UNIFIED THRUSTER ARCHITECTURE V12
ELECTROMAGNETIC HYDROGEN PROPULSION UNIT FOR GATEWAY: UNIFIED THRUSTER, REMN, SNAPBACK, BAFFLE, AND GTRU ARCHITECTURE
AEMS electromagnetic architectures are available for commercial licensing and technical collaboration. Intellectual-property rights remain with AEMS LLC. Confidential technical review is available under NDA and defined scope.
ABSTRACT
The H₂EM Thruster is an EM-governed hydrogen combustion propulsion unit with downstream electromagnetic plume augmentation. This paper presents the thruster as a drop-in replacement for the Hall thruster and chemical engine combination currently planned for cislunar operations, then extends the architecture to the full interplanetary configuration.
Part 1 specifies a single-engine lunar demonstrator: one H₂EM combustion/plasma core, one REMN (Rotating Electromagnetic Nozzle), and one GSB-REMN AB snapback module with terminal baffle. Primary power is a 1,000 kg Sr-90 GTRU (Governed Thermal-Electric Retention Unit) delivering 115–138 kW electric continuously with no solar arrays, no eclipse constraints, and no deployment mechanisms. Propellant is water at effectively zero cost, replacing 5,000 kg of xenon at US$4–6M. At projected architecture targets, the single-engine configuration delivers 200–400× the exhaust velocity of the Hall thruster state of the art (AEPS/HERMeS) on the same power class, with zero electrode erosion, zero stored-gas hazard, and governed acceleration for crewed platforms.
Part 2 scales the architecture to a 2×2 engine cluster with twin REMN nozzles and Prometheus-class fission power for interplanetary deep-space transit.
TABLE A1: SINGLE-ENGINE DEMONSTRATOR CONFIGURATION
| PARAMETER | SPECIFICATION |
|---|---|
| Engine core | Single H₂EM combustion/plasma core |
| REMN nozzle | Single GSB-REMN AB snapback module with terminal baffle |
| Power source | Sr-90 GTRU (1,000 kg, 115–138 kW electric, 28-year life) |
| Propellant | Water (H₂O), ~2,500 kg for full cislunar Δv |
| Propellant cost | Effectively zero (vs US$4–6M for AEPS xenon) |
| Combustion Isp | ~350–400 s |
| Cruise Isp (plasma/REMN) | ~10,000 s |
| Burst Isp (REBCO + GSB) | 600,000–1,200,000+ s (projected; pending Stage 2b validation) |
| Burst v_e | 6,000–12,000+ km/s |
| Electrode erosion | Zero (wall-less EM nozzle) |
| Stored-gas hazard | None (water propellant) |
| Governance | DIGSP with governed acceleration for crewed platforms |
POWER ARCHITECTURE: Sr-90 GTRU
The demonstrator is powered by a 1,000 kg Sr-90 GTRU delivering 460 kW thermal and 115–138 kW electric via governed Stirling conversion at 25–30% efficiency. Sr-90 (strontium-90) has a half-life of 28.8 years, a specific thermal output of 0.46 W/g, and is available in multi-tonne quantities as a fission waste product from reprocessing facilities at Hanford (USA) and Sellafield (UK). At 115–138 kW electric, the GTRU provides 15–40 kW margin above the single-engine cruise cracking requirement (75–100 kW), covering EM coil excitation (~50–80 kW), DIGSP overhead (~5 kW), and system losses.
The GTRU eliminates every failure mode associated with solar array propulsion architectures: deployment jams, eclipse gaps, micrometeorite accumulation, radiation degradation, thermal cycling fatigue, pointing constraints, and panel flutter during high-thrust burns. The engine fires in any attitude, at any point in the orbit, without power management, available 100% of the time for the full 28-year GTRU life.
PROPELLANT: WATER AT ZERO COST
In plasma/REMN cruise mode at Isp ~10,000 s, the propellant mass for a full cislunar Δv budget of ~6 km/s is minimal. For a 40,000 kg Gateway-class platform: mass ratio MR = e^(6,000/98,000) = 1.063. Propellant fraction: 6.3%. Propellant mass: ~2,500 kg of water. The Gateway AEPS Hall thrusters require approximately 5,000 kg of xenon at US$850–1,200/kg, for a propellant cost of US$4.25–6.0M. The H₂EM demonstrator replaces this with 2,500 kg of water at effectively zero cost. Future ISRU (In-Situ Resource Utilisation) lunar water extraction eliminates Earth-supply dependency entirely.
LICENSABLE SYSTEM
Unified Thruster Architecture V12
Published architecture, system, model, or governed-field design