Abstract: A method for forming a structurally reinforced panel member, and the panel itself, is disclosed. The method requires disposing a first set of sheets of curable composite material atop a tool forming surface, wrapping a plurality of mandrels with a second set of sheets of curable composite material, arranging the wrapped mandrels in side by side relation atop the first set of sheets, curing the structural assembly, and then removing the mandrels from the cured structural assembly. In this way, the structural assembly includes interior channels obtained when the mandrels are removed from the cured structural panel member. The material portions defining the channels provide increased strength for the structural assembly.

Abstract: The amplitude or frequency of a sinusoidal signal represented as sample values S.sub.1, S.sub.2, S.sub.3, S.sub.4 is estimated by computing a triplet of differences x.sub.1, x.sub.2, x.sub.3, where x.sub.1 is a difference between S.sub.2 and S.sub.1, x.sub.2 is a difference between S.sub.3 and S.sub.2, and x.sub.3 is a difference between S.sub.4 and S.sub.3. An indication of the estimate of the amplitude or frequency is computed as a ratio of algebraic functions of the differences x.sub.1, x.sub.2, x.sub.3. The amplitude is computed as the square root of a first ratio of algebraic functions, and the frequency is computed as an arc-cosine function of a second ratio of algebraic functions. Preferably the ratio is evaluated by a division operation computed as a polynomial approximation, and the square root function and the arc-cosine function are also computed as a polynomial approximation. Preferably ratios computed from a plurality of triplets are averaged together to give more accurate estimates.

Abstract: A modem is tested using HP3065 with AT commands. The modem is tested as a whole, thereby assuring that the correct components are being used and that they will work with one another.

Abstract: A single-precision multiplier used in a recursive digital filter is rendered more precise, without resorting to extended-precision or floating-point arithmetic. A double-precision multiplier produces a group of most significant bits (MSBs) and a group of least significant bits (LSBs). The LSBs are processed, including delaying them by one or two clock cycles, and are then added back to the LSBs produced during the present clock cycle. The top few bits of this first sum are right shifted as far as possible and added to the MSBs, the resulting second sum being the output of the overall multiplier.

Abstract: To demodulate an analog signal having information modulated by a carrier, the analog signal is chopped by a chopper, the chopped signal is digitized by a sigma-delta analog-to-digital converter to produce a series of digital samples at a sampling frequency, the digital samples are filtered in a digital decimating filter to produce data words, and the data words are modulated by an intermediate frequency signal to produce a detected information signal. The various frequency signals are generated by a phase-lock loop so that the intermediate frequency is the difference between the carrier frequency and the chopping frequency, and both the chopping frequency and the intermediate frequency are sub-multiples of the sampling frequency.

Abstract: A process for manufacturing stiffened composite skin panel structures possessing novel hollow crown-shaped stiffener elements, and further including any combination of forward spars, aft spars, and transversely extending shear ties. The novel process embraces fabrication and curing of these structures without the use of mandrels. In practicing the method, the crown-shaped stiffeners, spars and shear ties are integrally bonded to a planar or curved skin structure to provide axial stiffness in semimonocoque components such as aircraft wings, stabilizers, fuselages, etc. The method of fabrication yields highly producible, structurally efficient composite aircraft components.

Abstract: A method of precision cutting fabric material while obtaining cleanly cut edges involves placing the material on a flat support surface, identifying one or more regions of material to be cut, placing adhesive tape on both sides of the material, and then using an appropriate tool to first squeeze the tape into the fabric at the cutting region, and effecting the cutting of the taped material. A reinforcing woven fabric constituent for incorporation into a metal matrix composite, produced by the method, is also disclosed.

Abstract: Apparatus and a method are disclosed for eliminating fiber distortions ("fiber swimming") and separations ("fiber fish eyes") via a premliminary step taken prior to consolidation of "green", fiber-reinforced metal matrix materials. The apparatus includes a first member for supporting the "green" metal matrix material pack, a second member to cover the "green" pack, the thermal coefficient of expansion of the first member being smaller than the thermal coefficient of expansion of the second member, the second member being secured to the first member atop the "green" pack to form a retort, and the entire retort being heated to an off-gassing temperature, where the second member bows outwardly away from the pack to relieve pressure from the pack.

Abstract: A method for thermomechanically processing gamma titanium aluminide alloy wrought products comprises the following steps: a) a near gamma titanium aluminide alloy ingot is cast; b) the ingot is hot isostatically pressed (HIP'ed) to seal off casting defects; c) the HIP'ed ingot is prepared into suitable forging preforms with or without intermediate homogenization heat treatment; d) the forging preforms are isothermally forged into suitable end product preforms at temperatures sufficiently close to the phase line between the alpha+gamma and alpha-two+gamma phase fields so as to break down the ingot microstructure and to yield a largely equiaxed gamma microstructure; and e) the end product preforms are processed into the desired wrought end products through a controlled rolling process or a closed-die forging operation.

Abstract: A structural armor assembly including a superplastically formed sandwich member having on one side one face sheet of high toughness, high-strength titanium alloy material, and on the other side a second face sheet made of non-superplastically formable metal matrix composite abrasive material. Abrasive materials in the form of "KEVLAR".RTM. or "SPECTRA".RTM. are provided inside cells in the sandwich member to serve as a "catcher's mitt" to absorb part or all of the energy of the ballistic fragments after they have been abraded by the material of the second face sheet.

