Abstract: An actuator for continuously aligning the primary mirror relative to the scraper the other resonator mirrors and the feedback mirror in a high power laser resonator, comprised of extended portions of the resonators primary mirror, feedback mirror and scraper mirror for a low power laser beam to travel parallel to but offset from the high power laser beam for aligning the mirrors. The low power laser beam is used to measure the position of the mirrors in the resonator. The low power beam is split into a beam which is incident on a quadrant cell for measuring the tip and tilt of the feedback mirror relative to the primary mirror and a beam which measures the translation of the feedback mirror relative to the primary mirror. A controller receives the data form the quadrant cells and sends signals to actuators on one mirror to move it relative to the other thus keeping the mirrors in constant alignment.

Abstract: A rocket engine shaft seal which prevents leakage from escaping from the pump to the turbine along the shaft 1. The seal has a bellows spring 8 for pushing the floating ring seal 2 into contact with the mating ring 4 when the rocket engine is off, thus sealing the liquid in the pump section more reliably. When the engine is on, the pressure of the fuel will overcome the force of the bellows spring 8, moving the floating ring seal 2 away from contact with the mating ring 4, so as to save wear on the face contact portion 5 of the floating ring seal and preserve a good seal when the engine is off. The floating ring seal 2 has an inner diameter 11 for forming a seal with the shaft 1. The shaft 1 may have a labyrinth on it for forming a labyrinth seal with the floating ring seal 2, or with the floating ring seal and the bellows adapter's arm portion 13 for forming a longer labyrinth seal.

Abstract: A method for the manufacture of articles such as heat exchangers, heat absorbers, thermal skins, rocket engine components and the like which method comprises providing a substrate or mold, etching or cutting cooling channels therein, filling said channels and processing to form a part which is then fabricated into the final article. In the production method a unique filler or core material comprising a strontium composition is utilized thus rendering a product of high quality and net-shape finish.

Abstract: The present invention is a method of earth orbit space transportation and return utilizing a reusable flyback satellite. A reusable flyback satellite is positioned to a desired release point which provides the capability of the satellite to achieve a desired orbit. The satellite is deployed from that release point. It is then injected into orbit. On-orbit function and services to a payload of the satellite are provided. The satellite is de-orbited, re-entered and landed with airplane-like functionality and utility.

Abstract: An orifice compensated hydrostatic bearings wherein a roughened surface area retards the hydrostatic fluid flow exiting the hydrostatic bearing reducing the whirl frequency ratio while increasing the bearing stiffness and life.

Abstract: The present invention provides novel joint designs and methods for holding together and drawing together interface edges of workpieces during friction stir welding. The method includes providing an interface edge (30A) on a first workpiece (20A), and an interface edge (30B) on a second workpiece (20B) that is complementary with the interface edge of the first workpiece. The interface edges cooperate with consumable pins (38) to hold the first and second workpieces together. In a preferred embodiment, the interface edges cooperate to draw the first and second workpieces together when a load in a direction normal to the interfaces is applied along the mated interfaces.

Abstract: Aqueous black liquor is gasified in a molten salt by spraying the black liquor into an enclosed zone above the surface of a turbulent molten salt pool. The black liquor is dried by means of hot gases rising from the surface of the pool and the resulting solid particles falling into the turbulent molten salt pool are dispersed and converted into a combustible gas and a reduced melt in which sulfide comprises at least about 95% of the total sulfur present. In a preferred embodiment the product gas is purified, burned and utilized in a gas turbine.

Abstract: The present invention provides a method to repair a void in an aluminum alloy, particularly a void resulting from an exit hole left from friction stir welding (FSW). The method includes machining the void to provide a tapered bore (34) through a parent metal, i.e., the aluminum alloy (30), providing grooves and ridges (36) on a sidewall of the tapered bore, inserting into the bore a consumable tapered plug (38) having an included angle less than, or equal to, that of the tapered bore, and rotating the plug inside the bore under an applied load to plasticize both its surface and the ridges on the parent metal tapered bore. The tapered plug is preferably attached at its proximal end to a nonconsumable heat sink (40) to remove excessive heat generated during rotation of the plug. Also, a support bracket is temporarily attached to the aluminum alloy adjacent the tapered bore to receive a distal end of the plug (38) and to react to the applied load.

Abstract: A method for monitoring a thin film of polyimide material on the surface of a liquid crystal display uses nonlinear second-order surface spectroscopy to monitor the condition of a surface. Electromagnetic radiation is directed towards the surface and the second harmonic or other second-order frequency responses are monitored to detect the state of the surface. Preferably, a laser, input optics and output optics are utilized to create the second-order frequency response that is detected.

Abstract: The present invention provides an in-process method to repair voids in an aluminum alloy, particularly a friction stir weld in an aluminum alloy. For repairing a circular void or an in-process exit hole in a weld, the method includes the steps of fabricating filler material of the same composition or compatible with the parent material into a plug form to be fitted into the void, positioning the plug in the void, and friction stir welding over and through the plug. For repairing a longitudinal void (30), the method includes machining the void area to provide a trough (34) that subsumes the void, fabricating filler metal into a strip form (36) to be fitted into the trough, positioning the strip in the trough, and rewelding the void area by traversing a friction stir welding tool longitudinally through the strip. The method is also applicable for repairing welds made by a fusing welding process or voids in aluminum alloy workpieces themselves.

