Abstract: A spacecraft having a body, one or more appendages coupled thereto, and a controller that implements methods that rotate the one or more flexible appendages to point it (them) towards the Sun to reduce spacecraft attitude pointing disturbances and improves spacecraft attitude pointing. The steps of the one or more appendages are timed to deadbeat the disturbance imparted to the spacecraft body. Timing of the appendage steps may be such that the periodic disturbances are phased to substantially cancel each other, or phased to decrease the magnitude of the net disturbance. The present invention also cancels solar array slew disturbances. The present invention cancels predictable disturbance torques before they produce a pointing error, improving the spacecraft pointing performance.

Abstract: An automated spacecraft orbit compensation system and method that maintains a spacecraft in a desired orbit. The spacecraft orbit compensation system and method is automated to minimize human intervention. The system includes apparatus for determining orbital errors (ranging data) and apparatus for determining the duration and orbital location of thruster firings to correct the orbit. Each of the apparatus are located at a ground station. The system and method generates ranging data indicative of the range of the spacecraft. The ranging data are processed to estimate the orbit of the spacecraft. The estimated orbit is used to compute a thruster burn plan for the following N days. The thruster burn plan is uploaded to the spacecraft. The above steps are repeated at regular intervals.

Abstract: A holographic optical element transforms a spectral distribution of light to image points. The element comprises areas, each of which acts as a separate lens to image the light incident in its area to an image point. Each area contains the recorded hologram of a point source object. The image points can be made to lie in a line in the same focal plane so as to align with a linear array detector. A version of the element has been developed that has concentric equal areas to match the circular fringe pattern of a Fabry-Perot interferometer. The element has high transmission efficiency, and when coupled with high quantum efficiency solid state detectors, provides an efficient photon-collecting detection system. The element may be used as part of the detection system in a direct detection Doppler lidar system or multiple field of view lidar system.

Abstract: A battery cell sleeve assembly includes a continuous cylindrical thermal sleeve extending between proximal and distal ends and has a plurality of substantially unidirectional longitudinally extending elongated heat conduction fibers having a thermal conductivity no less than that of aluminum embedded in an adhesive matrix. The thermal sleeve is received on the outer peripheral surface of a cylindrical battery cell and in a contiguous relationship with the battery cell. A cylindrical base member having an annular flange is attached to the thermal sleeve such that the distal ends of the heat conduction fibers are contiguous with the annular flange. With this construction, the annular flange operates as a heat shunt for drawing heat away from the thermal sleeve by conduction between the heat conduction fibers and the annular flange. In one embodiment, the heat conduction fibers are graphite and the thermal sleeve is between about 0.010 and 0.

Abstract: A spacecraft having nested reflectors that are released and deployed during a single release event using one or more dual reflector holddowns. The nested reflectors are held in place prior to release by the holddowns and are released during the single release event. The nested reflectors are secured to the body of the spacecraft by hinges attached to respective reflector backup structures and are releasably secured to the body using the one or more dual reflector holddowns. The reflector backup structures are secured by reflector interface brackets of the respective holddowns. An exemplary holddown has a separable tubular housing that is longitudinally secured together between an end cap and a release device. A threaded shaft 28 extends through the tubular housing, the end cap and the release device. A retraction spring is disposed around the exterior of the housing. The reflector interface brackets are secured to the outer and inner housings that attach the plurality of reflectors to the holddown.

Abstract: An integral, lightweight combustion chamber/nozzle assembly for a rocket engine has a refractory metal shell defining a chamber of generally frusto-conical contour. The shell communicates at its smaller end with a rocket body, and terminates at its larger end in a generally contact contour, which is open at its terminus and which serves as a nozzle for the rocket engine. The entire inner surface of the refractory metal shell has a thermal and oxidation barrier layer applied thereto. An ablative silica phenolic insert is bonded to the exposed surface of the thermal and oxidation barrier layer. The ablative phenolic insert provides a chosen inner contour for the combustion chamber and has a taper toward the open terminus of the nozzle. A process for fabricating the integral, lightweight combustion chamber/nozzle assembly is simple and efficient, and results in economy in respect of both resources and time.

