Abstract: An improved rocket engine combustion chamber including a first chamber having a first diameter and located intermediate to a propellant injector and a second chamber having a second diameter that is larger than the first diameter. The combustion chamber extends radially outward from the first diameter to the second diameter suddenly at the intersection between the first and second chambers. Film cooling is provided by providing a stratified layer of low temperature fluid adjacent to the inner wall of the first chamber and surrounding a primary inner core of high temperature gases. The sudden stepped expansion at the interface between the first and second chambers provides secondary recirculation mixing of the propellants and facilitates complete combustion. In an additional aspect, the inner surface of the first chamber may be made of a material that has a high degree of thermal conductivity to minimize temperature gradients.

Abstract: Augmentation of the thrust achieved by a supersonic nozzle of continuous curvature is achieved by causing secondary combustion to occur in an annular region of the interior of the divergent section of the nozzle. The secondary combustion forms a secondary combustion gas that complements the primary combustion gas passing through the nozzle and maintains a wall pressure that is equal to or greater than ambient pressure at low altitudes, eliminating the negative component of the thrust in an overexpanded nozzle at takeoff.

Abstract: A solid rocket motor used as a booster rocket for a launch vehicle is provided with a mounting structure that permits attachment of the rocket motor to the vehicle in a manner that accommodates the expansion that the rocket undergoes during firing without risking disengagement of the rocket due to the shear forces caused by the expansion. The mounting structure includes a raised hub to which the thrust pin is attached, a series of aft-directed struts and a pair of transverse struts, all terminating in separate plates for bolting to the rocket motor case.

Abstract: A method and apparatus for using a magnetic field generated by a thruster magnet to control electron current emitted by a cathode assembly. The magnetic field reduces leakage current drawn by an inactive anode by producing a magnetic field in proximity to the inactive anode. This magnetic field increases the impedance to the anode for electron current which is produced in the cathode assembly. This reduction in leakage current reduces the amount of electron current produced by the cathode assembly. This control system can be implemented by connecting all thruster anodes and cathodes in parallel to an anode power supply.

Abstract: A solid rocket motor used as a booster rocket for a launch vehicle is provided with a mounting structure that permits attachment of the rocket motor to the vehicle in a manner that accommodates the expansion that the rocket undergoes during firing without risking disengagement of the rocket due to the shear forces caused by the expansion. The mounting structure includes a raised hub to which the thrust pin is attached, a series of aft-directed struts and a pair of transverse struts, all terminating in separate plates for bolting to the rocket motor case.

Abstract: A series of long slats, preferably parallel and spaced apart uniformly, extend from a base plate to form a series of cavities between the slats for trapping high energy ions in the exit plume of an ion accelerator. The plume shield is designed to minimize escape of ions and sputtered atoms from the shield. The effectiveness of the shield in trapping and retarding ions and sputtered atoms can be accomplished by biasing the potential of the shield with respect to an adjacent structure and by inducing a magnetic field parallel to a target area of the shield, which can limit electron current to the target area.

Abstract: Augmentation of the thrust achieved by a supersonic nozzle of continuous curvature is achieved by causing secondary combustion to occur in an annular region of the interior of the divergent section of the nozzle. The secondary combustion forms a secondary combustion gas that complements the primary combustion gas passing through the nozzle and maintains a wall pressure that is equal to or greater than ambient pressure at low altitudes, eliminating the negative component of the thrust in an overexpanded nozzle at takeoff.

Abstract: This invention is directed to mono- and bis-substituted oxetane monomers having fluorinated alkoxymethylene side chains, hydroxy-terminated prepolymers derived from these mono- and bis-substituted oxetane monomers and tetrahydrofuran (THF), and polymers produced from these prepolymers, as well as the synthesis processes associated with each, and the use of the monomers, prepolymers and ultimate polymers, both directly and as components of numerous compositions.

Abstract: The present invention provides, inter alia, novel fluorinated polymers and prepolymers derived from mono-substituted oxetane monomers having fluorinated alkoxymethylene side chains and methods of making such polymers and prepolymers.

Abstract: The present invention provides, inter alia, novel fluorinated polyurethane elastomers (e.g., fluorinated thermoset polyurethane elastomers and fluorinated thermoplastic elastomers) prepared from polyether prepolymers formed from mono-substituted fluorinated oxetane monomers (FOX monomers). In addition, the present invention provides methods of making such fluorinated polyurethane elastomers.

Abstract: A flow-through thrust takeout apparatus comprises an injection manifold (coupler) mounted to an engine and having a manifold passage. A ball line is attached to the injection manifold, and has a ball line passage fluidicly coupled with the manifold passage. A ball clamp is movably connected with the exterior surface of the ball line. A tank interface is attached to the ball clamp. The tank interface and ball clamp form a socket around the ball line to be movable relative to the injection manifold and the ball line. The tank interface is attached to a fuel tank. The interface member has an interface passage fluidicly coupled with the ball line passage to permit fuel flow from the fuel tank to the engine. A valve is mounted between the engine and the interface passage, and is adjustable to control fluid flow between the tank and the engine. The apparatus transfers the engine thrust from the rocket engine to the fuel tank, and the flow-through passages permit fuel transfer from the fuel tank to the engine.

