A spacecraft propulsion system operated in the presence of an ambient flux of cosmic rays is provided, wherein the cosmic rays interact with deuterium-containing nuclear micro-fusion fuel material to generate products having useful kinetic energy. The propulsion system comprises a supply of the deuterium-containing particle fuel material, along with means (such as a gun) for projecting the material (e.g. as successive packages in the form of shell projectiles) outward from a spacecraft. The spacecraft has means (such as a pusher mechanism) for receiving at least some portion of the generated kinetic-energy-containing products to produce thrust upon the spacecraft.

Asteroid redirection and soft-landing systems are provided that use cosmic ray and muon-catalyzed micro-fusion. These systems include a micro-fusion propulsion system providing thrust for redirecting a small asteroid, as well as providing a particle cushion at a landing site for a soft-landing. The systems deploy deuterium-containing fuel material as a localized cloud interacting with incoming ambient cosmic rays to generate energetic fusion products. Dust or other particulate matter in the fuel material converts some cosmic rays into muons that also catalyze fusion. The fusion products provide thrusting upon the asteroid. The fusion products also aid deceleration of incoming asteroids to be mined for a soft landing upon a lunar or planetary surface.

Asteroid redirection systems are provided that use cosmic ray and muon-catalyzed micro-fusion. These systems include a micro-fusion propulsion system providing thrust for redirecting an asteroid, as well as micro-fusion electrical generation powering an ion drive. The systems deploy deuterium-containing fuel material as a localized cloud interacting with incoming ambient cosmic rays to generate energetic fusion products. Dust or other particulate matter in the fuel material converts some cosmic rays into muons that also catalyze fusion. The fusion products provide thrusting upon the asteroid, or when produced near turbines facilitates electrical generation, which can then power an ion drive.

A customizable thin plate fuel form and reactor core therefor are disclosed. The thin plate fuel will comprise a fuel material embedded within a matrix material, with the entire unit having a coating. The thin plate fuel may be flat or curved and will have flow channels formed within at least the top surface of the fuel plate. The structure of the thin plate fuel will make it easier for coating with Tungsten or any other suitable material that will help contain any byproducts, prevent reactions with the working fluid, and potentially provide structural support to the thin plate fuel.

A nuclear reactor has an axially stratified fuel bed. The reactor features a reactor shell having a base, a top having an exhaust outlet, and an axis. The axially stratified fuel bed is within the reactor shell, and includes: a first zone configured to operate at a first temperature T1, the first zone comprising a plurality of first fuel particles, each first fuel particle comprising a first radioactive ceramic core and a first ceramic seal coating; and a second zone configured to operate at a second temperature T2, where T2>T1, the second zone comprising a plurality of second fuel particles, each second fuel particle comprising a second radioactive ceramic core and a second ceramic seal coating. A coolant fluid flow path carries a coolant fluid from the base of the reactor to the exhaust outlet, along a flow path passing sequentially through the first zone and the second zone. The first ceramic seal coating has greater stability at T1 than at T2, and the second ceramic seal coating has greater stability at T2 than the first ceramic seal coating.

A nuclear fuel assembly for a nuclear reactor core, the fuel assembly having at least one fuel element including an elongated shell defining an interior volume, a lattice structure disposed within the interior volume, at least one flow channel extending through the lattice structure, at least one lattice site disposed in the lattice structure, and at least one fuel compact disposed within a corresponding one of the at least one lattice site, a first end cap including a boss having a first cross-sectional shape, the first end cap being affixed to a first end of the shell, and a second end cap including a first bore having a second cross-sectional shape, the second end cap being affixed to a second end of the shell, wherein the first cross-sectional shape of the boss is the same as the cross-sectional shape of the bore.

The invention is for a startup system for nuclear fusion engines in space. The combustion of hydrogen and oxygen produces heat that is used by a heat engine to produce electricity. This can be supplemented by electricity from other operating engines. The exhaust from the combustion is condensed and electrolyzed to produce hydrogen and oxygen once the engine is in operation. This provides a constant source of energy for future startups. The engine is started up at partial power in electricity generation mode and this power replaces the power from the combustion as it grows. The combustor uses the same heat engine as the nuclear engine uses for power generation.

Systems and methods for nuclear reactor direct drive of a cryocooler turbine. A nuclear thermal propulsion (NTP) system may have a nuclear reactor that heats a thermal working fluid for directly driving the turbine to power a cryogenic fluid management (CFM) system for keeping propellant at cryogenic temperatures. The features may be used on NTP rockets. The propellant may be liquid hydrogen.

A customizable thin plate fuel form and reactor core therefor are disclosed. The thin plate fuel will comprise a fuel material embedded within a matrix material, with the entire unit having a coating. The thin plate fuel may be flat or curved and will have flow channels formed within at least the top surface of the fuel plate. The structure of the thin plate fuel will make it easier for coating with Tungsten or any other suitable material that will help contain any byproducts, prevent reactions with the working fluid, and potentially provide structural support to the thin plate fuel.

Propulsion is achieved without expelling matter by a non-inertial subsystem to generate substantial internal Coriolis recoil forces that supply propulsion. A subsystem discretely injects mass (fluids) radially into a non-inertial system having spinning radially-oriented fins mounted on a thin disc. The mass (fluid) is input at the circumference of the spinning system by radially injecting the fluid at high velocity onto one fin at a time at the outer end thereof. The mass centrifugally slows as it travels toward the axis and leaves the system at a very low velocity near the axis of rotation. The resultant integrated non-linear Coriolis reaction or recoil is constrained to acting through the axis of rotation of the spinning vanes by keeping the rotation rate constant. The net integrated reactive force acting on the axis of rotation of the subsystem produces a propulsive force. The injected and retarded fluids are captured near the rotation axis and recirculated to the input injectors. By conserving the reaction mass, the closed propulsion system depends only on the availability of power from a source.