Abstract: A computer implemented method of processing two-dimensional physical signals includes five basic components and the associated presentation techniques of the results. The first component decomposes the two-dimensional signal into one-dimensional profiles. The second component is a computer implemented Empirical Mode Decomposition that extracts a collection of Intrinsic Mode Functions (IMF's) from each profile based on local extrema and/or curvature extrema. The decomposition is based on the direct extraction of the energy associated with various intrinsic time scales in the profiles. In the third component, the IMF's of each profile are then subjected to a Hilbert Transform. The fourth component collates the Hilbert transformed IMF's of the profiles to form a two-dimensional Hilbert Spectrum. A fifth component manipulates the IMF's by, for example, filtering the two-dimensional signal by reconstructing the two-dimensional signal from selected IMF(s).

Abstract: The present invention is a two-part wind advisory system comprising a ground station at an airfield and an airborne unit placed inside an aircraft. The ground station monitors wind conditions (wind speed, wind direction, and wind gust) at the airfield and transmits the wind conditions and an airfield ID to the airborne unit. The airborne unit identifies the airfield by comparing the received airfield ID with airfield IDs stored in a database. The airborne unit also calculates the headwind and crosswind for each runway in both directions at the airfield using the received wind conditions and runway information stored in the database. The airborne unit then determines a recommended runway for takeoff and landing operations of the aircraft based on the runway having the greatest headwind value and displays the airfield ID, wind conditions, and recommended runway to the pilot.

Abstract: An arcade-style racing game is described. The game preferably includes a gaming surface, an actuator, a first feedback device, a game piece, a steering mechanism, a second feedback device, and a processor. A racing track may be depicted on the gaming surface. An actuator is preferably adapted to rotate the surface about an axis on command. The game piece is preferably positioned substantially adjacent to the surface. The steering mechanism is preferably indirectly connected to the game piece, and it may be adapted to move or rotate the game piece over a predetermined range. With use of the steering mechanism, a game player may position the game piece near the center of the racing track as the surface rotates about the central axis. A player's performance may be determined fractionally by continually determining the rotational position of the track and the lateral position of the game piece.

Abstract: An assembly for moving a robotic device along selected axes includes a programmable logic controller (PLC) for controlling movement of the device along selected axes to effect movement of the device to a selected disposition. The PLC includes a plurality of single axis motion control modules, and a central processing unit (CPU) in communication with the motion control modules. A human-machine interface is provided for operator selection of configurations of device movements and is in communication with the CPU. A motor drive is in communication with each of the motion control modules and is operable to effect movement of the device along the selected axes to obtain movement of the device to the selected disposition.

Abstract: A method is disclosed for controlling the attitude of a satellite by controlling the speed of the gimbals of CMGs in a cluster of CMGs, the CMG having respective wheels mounted on gimbals that are mounted on a satellite platform to rotate about different orientation axes. From starting conditions and end conditions relating to attitude and angular speed and time, a cluster configuration is determined that is remote from any singular configuration such that exchanging angular momentum between the cluster of CMGs and the satellite during a given length of time will give rise to the desired attitude maneuver. The orientation of each gimbal is changed in simultaneous and independent manner into its reference orientation by using an angular position reference, applied in an open loop in the local servo-control of the angular positions of the gimbals.

Abstract: A temperature compensation element for a high-temperature strain gage and the method of fabricating the same. Preferably, the element is a “dummy” strain gage not mechanically attached to the substrate. The element is encapsulated in an insulative material and used to compensate an active high-temperature strain gage and wired in a half-bridge configuration. The temperature compensation element and high-temperature strain gage are fabricated using the method of the present invention. This method includes temporarily adhering the element to a heat sink, encapsulated in an insulative material and then removed from the heat sink. Next, the element is either stacked or placed near the active gage. Ideally, the element and the active gage have substantially similar heat transfer and electrical properties.