Abstract: The present invention provides, inter alia, novel fluorinated copolymers and coprepolymers derived from mono-substituted oxetane monomers having fluorinated alkoxymethylene side-chains (FOX monomers) and tetrahydrofuran (THF). In addition, the present invention provides methods of making such copolymers and coprepolymers.

Abstract: Resins and carbon--carbon composites are formed from di(alken-1-yl) borinic acids and borinates, either as monomers or as nonpolymerizing additives in a monomer mixture, with the effect of sharply increasing the oxidative stability of the cured product. The compounds have the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are H, C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.2 -C.sub.6 alkynyl, C.sub.3 -C.sub.7 cycloalkyl, C.sub.5 -C.sub.7 cycloalkenyl, aryl, (C.sub.1 -C.sub.6 alkyl)-substituted aryl, (C.sub.2 -C.sub.6 alkenyl)-substituted aryl, or (C.sub.2 -C.sub.6 alkynyl)-substituted aryl, at least one of R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 being other than H.

Abstract: The present invention relates to solvent-free processes for the preparation of mono-substituted fluorinated oxetane monomers. Once prepared, the mono-substituted fluorinated oxetane monomers can be used to prepare prepolymers and polymers having fluorinated alkoxymethylene side chains.

Abstract: 4-Sulfonamidophenyl hydrazines are prepared by reaction between the hydrazine, optionally substituted, and the corresponding 4-substituted benzenesulfonamides, where the 4-substitution is an appropriate leaving group, in the presence of water and the absence of dimethyl sulfoxide as a solvent. The result is a product of unusually high purity.

Abstract: A passive mine detection apparatus useful for searching out buried mines, exploits natural soil emissions at microwave frequencies and unique interference-induced spectral reflection signatures from planar surfaces of buried mines interacting with the soil emissions. The apparatus comprises a focussed beam antenna, low noise amplifiers for respective polarizations, baseband converter, spectrum analyzer, A to D converter, signature recognition processor, display and/or alarm. Hand-held and vehicle-mounted implementations are disclosed.

Abstract: A heat exchanger includes a block having a first group of passages arranged in a generally circular pattern, a second group of passages spaced radially outward from the first group of passages and multiple groups of channels extending generally normal to and fluidly coupling the first and second groups of passages for radial flow therebetween. Selected pairs of passages, each including one passage from each passage group, are adapted for coupling to a first circulation line. The other ones of the passages are adapted for coupling to a second circulation line so that fluid heat from one of the circulation lines can be transferred to fluid from the other one of the lines in the heat exchanger. With this dense flow configuration, a compact heat exchanger can be constructed which, for example, is especially advantageous when used in conjunction with nuclear thermal rocket engines where space is at a premium. The dense fluid flow pattern also reduces material requirements and, thus, advantageously reduces weight.

Abstract: The fabrication of an off axis three-mirror telescope on only two substrates allowing two of mirrors to be formed on a common substrate, such as by means of diamond turning. The common substrate configuration is made possible by utilizing a common vertex for both the primary and tertiary mirrors so that alignment subsequent to fabrication requires placement of only two elements. In addition, all three mirrors in this invention share a common optical axis enabling an extremely simple mounting and housing design. The present invention is applicable for use in electro-optical imaging sensors operating from visible wavelengths to long infrared wavelengths. A telescope is formed by the assembly of three off-axis mirrors, including a primary mirror, a secondary mirror and a tertiary mirror.

Abstract: Diazomethane is produced in a continuous process with little or no explosion hazard, by dissolving an N-methyl-N-nitroso amine in a mixture of a water-miscible organic solvent that dissolves the N-methyl-N-nitroso amine and a water-immiscible organic solvent that dissolves diazomethane, and combining a stream of this solution with a stream of an aqueous inorganic base, allowing the aqueous and organic phases to settle after a suitable residence time, and phase separating the phases, all on a continuous basis. When using N-methyl-N-nitrosourea as the amine, the diazomethane process is preceded by a continuous nitrosation process involving combining aqueous solutions of methyl urea and a nitrite salt with an organic solution of a mineral or organic acid, the solvent in the organic solution being a mixture of the two organic solvents referred to above, allowing the aqueous and organic phases to settle after a suitable residence time, and phase separating the phases, all on a continuous basis.

Abstract: Inorganic nitrate oxidizers are combined in novel eutectic compositions which place the oxidizers in liquid form at ambient temperatures. These liquid combinations are then used in the preparation of a wide variety of energetic formulations, notably solution and emulsion propellants.