B - PERFORMING OPERATIONS
B64 - AIRCRAFT
B64G - COSMONAUTICS
B64G1/422 - {Nuclear power generation}
G - PHYSICS
G21 - NUCLEAR PHYSICS
G21H - OBTAINING ENERGY FROM RADIOACTIVE SOURCES
G21H3/00 - Arrangements for direct conversion of radiation energy from radioactive sources into forms of energy other than electric energy, e.g. {into} light {or mechanic energy}
F - MECHANICAL ENGINEERING
F03 - MACHINES OR ENGINES FOR LIQUIDS
F03H - PRODUCING A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
F03H1/0037 - {Electrostatic ion thrusters}
B - PERFORMING OPERATIONS
B64 - AIRCRAFT
B64G - COSMONAUTICS
B64G1/405 - {Ion or plasma engines
F - MECHANICAL ENGINEERING
F03 - MACHINES OR ENGINES FOR LIQUIDS
F03H - PRODUCING A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
F03H1/0012 - {Means for supplying the propellant}
B - PERFORMING OPERATIONS
B64 - AIRCRAFT
B64G - COSMONAUTICS
B64G1/408 - {Nuclear spacecraft propulsion}