar space. The company was founded in 2021 by Jeff Thornburg (former propulsion executive at SpaceX and Amazon Project Kuiper), Ian Vorbach, and Prashaanth Ravindran.

Supernova is built around Solar Thermal Propulsion (STP), an architecture that concentrates sunlight using deployable, re-stowable mirror concentrators onto a compact thermal receiver, generating heat comparable to a compact nuclear reactor. The concentrated heat loads a thermal battery and drives a proprietary HEX Thruster -- a 3D-printed, single-piece heat exchanger/nozzle with no internal interfaces or moving parts -- producing sustained thrust from a safe, storable monopropellant.

This architecture delivers roughly 6 km/s of delta-v, on-standby taskability in minutes, and payload swap capability in under 24 hours, enabling repeated maneuvering between LEO, MEO, GEO and cislunar space over a multi-year operational life. Target use cases span national security (rapid response, space domain awareness, cislunar logistics), science and exploration (lunar insertion, orbital repositioning), and commercial operations (constellation maintenance, life extension, debris mitigation).

Portal has raised over $20M in venture funding, including a 2025 seed round led by AlleyCorp, a $45M Strategic Funding Increase (STRATFI) from the U.S. Space Force, and state grants supporting expansion of its Bothell manufacturing and test facilities. The company has partnered with Paladin Space on commercially structured debris-removal infrastructure, with Starlab as an early partner.