Abstract: Polyimides and the process for preparing polyimides having improved thermal-oxidative stability derived from the polymerization of effective amounts of one or more of the polyamines such as the aromatic diamines, one or more of the tetracarboxylic dianhydrides and a novel dicarboxylic endcap having a formula selected from the group consisting of: wherein R1 is either a radical where R is either hydrogen or an alkyl radical of 1 to 4 carbons, R2 is either OH, NH2, F, or Cl radical, R3 is either H, OH, NH2, F, Cl or an alkylene radical, R4 is either an alkyl, aryl, alkoxy, aryloxy, nitro, F, or Cl radical, and R5 is either H, alkyl, aryl, alkoxy, aryloxy, nitro, F, or Cl radical. The polyimides are useful particularly in the preparation of prepregs and PMR composites.

Abstract: The present invention provides a method for preventing the decrease of the efficiency of heat transfer, caused by frost formation, in a precooler of an air breathing engine. In the precooler, the heat exchanger tube is provided. Into the heat exchanger tube, liquid hydrogen serving as a coolant is supplied. The main air flow is sent to the precooler via the intake duct, and the main air flow which is cooled down there, is then sent to a compressor of the air breathing engine. Via the nozzle provided in the middle of the intake duct, ethanol is mixed into the main air flow. Ethanol is carried into the precooler, and condenses together with the water vapor on the surface of the heat exchanger tube. A frost layer thus formed has less cavities and low thermal resistance as compared to that formed when the water vapor condenses solely. Therefore, the decrease of the performance of the heat exchanger, which is caused by the frost formation, can be prevented.

Abstract: A communication system and antenna system for use on a satellite. The communication system includes a transmitter and/or a receiver that are respectively coupled to the antenna system. The antenna system includes a plurality of stepped slot waveguides that each have a plurality of slots disposed in a broadwall thereof that form an array of slots. Adjacent slots of each waveguide are offset from a centerline of the respective waveguide and are spaced at half guide wavelength intervals, and selected slots are thus located at a different axial positions relative to other slots in the array. A feed waveguide having in input/output port is provided that couples RF energy between the plurality of stepped slot waveguides and the communication system. The stepped waveguide slot array antenna system provides phase control of the beam pattern produced thereby.

Abstract: Method and apparatus are provided for determining pressure using a non-intrusive sensor that is easily attachable to the plumbing of a pressurized system. A bent mode implementation and a hoop mode implementation of the invention are disclosed. Each of these implementations is able to non-intrusively measure pressure while fluid is flowing. As well, each implementation may be used to measure mass flow rate simultaneously with pressure. An ultra low noise control system is provided for making pressure measurements during gas flow. The control system includes two tunable digital bandpass filters with center frequencies that are responsive to a clock frequency. The clock frequency is divided by a factor of N to produce a driving vibrational signal for resonating a metal sensor section.

Abstract: A delay circuit includes a first network having an input and an output node, a second network having an input and an output, the input of the second network being coupled to the output node of the first network. The first network and the second network are configured such that: a glitch at the input to the first network having a length of approximately one-half of a standard glitch time or less does not cause the voltage at the output of the second network to cross a threshold, a glitch at the input to the first network having a length of between approximately one-half and two standard glitch times causes the voltage at the output of the second network to cross the threshold for less than the length of the glitch, and a glitch at the input to the first network having a length of greater than approximately two standard glitch times causes the voltage at the output of the second network to cross the threshold for approximately the time of the glitch.

Abstract: A delay circuit includes a first network having an input and an output node, a second network having an input and an output, the input of the second network being coupled to the output node of the first network. The first network and the second network are configured such that: a glitch at the input to the first network having a length of approximately one-half of a standard glitch time or less does not cause the voltage at the output of the second network to cross a threshold, a glitch at the input to the first network having a length of between approximately one-half and two standard glitch times causes the voltage at the output of the second network to cross the threshold for less than the length of the glitch, and a glitch at the input to the first network having a length of greater than approximately two standard glitch times causes the voltage at the output of the second network to cross the threshold for approximately the time of the glitch.

Abstract: Redundancy ring communication apparatus having a plurality of communication channels, that comprises normally used and redundant amplifier channels that are interconnected using selectively controllable switches. Pairs of amplifier channels may be selectively coupled together using controllable switches and hybrid couplers.

Abstract: The invention provides conductive compositions of matter, as well as methods for the preparation of the conductive compositions of matter, solutions comprising the conductive compositions of matter, and methods of preparing fibers or fabrics having improved anti-static properties employing the conductive compositions of matter.