Rendering of a Portal Starburst spacecraft (front right), and a Supernova spacecraft (back left). Photo: Portal Space Systems

Portal Space Systems has raised $50 million in a Series A round to accelerate its progress building maneuverable spacecraft as the startup grows its team and expands manufacturing capacity. 

The raise comes at a critical time for Portal — the company just launched an in-orbit demonstration with Momentus to gain flight heritage on avionics systems including flight computer and power system. Portal was a customer on the Vigoride 7 vehicle, which launched on SpaceX’s Transporter-16 mission last week. 

Portal’s focus is on building spacecraft that can reposition and adapt to changing missions in orbit, underpinned by solar thermal propulsion technology. It is developing the Starburst ESPA-class rapid-maneuverability spacecraft, with the first one manifested on SpaceX’s Transporter-18 mission set for the fourth quarter of this year. This will be followed by the more capable Supernova, target for a 2027 debut. 

There’s a growing awareness of the need for maneuverability in space, Portal CEO and founder Jeff Thornburg tells Via Satellite. One inflection point was Space Force Gen. Michael Guetlein, vice chief of space operations, detailed China demonstrating “dogfighting” satellites in orbit last year.

“Both active and retired generals keep doubling down on why this is so important, especially U.S. Space Command and Gen. [Stephen] Whiting. All roads lead to being able to move more quickly and do it time and time again,” Thornburg said. “I think the defense customer understands how they want to employ it better, and they also understand that there’s limited options to be able to do that.” 

Geodesic Capital and Mach33 led the round. Booz Allen Ventures, ARK Investments, AlleyCorp, and FUSE also participated. 

Aaron Burnett, CEO of Mach33, noted this is the largest single check the firm has written. Mach33 is also invested in SpaceX and Stoke Space.  

“A world of 1.2 million planned orbital assets, adversarial on-orbit maneuvering by China and Russia, and orbital data centers requiring active thermal and positional management needs a propulsion architecture that delivers both speed and endurance,” Burnett and research associate Vlad Saigau wrote in a post explaining the investment. “We believe Portal occupies a structural gap in the propulsion market that the next decade of orbital operations will fill.” 

Travis Bales, director of Booz Allen Ventures, said in a statement that Portal addresses a “critical gap in orbital warfare.” Booz Allen’s previous space investments include Albedo, Quindar, and Starfish Space.

Thornburg said this funding round will support Portal growing its headcount and setting up a 52,000 square foot manufacturing facility the company will move into later this year. The new facility in Bothell, Washington, will support the move from development into production capability, with Thornburg saying it will be able to support 12 Supernovas and 16 Starburst once it’s up to speed. 

Portal is expanding its engineering and mission operations teams, as well as sales and supply chain roles. The company currently has about 40 employees and Thornburg expects to reach 80 or more by the end of the year. 

“In the last year, as we have made progress and de-risked the business, more and more defense agencies have come and seen what we’re doing here, and how we’ve de-risked the technology,” Thornburg said. “We’re trying to grow quickly into producing multiple spacecraft so that it’s not a science project — it’s actually a mission capability for them.”