Abstract: A method is disclosed wherein a flexible space craft may be slewed by the application of positive and negative acceleration forces applied about a slewing axis. The method is such that at the end of the application of the slewing forces there is no residual energy in the excited modes. By examination of the response of an undamped and then damped structural mode to a sequence of step forces--entirely within the premises of structural dynamics discipline--a minimum-time zero-residual-energy torque profile with unequal intervening pulses is arrived at heuristically. Rigorous yet simple relationships are then established among the maneuver angle of a rest-to-rest slew, slew time, widths of the intervening pulses, and natural frequency and damping of a critical mode whose energy at the end of slew must be zero.

Abstract: The disclosed system comprises a receiver that is inductively coupled to one or more passive transmitters by means of a receiving inductor. The receiver comprises a sweep signal source which is coupled equally to the receiving inductor and a reference inductor. The receiving inductor is coupled to a passive transmitter which includes an L-R-C circuit comprised of a transmitting inductor, a temperature-dependent capacitor, and a resistor that may be variable or fixed, depending upon the application. As the sweep signal source passes through the resonant frequency of the passive transmitter, the passive transmitter forms a low impedance load magnetically coupled to the receiving inductor by means of the near or induction electromagnetic field produced by the inductor. Changes in the resonant frequency are used to determine temperature variation.

Abstract: A large antenna array is constructed in sub-arrays which are supported in a stacked and folded (stowed) condition, and then deployed by first unfolding and then expanding the stack. The sub-arrays are compressed together to yield a very compact stowed configuration, due to the absence of a continuous ground planes. The compressed sub-arrays are contained within a foldable cage like frame.

Abstract: A distributed feedback (DFB) laser for use in a bipolar field effect transistor laser (known as a BICFET laser) produces a single mode, stable, tunable laser. The single mode, stable, tunable characteristics of the laser are achieved by modifying the structure and operation of a previously disclosed high speed integrated heterojunction field-effect transistor laser by the inclusion of a grating in the n+ active regions to create a periodic refractive index profile. Independent operation of two n+ quantum wells provides frequency tuning through simultaneous and independent control of the mode spacing or mode frequency and the distributed feedback frequency.

Abstract: A Universal Memory Loader Verifier (UMLV) is disclosed. The loader comprises a system used to load and verify Operational Flight Programs (OFP) into an unlimited number of different types of avionics computers without the need for adding additional hardware (with the exception of an additional cable that may be unique to each particular computer being loaded and verified). The disclosed Universal Memory Loader Verifier (UMLV) consists of a portable, off the shelf, militarized, arm held, battery backed Personal Computer. The PC contains a custom interface card for different types of applications. The PC output is connected to a buffer box having a custom card therein by means of a cable. The buffer box is connected to a single ended driver/receiver type avionics computer through a unique cable. This connection requires an additional cable for each computer type. For all other applications, the PC is connected directly to the avionics computer by means of a unique cable.

Abstract: A fuel cell stack is cooled by evaporation of water into a carrier gas such as fuel or oxidant. The coolant and the carrier gas are separately supplied to the cooler, and this allows the fuel cell to operate at high pressure without raising cell temperature.

Abstract: A system for decoding an IF signal modulated with 4-ary words generated at a known spreading rate (PN code) comprises a receiver in which four known 4-ary words are generated at the same rate. The system then compares the incoming signals modulated with unknown 4-ary words with each of four known 4-ary words. Only one of the known words will be in phase with a received unknown word. The disclosure describes a system which determines which of the four words is in phase, this being the determinant of the identity of the unknown word.

Abstract: A method of separating structure comprising first and second components having different coefficients of thermal expansion and bonded together with a bonding material. Separation is achieved by immersing the structure in a cryogenic cooling substance to break the bonding material as a result of the different rates of expansion of the two components and then applying a force to separate the two components. Separation of a rotor and its windings is disclosed.

Abstract: A conformal telemetry package comprises a complete system including sensors, data acquisition components, a controller, RF transmitter, antenna and battery. The package is approximate 0.1 inch thick and is flexible and capable of conformable mounting to a curved surface. This package includes a printed circuit antenna such as a microstrip patch antenna. The bottom of the package is coated with an adhesive permitting the system to be mounted on surfaces such as the leading edge of an air foil. The package is kept thin and flexible by using multiple layers of flexible dielectric such as Teflon and extremely high levels of circuit integration.

Abstract: A system for correcting the distortion of the plane waves passing through the radome covering an antenna on a missile airframe by nutating the airframe, in both pitch and yaw to quantify the error in accordance with the nutation, and then determining the radome boresight error, and then correcting it in accordance with the solution of certain algorithms.

Abstract: This disclosure describes an optical system which serves to multiply the change in the path length of an optical system. The system employs an even number of pairs of mirrors which are displaceable along a line or lines parallel to an axis. Each segment of the optical path is between mirrors which are oppositely displaceable, so that the length of each segment is increased by an amount equal to twice the displacement of the mirror pairs.

