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 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 rocket engine system including a thrust chamber including walls that define an interior surface and a combustion section which is fluidically coupled to an output section. A coolant source containing a coolant. A means of heating the coolant. At least one port configured to apply the coolant to the interior surface to achieve a film cooling of the interior surface and wherein the coolant source is fluidically coupled to the means of heating and the at least one port.

A rocket engine system including a thrust chamber including walls that define an interior surface and a combustion section which is fluidically coupled to an output section. A coolant source containing a coolant. A means of heating the coolant. At least one port configured to apply the coolant to the interior surface to achieve a film cooling of the interior surface and wherein the coolant source is fluidically coupled to the means of heating and the at least one port.

A networked electronic ordnance system is provided. The system includes a first plurality of pyrotechnic devices connected to a first network bus. The system further includes a first bus controller connected to the first network bus. The system further includes a second plurality of pyrotechnic devices connected to a second network bus. The system further includes a second bus controller connected to the second network bus. The system further includes a bus interface circuit connected to the first bus controller by a first electrical connection and connected to the second bus controller by a second electrical connection.

A guiding array (200; 600) for a flow duct system (100; 200; 300; 500) includes a series of internested annular guide vanes (202), leading edges (230) or other common parts of the guide vanes being arranged to be positioned different distances from an upstream port, which may be an imaginary cylindrical surface substantially at a heat exchanger outlet (308; 508) within a fluid handling system such as an engine module (38).

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 system for electromagnetically exciting certain molecules within a volume of gaseous working fluid or charge via transition frequency heating for propulsion, comprising an electrical energy source (EES), an electromagnetic wave generator (EWG), a reflection coefficient measurement device (RCMD), a controllable electrical matching network (EMN), a proportional integral derivative controller (PIDC), and a propulsor cavity (PC), wherein said PC further comprises a transmission line that comprises a waveguide and a radio frequency (RF) window, wherein said RF window provides optical access to a heating zone where the charge resides or passes through, wherein said heating zone resides in the flow path between a propulsion system's charge inlet and nozzle exhaust.

A system for electromagnetically exciting certain molecules within a volume of gaseous working fluid or charge via transition frequency heating for propulsion, comprising an electrical energy source (EES), an electromagnetic wave generator (EWG), a reflection coefficient measurement device (RCMD), a controllable electrical matching network (EMN), a proportional integral derivative controller (PIDC), and a propulsor cavity (PC), wherein said PC further comprises a transmission line that comprises a waveguide and a radio frequency (RF) window, wherein said RF window provides optical access to a heating zone where the charge resides or passes through, wherein said heating zone resides in the flow path between a propulsion system's charge inlet and nozzle exhaust.

A field of test methods, and more particularly to a method for testing a device, the method including one operating stage corresponding to a stable value of one operating setpoint for the device and/or for a test bench for testing the device. The operating stage is finalized before a maximum duration threshold if a criterion associated with a set of physical parameters picked up during the operating stage is satisfied and if a confidence level associated with the set of physical parameters reaches at least a predetermined threshold.