Rendering of Portal Space Systems’ Supernova multi-role, transorbital spacecraft. Photo: Portal Space Systems

Startup satellite developer Portal Space Systems on Thursday said it raised $17.5 million in an oversubscribed seed round that will support the full-scale demonstration of its Supernova multi-role, transorbital spacecraft expected to launch in 2026.

The funding raise builds on an undisclosed pre-seed round when Portal was created in November 2021, and $5.5 million in various Small Business Innovation Research Contracts awarded by the Space Force, including for tactically responsive space. The Seattle-based company emerged from stealth a year ago.

The round was led by AlleyCorp, with participation from Mach33, FUSE, First In, TFX, Offline Ventures, Atypical, and other strategic investors.

Supernova is headed for a critical design review this quarter followed by full-scale propulsion testing of the 3D-printed Hex Thruster, which enables dynamic space operations, including transorbital maneuvering.

Portal says that Supernova will be able to transfer from Low-Earth Orbit (LEO) to Medium-Earth Orbit in minutes, from LEO to Geostationary Orbit (GEO) in hours, and from LEO to cislunar space in days.

Systems integration of the spacecraft is slated for the fourth quarter and launch of the first demonstration mission is expected in mid-2026.

Once first flight is accomplished, Portal said it plans to scale production to support a fleet of its multirole Supernova spacecraft. The company touts its software-enabled payload flexibility to enable rapid payload swaps for defense and commercial customers.

The refrigerator-size Supernova bus weighs just over 1,300 pounds with fuel. Its multirole capability can accommodate payloads such as communications for a mobile communications relay system or a camera for surveillance roles.

Hex Thruster, which was designed by Portal, is heated by the sun to help power the company’s proprietary solar thermal propulsion system for long-range mobility.

“Our vision is to provide next-gen spacecraft that today’s space operations demand and our nation deserves,” Jeff Thornburg, Portal’s CEO, said in a statement. “This funding is testament to the increasing recognition that maneuverability at will is the critical need in both defense and commercial space operations. Supernova is the first spacecraft to deliver the performance of nuclear thermal propulsion without the burden of launching a reactor.”

This story was first published by Defense Daily