Abstract: A rocket injector is provided with multiple sets of manifolds for supplying propellants to injector elements. Sensors transmit the temperatures of the propellants to a suitable controller which is operably connected to valves between these manifolds and propellant storage tanks. When cryogenic propellant temperatures are sensed only a portion of the valves are opened to furnish propellants to some of the manifolds. When lower temperatures are sensed additional valves are opened to furnish propellants to more of the manifolds.

Abstract: A ceramic superconductivity part, such as a wire 10, is produced through the partial oxidation of a specially formulated copper alloy in a core 12. The alloys contain low level quantities of rare earth and alkaline earth dopant elements. Upon oxidation at high temperature, superconducting oxide phases are formed as a thin film 14.

Abstract: Model-based and performance-based control techniques are combined for an electrical robotic control system. Thus, two distinct and separate design philosophies have been merged into a single control system having a control law formulation including two distinct and separate components, each of which yields a respective signal component that is combined into a total command signal for the system. Those two separate system components include a feedforward controller and a feedback controller. The feedforward controller is model-based and contains any known part of the manipulator dynamics that can be used for on-line control to produce a nominal feedforward component of the system's control signal. The feedback controller is performance-based and consists of a simple adaptive PID controller which generates an adaptive control signal to complement the nominal feedforward signal.

Abstract: A memory system is provided, of the type which includes an error-correcting circuit that detects and corrects errors, which more efficiently utilizes the capacity of a memory formed of groups of binary cells whose states can be inadvertently switched by ionizing radiation. Each memory cell has an asymmetric geometry, so that ionizing radiation causes a significantly greater probability of errors in one state than in the opposite state (e.g., an erroneous switch from "1" to "0" is far more likely than a switch from "0" to "1"). An asymmetric error-correcting coding circuit can be used with the asymmetric memory cells, which requires fewer bits than an efficient symmetric error-correcting code.

Abstract: A control system for a multi-motor system such as a space telerobot having a remote computational node and a local computational node inter-connected with one another by a high speed data link is described. A Universal Computer Control System (UCCS) for the telerobot motors is located at each node. Each node is provided with a multibus computer system which is characterized by a plurality of processors with all processors being connected to a common bus leading to a command processor. The command processor controls joint hardware and/or software for a plurality of direct current torque motors of the type used in telerobot joints and telerobot hand-held controllers. The motors are connected to the joint processor cards and respond to digital control signals from the joint command processor and a joint motor control card.

Abstract: A system of matching optics for gaussian beams. The matching optics system is positioned between a light beam emitter (such as a laser) and the input optics of a second optics system whereby the output from the light beam emitter is converted into an optimum input for the succeeding parts of the second optical system. The matching optics arrangement includes the combination of a light beam emitter, such as a laser with a movable afocal lens pair (telescope) and a single movable lens placed in the laser's output beam. The single movable lens serves as an input to the telescope. If desired, a second lens, which may be fixed, is positioned in the beam before the adjustable lens to serve as an input processor to the movable lens. The system provides the ability to choose waist diameter and position independently and achieve the desired values with two simple adjustments not requiring iteration.

Abstract: Composite flexible multilayer insulation systems (MLI) were evaluated for thermal performance and compared with currently used fibrous silica (baseline) insulation system. The systems described are multilayer insulations consisting of alternating layers of metal foil and scrim ceramic cloth or vacuum metallized polymeric films quilted together using ceramic thread. A silicon carbide thread for use in the quilting and the method of making it are also described. These systems are useful to provide lightweight thermal insulation for a variety of uses, particularly on the surface of aerospace vehicles subject to very high temperatures during flight.

Abstract: A master six-degree-freedom Force Reflecting Hand Controller ("FRHC") is available at a master site where a received image displays, in essentially real-time, a remote robotic manipulator which is being controlled in the corresponding six-degree-freedom by command signals which are transmitted to the remote site in accordance with the movement of the FRHC at the master site. Software is user-initiated at the master site in order to establish the basic system conditions and then a physical movement of the FRHC in Cartesean space is reflected at the master site by six absolute numbers that are sensed, translated, and computed as a difference signal relative to the earlier position. The change in position is then transmitted in that differential signal form over a high speed synchronized bilateral communication channel which simultaneously returns robot-sensed response information to the master site as forces applied to the FRHC so that the FRHC reflects the "feel" of what is taking place at the remote site.

Abstract: A composition containing 30 to 70% chromium carbide, 5 to 20% soft noble metal, 5 to 20% metal fluorides, and 20 to 60% metal binder is used in a powdered metallurgy process for the production of self-lubricating components, such as bearings. The use of the material allows the self-lubricating bearing to maintain its low friction properties over an extended range of operating temperatures.

Abstract: A quick release toggle clamp utilizes a spring that requires a deliberate positive action for disengagement. The clamp has a sliding bolt that provides a latching mechanism. The bolt is moved by a handle that tends to remain in an engaged position while under tension.

