Abstract: A system including a passive heat sink is depicted. A passive heat sink may include an enclosure housing a nonmetal matrix composite. At least one surface of the enclosure may be in contact and/or close proximity to a heat source. The enclosure may be formed through an additive manufacturing process.

Abstract: A system including a flow-through heat sink is depicted. A flow-through heat sink may include an enclosure housing a nonmetal matrix composite. At least one surface of the enclosure may be in contact and/or close proximity to a heat source. The enclosure may be formed through an additive manufacturing process.

Abstract: Techniques for placing a satellite into a highly inclined elliptical operational orbit having an argument of perigee of 90° or 270° include executing an orbit transfer strategy that transfers the satellite from a launch vehicle deployment orbit to the operational orbit. The launch vehicle deployment orbit is selected to have an argument of perigee of approximately 90° greater than the argument of perigee of the operational orbit, an apogee altitude of approximately 14000 km and a perigee altitude of approximately 500 km. The orbit transfer strategy includes (i) an apsidal rotation of approximately 90°, at least a substantial part of the apsidal rotation being attained without expenditure of any satellite propellant; and (ii) an electric orbit raising maneuver to attain an apogee altitude and a perigee altitude required by the HIEO.

Abstract: An arrangement is disclosed for providing the functionality of a four port, four channel rotary switch. The arrangement includes a first four port rotary microwave switch, the first switch including a first rotor and a first set of four waveguide ports, and a second four port rotary microwave switch, communicatively coupled to the first switch, the second switch including a second rotor and a second set of four waveguide ports. Each of the first switch and the second switch has at most three channels.

Abstract: A spacecraft includes substantially parallel first radiator and second radiator panels, and a transverse panel coupled, having a width, W, coupled therebetween. The spacecraft also includes a first heat pipe having a first section parallel and proximate to the first radiator panel and a second section parallel and proximate to the transverse panel, a second heat pipe having a first section parallel and proximate to the second radiator panel and a second section parallel and proximate to the transverse panel and a third heat pipe, proximate and parallel to the transverse panel, the second section of the first heat pipe, and the second section of the second heat pipe. The third heat pipe has a length, L, substantially greater than W/2.

Abstract: A directionally-controlled roll-out elastically deployable solar array structure is disclosed. The structure includes one or more longitudinal elastic roll out booms that may be closed section or open section to allow for efficient rolled packaging onto a lateral mandrel. A flexible photovoltaic blanket is attached to a tip structure and to a lateral base support structure, but remains uncoupled from the longitudinal booms. The solar array system may be stowed simultaneously into a rolled package comprised of the roll out booms and the flexible planar blanket together, or onto independent rolls. Alternatively, the system may be stowed by rolling the booms, and accordion Z-folding the hinged flexible photovoltaic blanket into a flat stack. Structural deployment is motivated by the elastic strain energy of the roll out booms, and several methods of deployment direction control are provided to ensure a known, controlled, and unidirectional deployment path of the elastically unrolling booms.

Abstract: A system includes a first control system configured to operate at a first clock speed, a second control system configured to provide an output to the first control system and configured to operate at a second clock speed different from the first clock speed, and a synchronization module operatively connecting the first control module to the second control module and configured to synchronize the first control system and the second control system such that the output of the second control system is timed to synchronize with the first clock speed.

Abstract: A high capacity satellite having a launch configuration in which one or more antenna reflectors may be stored forward of a forward surface of the spacecraft and an on-orbit configuration in which a reflector boom may be rotated to displace the one or more antenna reflectors a substantial distance from the main body in the yaw axis direction and in a direction orthogonal to the yaw axis direction.

Abstract: As each tach pulse time duration is known a priori, it may be utilized by a system to an advantage. A counter may be started on the falling edge of a tach pulse. This counter may count to the rising edge of a second tach pulse, such as the next tech pulse. During the duration of the tach pulse the FPGA may calculate the RPM of a motor. In this way, during each commutation period, a RPM may be calculated. In contrast to legacy systems where a RPM calculation may have been performed every other tach pulse, the present system may perform a RPM calculation during each commutation period and/or tach pulse duration. Stated another way, the calculation of the delta of the commutation period less the tach pulse duration may be determined while the counter is idle.

Abstract: A launch vehicle payload that includes at least two spacecraft is disclosed. The launch vehicle includes a single payload adapter. Each spacecraft has a launch vehicle adapter structure providing a respectively coplanar structural interface directly with the single launch vehicle payload adapter. The spacecraft share a launch vehicle payload fairing volume substantially side-by-side and are detachably coupled together such that a positive clearance is provided between adjacent, non-abutting structural body surfaces of each spacecraft.