Abstract: A coating for sealing carbon--carbon composites against hydrogen. The coating comprises a first layer of silicon carbide and a second layer of a glass, glass-ceramic or a low-melting-point metal such as tin or an alloy thereof. Particularly when such second layer is a glass, e.g. an SiO.sub.2 -containing glass, or a glass-ceramic, preferably the silicon carbide coating is pretreated, e.g. by oxidation thereof to form a thin layer of SiO.sub.2 prior to application of the glass layer. The glass layer can be an SiO.sub.2 glass formed by sputtering or by decomposition of tetraethylorthosilicate (TEOS) applied to the oxidized silicon carbide coating. An alkali metal oxide, e.g. Na.sub.2 O, or an alkaline earth metal oxide, e.g. BaO, can be added to the SiO.sub.2 glass.

Abstract: A nozzle for mixing of two reacting fluids wherein the first reactant, flowing across the nozzle, exhibits a variation in reactivity towards the second fluid, introduced through the nozzle and mixing and reacting with the first fluid within the nozzle, and wherein the nozzle is configured to permit this second fluid to be introduced in a way as to compensate for the variation in reactivity and to produce uniform reactant mixture from the two fluids.

Abstract: A fiber optical "T" coupler for sending and receiving signals on the same fiber optic element to facilitate ease of building and operating fiber optic communications networks. The fiber optical "T" coupler has three GRIN lenses, a receiving GRIN lens, a transmitting GRIN lens and a focusing GRIN lens, each having a focusing end and a collimating end. The transmitting GRIN lens' and the focusing GRIN lens' collimating ends are attached to and optically connected to the collimating end of the receiving GRIN lens. Fiber optic elements can be connected to the GRIN lenses focused ends for receiving signals to be collimated or for sending focused signals from the collimated end of the GRINs. Thus a light emitting transducer sends light to the transmitting GRIN lens and through the receiving GRIN lens to a fiber optic element. The same fiber optic element brings light to the receiving GRIN lens which is optically connected to the focusing GRIN lens which focuses the light on a light detecting transducer.

Abstract: A fiber optic coupler having a first lens element for inputting a point source of light from an optical cable and outputting a collimated light, optically coupled to one or more lens elements for receiving an input of collimated light from the first lens element and outputting a focused point of light into a fiber optic cable. The lens elements can be gradient index lens. The lens elements can be of varying sizes such that the first lens element can optically connect to one or more smaller lens elements to couple or split optical signals for two way communication on the optical cables.

Abstract: A foil bearing is used wherein the support for the foils are hydrostatically rather than mechanical spring supported. The bearing housing has a plurality of orifices for admitting hydrostatic fluid over the foils. The foils are then supported by the hydrostatic fluid. The hydrostatic foil bearing is stiffer, longer lasting, and easier to assemble than foil bearings with mechanical spring backings. Hydrostatically supported foil bearings also have variable spring rates depending on the pressure of the hydrostatic fluid, thus allowing the hydrostatic foil bearing to have adjustable capacity with speed. In addition the hydrostatic foil bearing damping between the rotor and housing is greater than foil bearings with mechanical spring backing.

Abstract: This invention relates to modulating light transmitted in an optic fiber. A passive light modulating device such as a polarizing material, a filter, or an attenuator is placed between two facing collimated ends of GRIN lenses attached to two optic fibers. The passive light modulating device modulates the light in the desired manner as it is transmitted between the two optic fibers. An active light modulating device such as a switch or an amplifier may also be used between the two GRIN lenses to actively modify the transmitted light.

Abstract: A Fourier transform interferometer for rapid scanning of scenes such as explosions wherein an incoming beam of light to be analyzed is split by a beam splitter into a first portion and a second portion. The first portion of the incoming light is sent down one arm of the interferometer where it passes through a rotating scanning cube for changing the path length in that arm of the interferometer. The light is then reflected by a retro mirror and sent back through the scanning cube to the beam splitter for sending a portion of the returning beam to a detector. The second portion of the incoming light is sent down a second arm of the interferometer where it passes through a compensator. The light is then reflected by a retro mirror and sent back through the compensator to the beam splitter for sending a portion of the returning beam to a detector. The first and second portions of the incoming light having differing path lengths interfere and the detector measures the fringes created.

Abstract: A concentrating solar array consisting of a roll of reflective film which is stretched between tension wires strung between a pair of wire stays. There is a roll of film and a take up roll such that the film can be unrolled from the storage roll and pulled toward the take-up roll to replace degraded film. A pair of extension arms holds a solar cell at a fixed position relative to the solar concentrator film surface to receive concentrated sunlight. The roll of reflective film ensures the life requirements of the solar concentrator can be met in space, by replacing exposed concentrator film as it degrades.

Abstract: This invention provides a molten salt, solar central smooth tube receiver that is able to effectively absorb a peak solar flux of 1.42 MW/M.sup.2 by constructing the receiver from low cycle fatigue 625 alloy. Although higher flux levels are attainable for a smooth tube receiver by reducing the tube diameter to increase the salt's heat transfer coefficient, the receiver's size is optimized at this flux level to minimize capital and performance costs. Analogously, material provides substantial performance and capital cost improvements for receivers constructed with internally enhanced film coefficient tubes. The receiver's cost is minimized by utilizing autogenously welded and drawn tubing with the weld located at the tube's neutral axis to provide minimal strain at the weld.

Abstract: Leakage of propellants such as oxygen and hydrogen in an enclosed environment in the atmosphere can lead to fires or explosions. For storage tanks on reusable launch vehicles such as the space shuttle where propellant is to be stored in the cargo bay of the vehicle, the storage tank should be filled while the vehicle is at a safe altitude to avoid the dangers associated with propellant leakage. The invention a process for filling propellant tanks at safe altitudes where if there is propellant leakage ignition will not occur. The process involves launching the vehicle with an inert gas in the storage tanks, dumping the inert gas and filling the tanks in the cargo bay from the main propellant tanks during the launch once the vehicle is at a safe altitude. The propellant can be dumped overboard and the storage tanks filled with an inert gas in case of a mission abort if the vehicle needs to make an emergency landing.