Abstract: A flexible heat transfer apparatus used to flexibly connect and thermally couple a thermoelectric cooler to an object to be cooled. The flexible heat transfer apparatus consists of a pair of flexible corrugated sheets made from high thermal conductivity materials such as copper, aluminum, gold, or silver. The ridges of the corrugated sheets are oriented perpendicular to one another and bonded sandwich-fashion between three plates to define an upper section and a lower section. The upper section provides X flexure, the lower section provides Y flexure, and both sections together provide Z flexure.

Abstract: In a distributed heterogeneous computer system having a plurality of computer nodes each operatively connected through a network interface to a network to provide for communications and transfers of data between the nodes and wherein the nodes each have a queue for containing jobs to be performed, an improvement for dynamically reallocating the system's resources for optimized job performance. There is first logic at each node for dynamically and periodically calculating and saving a workload value as a function of the number of jobs on the node's queue. Second logic is provided at each node for transfering the node's workload value to other nodes on the network at the request of the other nodes. Finally, there is third logic at each node operable at the completion of each job.

Abstract: A precision analog electronic circuit that is capable of sending accurate signals to an external device that has hostile electric characteristics, including the presence of very large common mode voltages. The circuit is also capable of surviving applications of normal mode overvoltages of up to 120 VAC/VDC for unlimited periods of time without damage or degradation. First, the circuit isolates the DC signal output from the computer. Means are then provided for amplifying the isolated DC signal. Further means are provided for stabilizing and protecting the isolating and amplifying means, and the isolated and amplified DC signal which is output to the external device, against overvoltages and overcurrents.

Abstract: A reference frequency distribution system for transmitting a reference frequency from a reference unit to a remote unit while keeping the reference frequency at the reference unit and remote unit in phase. A fiber optic cable connects the reference unit to the remote unit. A frequency source at the reference unit produces a reference frequency having an adjustable phase. A fiber optic transmitter at the reference unit modulates a light beam with the reference frequency and transmits the light beam into the fiber optic cable. A 50/50 reflector at the remote unit reflects a first portion of the light beam from the reference unit back into the fiber optic cable to the reference unit. A first fiber optic receiver disposed at the remote unit receives a second portion of the light beam and demodulates the reference frequency therefrom to be used at the remote unit.

Abstract: An improved fluid actuating system for imparting motion to a body such as a spacecraft is disclosed. The fluid actuating system consists of a fluid mass that may be controllably accelerated through at least one fluid path whereby an opposite acceleration is experienced by the spacecraft. For full control of the spacecraft's orientation, the system would include a plurality of fluid paths. The fluid paths may be circular or irregular, and the fluid paths may located on the interior or exterior of the spacecraft.

Abstract: High-gain MOCVD-grown (metal-organic chemical vapor deposition) AlGaAs/GaAs/AlGaAs n-p-n double heterojunction bipolar transistors (DHBTs) (14) and Darlington phototransistor pairs (14, 16) are provided for use in optical neural networks and other optoelectronic integrated circuit applications. The reduced base (22) doping level used herein results in effective blockage of Zn out-diffusion, enabling a current gain of 500, higher than most previously reported values for Zn-diffused-base DHBTs. Darlington phototransistor pairs of this material can achieve a current gain of over 6,000, which satisfies the gain requirement for optical neural network designs, which advantageously may employ novel neurons (10) comprising the Darlington phototransistor pair in series with a light source (12).

Abstract: A demodulator for OQPSK signals modulated with two unique words resolves eight possible cominbations of phase ambiguity which may product data error by first processing received I.sub.R and Q.sub.R data in an integrated carrier loop/symbol synchronizer using a digital Costas loop with matched filters for correcting four of eight possible phase lock errors, and then the remaining four using a phase ambiguity resolver which detects the unique words to not only reverse the received I.sub.R and Q.sub.R data channels, but to also invert (complement) the I.sub.R and/or Q.sub.R data, or to at least complement the I.sub.R and Q.sub.R data for systems using nontransparent codes that do not have rotation direction ambiguity.

Abstract: Apparatus for reducing acoustic transmission from mechanical or acoustic sources by means of a double wall partition, within which an acoustic pressure field is generated by at least one secondary acoustic source. The secondary acoustic source is advantageously placed within the partition, around its edges, or it may be an integral part of a wall of the partition.

Abstract: This airborne rescue system includes a boom (25) with telescoping members (31) for extending a line (19) and collar (14) to a rescue victim (16). The boom extends beyond the tip of the helicopter rotor (18) so that the victim may avoid in the rotor downwash. The rescue line is payed out and reeled in by winch (23). The line is temporarily retained under boom (25). When the boom is extended, the rescue line passes through clips (28). When the victim dons the collar and the tension in the line reaches a predetermined level, the clips open and release the line from the boom. Then the rescue line can form a straight line between the victim and the winch, and the victim can be lifted to the helicopter. A translator (57) is utilized to push out or pull in the telescoping members. The translator comprises a tape (58) and a rope (59). Inside the telescoping members the tape is curled around the rope and the tape has a tube-like configuration. The tape and rope are provided from supply spools 81 and 82, respectively.

Abstract: A thin, lightweight solar cell utilizes front contact metallization. Both the front light receiving surface of the solar cell and the facing surface of the cover glass are recessed to accommodate this metallization. This enables the two surfaces to meet flush for an optimum seal.