Portal Space $50M Series A

Satellites usually go where a rocket drops them off and then make only small course changes. Portal Space Systems just raised $50 million to build spacecraft meant to move around much more aggressively once they are already in orbit. (spacenews.com) Portal announced the Series A on April 9, 2026. Geodesic Capital and Mach33 led the round, with Booz Allen Ventures, ARK Invest, AlleyCorp, and FUSE also participating. (portalsystems.space) The company is based in Bothell, Washington, and says the money will help it scale development, add staff, and open a 52,000-square-foot manufacturing facility later this year. Portal founder and chief executive Jeff Thornburg previously worked at SpaceX. (satellitetoday.com) The basic problem Portal is chasing is orbital mobility: the ability for a spacecraft to change altitude, plane, or mission after launch instead of staying on a fixed path. Portal says that matters as low Earth orbit, medium Earth orbit, and geostationary orbit get more crowded and operators want satellites that can reposition and keep working longer. (portalsystems.space) Portal’s nearer-term vehicle is called Starburst, an Evolved Expendable Launch Vehicle Secondary Payload Adapter-class spacecraft sized for rideshare launches. The company said in November 2025 that Starburst-1 is booked on SpaceX’s Transporter-18 mission in the fourth quarter of 2026. (portalsystems.space) Portal says Starburst-1 will spend a year in sun-synchronous orbit and demonstrate rendezvous and proximity operations, rapid retasking, and rapid orbital changes with two payload partners, TRL11 and Zenno. Portal has targeted about 1 kilometer per second of total delta-v, the standard measure of how much maneuvering a spacecraft can do. (portalsystems.space) The larger vehicle, Supernova, is designed for bigger moves between orbital neighborhoods. Portal said Supernova is aimed at transitions from low Earth orbit toward cislunar space, with a 6-kilometer-per-second-class maneuvering profile and shared subsystems with Starburst. (portalsystems.space) Portal’s pitch depends on solar thermal propulsion, which uses sunlight to heat propellant and produce thrust. Thornburg told National Defense in August 2025 that the approach could move a spacecraft from low Earth orbit to medium Earth orbit in two to three hours, from medium Earth orbit to geosynchronous orbit in about half a day, and from low Earth orbit to geostationary orbit in about a day. (nationaldefensemagazine.org) The defense market is a big part of the story. Via Satellite reported that Thornburg pointed to public warnings from United States Space Force leaders about Chinese satellite “dogfighting,” and Booz Allen Ventures said Portal addresses a “critical gap in orbital warfare.” (satellitetoday.com) Portal is also trying to show it can fly hardware before Starburst’s first free-flying mission. The company told Via Satellite it recently launched an in-orbit demonstration on Momentus’ Vigoride 7 to gain flight heritage for avionics including its flight computer and power system, and Momentus said Vigoride 7 launched on SpaceX’s Transporter-16 mission on March 30, 2026. (satellitetoday.com) (businesswire.com) The next test is whether Portal can turn that financing into flight hardware on schedule. Its public roadmap now points to Starburst customer missions in 2027, after the Starburst-1 demonstration planned for late 2026. (portalsystems.space)