Portal Space Systems has secured a $50 million Series A funding round to pioneer a groundbreaking high-power solar thermal rocket engine.
Founded in 2021 by Jeff Thornburg, a key engineer behind SpaceX's powerful Raptor engine, the startup aims to transform in-space propulsion.
Revolutionizing Orbital Mobility
The company's innovative Hex thruster combines a solar concentrator and nozzle to heat propellant using sunlight, offering superior performance over traditional chemical or electric systems.
This technology revives a NASA concept explored since the 1960s but shelved due to lack of demand, now vital amid surging satellite deployments and geopolitical tensions.
Investors including Geodesic Capital, Mach33, ARK Invest, and Booz Allen Ventures value Portal at $250 million, with additional $45 million from U.S. military strategic funding.
From NASA Labs to Orbital Dominance
Thornburg's experience at SpaceX, Stratolaunch, and Amazon's Project Kuiper positions Portal to mature solar thermal propulsion rapidly in orbit.
The engine enables satellites to maneuver swiftly, reducing collision risks in constellations potentially numbering millions and supporting military rapid repositioning against rivals like China.
Portal's SuperNova spacecraft, dubbed a 'fighter jet for orbit,' will demonstrate the prototype in 2027, following recent flight electronics launch and an October shakedown.
By proving components in space, Portal accelerates progress toward nuclear thermal propulsion without costly ground facilities.
Thornburg emphasized the urgency: "It’s no longer acceptable to move slowly on orbit... China’s running circles around our spacecraft."
This funding heralds a new era of high-power, efficient propulsion, potentially crowning Portal as a 'space mobility prime' for diverse users.
Alfred Lee
