Announcing a major leap forward in space propulsion technology, RocketStar Inc. is introducing its FireStar Drive, a new electric drive system for spacecraft that makes use of nuclear fusion to augment pulsed plasma propulsion. In other words, aneutronic nuclear fusion in a water-fueled pulsed-plasma thruster holds great performance improvements through high-speed protons from ionized water vapor. These high-velocity protons, on impact, cause fusion with the nuclei of boron to produce very-high-energy carbon, which in turn decays into alpha particles that augment the thrust.
First discovered during the fusion technique’s SBIR Phase 1 project with AFWERX, it was noted that alpha particles and gamma rays were created when boronated water was introduced into the pulsed plasma thruster’s exhaust. Further validation occurred at the High Power Electric Propulsion Laboratory (HPEPL) in Atlanta, Georgia, during an SBIR Phase 2 project that boosted the propulsion unit’s thrust by 50%.
According to Adam Hecht, a professor of nuclear engineering at the University of New Mexico, RocketStar’s innovation is that the exhaust of the thruster includes a fusion-fission reaction, which represents a technological leap. Chris Craddock, the CEO of RocketStar, mentioned that the concept was initially developed in collaboration with Wes Faler of Miles Space—now RocketStar’s CTO after the acquisition of the company by Rocketstar. It has evolved into this fusion-enhanced thruster that touts eye-popping performance improvements.
RocketStar is ready to deliver the M1.5 thruster to customers and will conduct demos in space in July and October on an OTV ION Satellite Carrier by D-Orbit, launched by SpaceX Transporter missions. This cooperation put D-Orbit’s Matteo Lorenzoni in high spirits regarding the impending performance test in orbit.
Further plans include intensive ground testing and in-space demonstration of the FireStar Drive, scheduled for February 2025, on Rogue Space System’s Barry-2 spacecraft. Brent Abbott at Rogue Space Systems says he is looking forward to testing the new type of thruster and its future mission potential.
The FireStar™ family of thrusters runs a pulsed electrostatic cycle to allow for a myriad of Earth-orbiting and deep space missions using water propellant. Results of tests indicate that water’s vapor pressure and its plasma speciation are uniquely useful for this operating cycle. The FireStar™ Foundation Drive includes a plasma formation region with spark electrodes, two exhaust ports ringed by acceleration electrodes, and a single power supply providing spark and acceleration power.
The vapor enters an area of plasma formation and then expands toward the exhaust ports. Paschen’s law ensures that a spark will occur within the vapor when the supply voltage and pressure fall along the Paschen curve. High voltage electrodes surround each exhaust port, focusing and extracting positive ions and electrons from the plasma. As these are of unequal mass, electrons leave the plasma first and a thrust is created, which in turn creates a virtual cathode that pulls the remaining ions. It means that kinetic energy is obtained by the ions through the acceleration electrodes and the virtual cathode, increasing their thrust density above the Child-Langmuir limit. When the exiting ions meet the returning electrons, plasma neutrality is obtained, and it will appear as a white-hot ball in water vapor because of the multiple ion species with differing velocities.
Resonance occurs between the input pressure of the gas, resistive push-back from the spark, and the plasma drain rate, which is varied by the changing supply voltage. As illustrated below, the FireStar™ Foundation Drive employs geometry specifically configured to reinforce this resonance, minimizing wear, reducing the complexity of power supplies, and flight computing demands. These thrusters have produced thrust using a wide array of gases, including water vapor, Xenon, Argon, Krypton, Iodine, and air.
In the final analysis, RocketStar’s FireStar Drive is a new and remarkable advancement in the technology of space propulsion that offers very potent, fusion-enhanced capability for future space missions.