Abstract: The disclosed system comprises a testing system which measures the stability of a moving target indicator radar transmitter. It automatically measures the imperfections of its internal in-phase (I)/quadrature (Q) demodulator, and it consists of a control computer, a synchronizer, a frequency synthesizer, an IQ demodulator, a low noise amplifier and a waveform recorder. A unit under test is inserted across the test set for measurement and calibration. The system set has the following features: (a) An automatic calibration routine that requires a tunable RF source. This source provides the RF drive to the UUT. (b) A discontinuous analog to digital (A/D) sample clock that has a precise controllable relationship with the RF pulse. The A/D sample clock samples only during the presence of the RF. (c) A method for computing stability using a table of amplitude and phase weighting coefficients and pulse positions. This table is generated by the user and any desired combination of values is possible.

Abstract: A damper system is disclosed in which is provided a segmented damper for damping the vibrations of a rotating shaft, the damper comprising a sealed porous fixed normally concentric cylinder surrounding the shaft, the space between the porous cylinder and the shaft being axially segmented by radial walls extending parallel to the axis of the shaft, the segmented space being filled with a fluid which is driven through the pores of said cylinder when said shaft vibrates to provide linear dampling.

Abstract: A personnel capsule extraction apparatus having a personnel capsule mounted on extraction platform which is ejected from a low flying aircraft at an altitude between five and ten feet above the ground. A drougue parachute is utilized to deploy a large extraction parachute which pulls the personnel capsule out of the aircraft.

Abstract: The high sublimation energy of industrial diamond pigment is combined with the clean ablation properties of an epoxy or urethane binder. The result is a low impulse decoy coating that has the desired compatibility with the decoy heat shield materials, good radar transmission, and a neutral effect on the electron densities in the wake. A high volume fraction of the diamond pigment is required to substantially reduce the blow-off impulse. The coating for a carbon-carbon substrate is a mixture of diamond pigment and a urethane or epoxy binder. Good quality, strong adherent coatings for a low-impulse decoy were fabricated in the range of 85 to 90 weight percent of diamond for both urethane and epoxy.

Abstract: A system is provided for determining the center of gravity of a body by providing a balance arm supported from a single pivot point, then positioning the body on the balance arm and measuring the rotation of the balance arm in two orthogonal planes. A disturbance weight is then added to the system at a known position, and the angle of rotation in the two planes is again measured. Using the known weights of the body and the disturbance weight, and the known distance of the disturbance weight from the pivot, and the measured angles, the precise location of the center of gravity of the body is determined by basic statics and standard trigonometry.

Abstract: A method is disclosed for making free standing multilayer films by depositing the films on a soluble substrate. The substrate solvent combination is chosen so that the solvent will not effect the multilayer materials. After deposition on the substrate, the multilayer films are cemented to a flat and smooth frame, in which a hole or window of the desired size and shape has been previously drilled. The adhesive, the films and the frame are insoluble in the chosen solvent for the substrate. After the adhesive is set, the substrate is dissolved leaving the multilayer film free standing within the frame. Also disclosed is a method for providing the films with a curvature.

Abstract: A high intensity heat exchanger that uses a solid copper heat sink having a lurality of integral pins formed on one side thereof, and an electrical insulator comprised of thin film of aluminum nitride (AlN) or diamond-like carbon (C) deposited on the other side. A device to be cooled, such as a computer chip, or an infrared detector cell is secured to the insulating layer by means of a very thin film of solder. A cooling liquid is circulated to the pins through conduits which also support the heat sink. The pins have a rectangular cross section and the spacing of the pins, and the fluid velocity are optimized to provide turbulent flow around the pins. The apparatus is provided with a space under the pins for a removable orifice plate, thereby enabling the optimization of the size, shape and number of orifices for a particular application.

Abstract: This disclosure describes an arrangement for cooling the exhaust nozzle of a gas turbine engine by selectively diverting the unheated total engine air flow directly to the exhaust nozzle of the engine. After the total air flow impinges on the back surface of the exhaust nozzle to rapidly cool the nozzle, the air is redirected back to the fan and the core engine for supporting combustion and to provide cooling in a generally conventional manner.

Abstract: A miniature solid state laser is optically pumped by ultraviolet radiation produced by a surface or corona discharge. The device is monolithic in that both the optical pump and the active medium are contiguous to a base material which is optically transparent in the ultraviolet range. The disclosed device consists of a substrate, a thin metal halide or crystalline or amorphous film deposited on the bottom of the substrate and a pair of spaced electrodes on the top of the substrate. When a high voltage pulse is applied across the spaced electrodes, discharge occurs between the electrodes and produces strong ultraviolet emissions which propagate through the substrate and dissociates the metal halide molecules in the film. This causes laser emission to occur on an atomic transition of the metal atom. The active laser medium may also be a crystalline platelet or amorphous thin film containing an impurity atom or molecule (an example would be YAG doped with Nd or LiYF.sub.4 (YLF) doped with cerium).