Abstract: A method for making a cooling system for reducing the temperature of an exhaust-impinged structural panel includes an upper, primary cooling panel having boundary layer film-forming openings therein, a middle, secondary cooling panel having openings for directing a flow of cooling fluid into impingement with the primary cooling panel, and a lower cooling panel. The lower and upper panels together delimit a truss structure which structurally reinforces the cooling system, and the lower panel forms with the upper panel channels for conducting pressurized fluid first to the openings of the secondary cooling panel and then to the openings of the primary cooling panel.

Abstract: The robotic end-effector system comprises a mounting bracket assembly attached to a manipulator arm of a robot. A dual shaft motor is attached to the mounting bracket assembly. The motor has first and second rotatable output shafts. The first shaft is for mounting an encoder for providing position data. A mechanical drive mechanism is connected to the motor and to the mounting bracket assembly. The mechanical drive mechanism converts rotational motion of the second output shaft to translational motion. A passive compliance system is connected to the mechanical drive mechanism. A load sensor system is supported by the compliance system for providing force data. An end-effector end piece is connected to the load sensor system. A closed loop computer control system is in communication with the motor for processing the position data and the force data for providing micro positioning of the end-effector end piece and for providing an active system compliance, thereby achieving the desired end-effector function.

Abstract: A method and apparatus for forming cleanly defined holes through reinforced metal matrix material includes a drill bit with a shank portion and flutes on said shank portion, the drill bit capable of withstanding a chip load of at least about 0.008 inch/rev/flute, and preferably in the range of from about 0.008 inch/rev/flute to about 0.012 inch/rev/flute, achieved through turning the bit at a speed within the range of about 18 surface feet per minute ("sfpm") to about 20 sfpm, and advancing the bit at an aggressive rate through the metal matrix material at a rate of from about 3 inches per minute to about 6 inches per minute.

Abstract: A novel composition comprising a metal or ceramic matrix material includes a reinforcing system of hollow, similarly aligned carbon-coated ceramic fibers which provide high strength, increased creep resistance and a significant reduction in weight. Also disclosed is a novel structural component incorporating the reinforcing system of hollow fibers to provide a mechanism enabling fluids or gases to pass or be injected through the element fibers for cooling or other functions. A method for fabricating the hollow fiber-reinforced component is also disclosed. Various applications for the fiber-reinforced structural component are also disclosed.

Abstract: The apparatus for the automated fueling of a launch vehicle includes a mobile fuel line platform assembly for carrying a fuel line assembly. A gross mechanical actuation mechanism provides gross positioning of the platform assembly relative to a fuel tank inlet. A micro-positioning mechanism provides micro-positioning of the fuel line assembly relative to the fuel tank inlet. A floating plate assembly securely connects the fuel line assembly to the fuel tank inlet. Leak detector detects any leaks in the connection between the fuel line assembly and the fuel tank. The present invention augments existing space program hardware thereby removing human involvement and increasing vehicle/environment safety.

Abstract: A reusable flyback satellite system comprises a refly apparatus and accelerating and positioning apparatus. The refly apparatus provides acceleration and injection into orbit, on-orbit functions services for supporting a payload, de-orbiting, re-entering and landing on a runway. The accelerating and positioning apparatus is attached to a carrier aircraft, the accelerating and positioning apparatus releaseably supporting the refly apparatus. The carrier aircraft positions the accelerating and positioning apparatus at a desired first position wherein the accelerating and positioning apparatus is detached from the carrier aircraft. Thereafter, the accelerating and positioning apparatus positions the refly apparatus to a second position wherein the refly apparatus is detachable from the accelerating and positioning apparatus. The second position is such that the refly apparatus can achieve a desired orbit.

Abstract: A high rate, continuous production, slush hydrogen generator includes a tank, apparatus for creating a vacuum in the tank, apparatus for delivering triple point (T.P.) liquid hydrogen (LH2) to the tank, apparatus for interacting with the vacuum in the tank to produce slush hydrogen from the T.P. LH2, where the T.P. LH2 has a substantially constant solid fraction, and apparatus for delivering cold vapors from the slush in the tank to the vacuum creating apparatus. The apparatus for producing slush hydrogen in the generator includes a perforated spray ring for evaporating the T.P. LH2 and apparatus for delivering the LH2 under pressure to the spray ring.

Abstract: A stack of metallic sheets is constructed for selective diffusion bonding followed by superplastic forming to yield a metallic sandwich structure. The invention resides in the provision of gas distribution channels in the stack for assuring balanced and complete distribution of gas throughout the unbonded areas of the stack. The gas is used for expansion of the stack into a sandwich structure during the step of superplastic forming. The novel construction of each channel comprises superimposed grooves in opposed face sheets of the stack and slots in the core sheet(s) of the stack.

Abstract: The fluid management system comprises a mixing/recirculation system including an external recirculation pump for receiving fluid from a zero gravity storage system and returning an output flow of the fluid to the storage system. An internal axial spray injection system is provided for receiving a portion of the output flow from the recirculation pump. The spray injection system thermally de-stratifies liquid and gaseous cryogenic fluid stored in the storage system.

Abstract: This invention comprises the use of integral pulse frequency modulation (IPFM) reaction jet controllers for multi-axis precision tracking of moving objects with flexible spacecraft, and vibration suppression. Two sets of position, rate and accelertion command profiles for multi-axis tracking are disclosed: one for a payload initially facing the zenith and the commands based on a pitch-roll sequence; the other for a payload facing the nadir and the commands based on a roll-pitch sequence. The procedure for designing an IPFM controller for tracking a given, inertial acceleration command profile is disclosed. Important elastic modes of a spacecraft are identified according to their spontaneous attitude and rate response to the minimum impulse bit of the thrusters. The stability of the control-structure interaction is shown to be governed by the ratio of the moments of inertia of the flexible to the rigid portions of the spacecraft.