An integrated propulsion and warhead system for an artillery round includes a propulsion, such as a solid rocket motor and/or an air-breathing jet engine, and an annular explosive concentrically arranged around at least a portion of the propulsion system. The integrated propulsion and warhead system is included in a propulsion section of the artillery round so that space in an adjacent guidance section is increased and the space allocation for the propulsion system and annular explosive is optimized.

Passive reactivity control technologies that enable reactivity control of a nuclear thermal propulsion (NTP) system with little to no active mechanical movement of circumferential control drums. By minimizing or eliminating the need for mechanical movement of the circumferential control drums during an NTP burn, the reactivity control technologies simplify controlling an NTP reactor and increase the overall performance of the NTP system. The reactivity control technologies mitigate and counteract the effects of xenon, the dominant fission product contributing to reactivity transients. Examples of reactivity control technologies include, employing burnable neutron poisons, tuning hydrogen pressure, adjusting wait time between burn cycles or merging burn cycles, and enhancement of temperature feedback mechanisms. The reactivity control technologies are applicable to low-enriched uranium NTP systems, including graphite composite fueled and tungsten ceramic and metal matrix (CERMET), or any moderated NTP system, such as highly-enriched uranium graphite composite NTP systems.

A heat exchanger which may be used in an engine, such as a vehicle engine for an aircraft or orbital launch vehicle. is provided. The heat exchanger may be configured as generally drum-shaped with a multitude of spiral sections, each containing numerous small diameter tubes. The spiral sections may spiral inside one another. The heat exchanger may include a support structure with a plurality of mutually axially spaced hoop supports, and may incorporate an intermediate header. The heat exchanger may incorporate recycling of methanol or other antifreeze used to prevent blocking of the heat exchanger due to frost or ice formation.

A rocket engine pintle injector with optimized spray pattern and with integrated igniter design for providing construction simplicity, throttleable thrust, stop/start/restart capability, optimized operational combustion, and improved ignition combustion stability. A user can start, throttle, and stop the engine by moving the internal concentric injector sleeve forward and backward to cause the fuel/oxidizer to spray out of the pintle head at different flow rates. The concentric igniter can be deployed so that the hot gasses or spark produced are radially projected into the spray of fuel/oxidizer surrounding the igniter. Once the fuel/oxidizer spray has been ignited, the igniter is stopped and retracted to protect the device from the heat of the combustion chamber and is ready for redeployment and restart of the engine as needed. Thus, a versatile, fully integrated, and scalable device can be used to start, throttle, stop, and restart any size rocket engine during any mission phase from launch to return from space.

A low-cost rocket includes an atmospheric flight part and an exo-atmospheric flight part, and uses the atmospheric air part to ascend into the atmosphere through the use of propellers for the atmospheric portion of the flight. The atmospheric flight part separates from the exo-atmospheric flight part in the vicinity of the exo-atmosphere and the exo-atmospheric rocket is launched thereupon. The atmospheric flight part descends through the atmosphere using autorotation of the propellers and, if necessary, a soft landing can be affected by controlling the pitch of the propellers just prior to landing.

A low-cost rocket includes an atmospheric flight part and an exo-atmospheric flight part, and uses the atmospheric air part to ascend into the atmosphere through the use of propellers for the atmospheric portion of the flight. The atmospheric flight part separates from the exo-atmospheric flight part in the vicinity of the exo-atmosphere and the exo-atmospheric rocket is launched thereupon. The atmospheric flight part descends through the atmosphere using autorotation of the propellers and, if necessary, a soft landing can be affected by controlling the pitch of the propellers just prior to landing.

A cardan joint spider comprising a body having four right-angled brackets, each bracket presenting two mutually perpendicular arms, the arm of one bracket being assembled to the arm of an adjacent bracket so as to form a cross-shaped spider having four branches.

A heat exchanger which may be used in an engine, such as a vehicle engine for an aircraft or orbital launch vehicle. is provided. The heat exchanger may be configured as generally drum-shaped with a multitude of spiral sections, each containing numerous small diameter tubes. The spiral sections may spiral inside one another. The heat exchanger may include a support structure with a plurality of mutually axially spaced hoop supports, and may incorporate an intermediate header. The heat exchanger may incorporate recycling of methanol or other antifreeze used to prevent blocking of the heat exchanger due to frost or ice formation.

The engine includes a chamber having an intake and an output for a fluid; a first enclosure configured to contain a source material; a system for at least partially ionizing the source material; and an ion accelerator configured to accelerate the ionized source material towards the chamber so as to cause the fusion of atomic nuclei of the ionized source material with atomic nuclei of the fluid.

An integrated propulsion and warhead system for an artillery round includes a propulsion, such as a solid rocket motor and/or an air-breathing jet engine, and an annular explosive concentrically arranged around at least a portion of the propulsion system. The integrated propulsion and warhead system is included in a propulsion section of the artillery round so that space in an adjacent guidance section is increased and the space allocation for the propulsion system and annular explosive is optimized.