Juno Propulsion is Advancing the First On-Orbit Demonstration of RDC-Powered Spacecraft Propulsion

Juno Propulsion, building the next-generation rocket propulsion with rotating detonation combustion, led by Alexis Harroun and Ari Martinez, has announced the successful close of a $1.4 million pre-seed financing round led by SOSV, with participation from Hypernova Fund, Leslie Ventures, Activate, Collaborative Fund, Safar Partners, and Cape Fear Ventures.

The funding will accelerate development and flight qualification of Project IRIS, Juno’s rotating detonation combustion (RDC) propulsion system. The company is targeting the first in-orbit demonstration of RDC-powered spacecraft propulsion in Q1 2027.

Project IRIS: High-Performance, Non-Toxic Propulsion.

Project IRIS is a 45-newton spacecraft propulsion system that uses non-toxic propellants, nitrous oxide and ethane. The system is designed to provide roughly 100 meters per second of delta-v while delivering performance that exceeds current chemical propulsion technologies.

Juno's rotating detonation combustion architecture has demonstrated higher efficiency than conventional combustion systems, offering the potential for greater performance with a simpler propulsion design.

The project is also backed by NASA through its TechLeap Prize program. In 2025, Juno was selected as one of ten winners of NASA’s Space Technology Payload Challenge, receiving $500,000 in funding to support the mission and its upcoming in-orbit demonstration.

Transitioning From Development To Flight.

According to Alexis Harroun, the funding marks a key step in Juno’s transition from ground-based testing to flight hardware and mission execution.

He said Project IRIS will provide an opportunity to demonstrate rotating detonation combustion technology in space for the first time, validating a new propulsion architecture that could enable higher-performance and more efficient spacecraft propulsion systems in future missions.

Building Next-Generation Spacecraft Propulsion.

Founded by Alexis Harroun and Ari Martinez, Juno Propulsion is developing spacecraft propulsion systems based on rotating detonation combustion (RDC), a technology designed to extract more energy from chemical propellants than traditional combustion methods.

The company believes RDC can enable a new generation of more efficient, high-performance propulsion systems for both commercial and government space missions.

Since receiving support through NASA’s TechLeap program, Juno has expanded its team and established an in-house propulsion testing facility in Tukwila, Washington, giving it the capability to develop, test, and qualify propulsion systems as it prepares for its first orbital demonstration mission.

Investor Confidence In Advanced Propulsion.

Andy Gollach emphasized the strategic importance of propulsion technology for both space and terrestrial applications, describing it as a key enabler of future technological capabilities.

He highlighted Juno Propulsion’s progress in developing rotating detonation propulsion systems and said the firm’s investment reflects confidence in the company's technology and its ability to advance next-generation spacecraft propulsion.

Preparing For Flight And Future Missions.

The new funding will support continued development, testing, integration, and mission preparation for Project IRIS ahead of its planned 2027 launch.

Juno also plans to expand its engineering team and capabilities as it advances rotating detonation combustion technology toward broader commercial and government spacecraft applications.