Rubicon Space Systems is proud to announce that, alongside Outpost Technologies, we have been selected for a Phase II AFWERX SBIR award to advance a fast-response fueling system for ASCENT (AF-M315E) propellant.

The award builds on a successful Phase I effort and brings total program funding to approximately $2.1 million. Together, Rubicon and Outpost are developing a capability designed to help spacecraft operators fuel and launch on dramatically compressed timelines—an increasingly important requirement for Tactically Responsive Space (TacRS) missions.

Traditionally, spacecraft fueling operations can require specialized facilities, extensive safety infrastructure, and long preparation schedules. ASCENT propellant offers a safer, lower-toxicity alternative to legacy fuels, creating an opportunity to simplify those operations and reduce the time required to prepare spacecraft for launch.

During Phase I, the team designed and demonstrated a prototype fueling system capable of supporting rapid spacecraft fueling in an operationally relevant environment. The success of that effort led directly to the competitive Phase II award.

Over the next 18 months, Rubicon and Outpost will mature the system into production-ready hardware and deliver three complete fueling systems. The program will culminate in an operational demonstration validating the capability for real-world responsive space missions.

Rubicon's role in the effort draws on years of experience developing ASCENT propulsion systems and supporting spacecraft integration, fueling operations, and ground support equipment. By combining propulsion expertise with Outpost's manufacturing and operational capabilities, the team is creating a practical solution that can be deployed where and when customers need it.

Beyond the government mission, the program also supports a broader commercial vision: fueling as a service.

As launch timelines continue to shrink and satellite operators seek more flexible mission options, many organizations will prefer access to fueling capabilities without investing in dedicated fueling infrastructure. Rubicon sees a future where ASCENT fueling can be delivered as a mobile, turnkey service—allowing spacecraft operators to focus on their mission while trusted experts handle propellant loading safely and efficiently.

"We believe responsive space requires responsive ground operations," said Daniel Cavender, Director of Propulsion at Rubicon Space Systems. "This program is helping establish the technical foundation for a future where ASCENT-fueled spacecraft can be prepared for launch faster, more safely, and with far less infrastructure than traditional approaches."

Rubicon is grateful to AFWERX, AFRL, and Outpost Technologies for their partnership and support. We look forward to sharing progress as the program advances toward operational demonstrations and future commercial services.

For more information about Rubicon's ASCENT propulsion systems and fueling capabilities, contact us at info@rubicon.space.

Image: Artist's Rendering