Abstract: The sublimation capability of a porous metal plate used in a sublimator is maintained by heating the porous metal plate at an elevated temperature in a flowing stream of oxygen for an extended period of time to form an oxidized surface. A short chain molecule, such as citric acid, is attached to the oxidized surface having multiple functional carboxylate groups and no hydrophobic tail.

Abstract: A DC/DC converter includes an internal transistor and a current sensor that is operable to sense a current passing through the transistor. The DC/DC converter also includes an output current estimator module that estimates the output current based on the sensed transistor current.

Abstract: A preload reducing fastener adapted to be fastened into a system in which includes a release system. The fastener may have an integral collar which is adapted to change shape, as in the case of a shape memory alloy. The application of heat to fastener may deform the collar such that the fastener may move axially in the load direction, thus reducing the preload previously held by the fastener. A preload reducing device including a preload reducing fastener may include an outer case adapted to center and capture a preload reducing fastener. The case may center the fastener in a desired location in a preloaded system, and may also capture the fastener after release of the system.

Abstract: An elastically deployable three-dimensional panel structure for a solar array that can be collapsed to a flattened state and subsequently rolled, bended, or folded to achieve a compact stowage volume. The panel structure has top facing planar surface region on which one or more photovoltaic modules are attached, and other non-planar regions, located at the structure edges, that increase the deployed stiffness and strength of the structure. The deployable structure may include one or more panel structure modules mechanically interconnected in series and one or more photovoltaic modules electrically interconnected and mechanically adhered to the panel structure surface or tensioned within an openings within in the panel structure. Structural deployment is motivated by the elastic strain energy of the one or more panel structures from their stowed state. Deployment control is provided to ensure a known and repeatable deployment path through interlocking strips attached to one or more panel structures.

Abstract: A dual check valve includes, a housing having a cavity fluidically connecting three ports, a movable member movably engaged within the cavity from at least a first position occluding a first port of the three ports, a second position occluding a second port of the three ports, and a third position allowing flow between both the first port, the second port and a third port of the three ports.

Abstract: A spacecraft has a high efficiency multi-beam antenna (MBA) system that serves a coverage region on the Earth. The coverage region subtends an angle, when viewed from the spacecraft, of at least ten degrees. The antenna system provides, within the coverage region, at least sixteen spot beams. A signal provided by the MBA system to each spot beam has a carrier to interference ratio (C/I) of no less than 20 dB. The system enables use of a three color frequency reuse scheme without recourse to signal encoding.

Abstract: A spacecraft propulsion system has at least one chemical thruster, at least one electric thruster, a propellant supply arrangement that stores a propellant and a propellant conditioning arrangement configured to convert propellant into chemical species in a thermodynamic phase that can be readily ionized. The propellant is commonly supplied from the propellant storage device to each of the chemical thruster and the electric thruster. The chemical thruster has a gas generator and a high thrust accelerator; the electric thruster has a plasma generator and a high specific impulse accelerator. The propellant supply arrangement is configured to control flow of the propellant from the propellant supply arrangement to the gas generator and the propellant conditioning arrangement, and a first flow path connects propellant supply arrangement with the gas generator, and a second flow path connects propellant supply arrangement with the plasma generator.

Abstract: Electrically large, stepped-wall or smooth-wall, direct-radiating horn antenna apparatus that may preferably be used in satellite spot beam applications. Exemplary electrically large smooth-wall horn antenna apparatus comprises one or more input ports, an electrically large output port, and a smooth-wall or stepped-wall tapered section having a spline-shaped profile extending from the input port(s) to the output port of the apparatus. The spline-shaped profile is preferably monotonic and is preferably configured to generate a spot beam. The spline-shaped profile may be configured to support multiple frequency bands, and dual simultaneous polarization having either linear or circular polarization. The spline-shaped profile is defined by spline knots, and, the knot radii form a nondecreasing sequence. Preferably, the spline-shaped profile comprises a piecewise cubic Hermite interpolating polynomial spline that interpolates the shape of curves between the spline knots.

Abstract: A large area, deployable flexible blanket photovoltaic solar array architecture for high power applications is disclosed. The structure is a modularized and scalable solar array system that provides high power level scalability. The structure is comprised of repeating, similar modular deployable roll-out solar array wings mounted in an opposing manner and along the length of a rigid, strong and efficiently packaged deployable backbone structure. The deployable roll-out solar array building block modular “winglet” elements can be comprised of either a rolled or z-folded flexible photovoltaic blanket configuration, and their structural deployment is motivated by the elastic strain energy of longitudinal roll-out booms. The backbone structure is comprised of a stiff deployable beam structure articulated that is deployed perpendicular with respect to the spacecraft sidewall and latched out.

Abstract: Apparatus and methods for raising the orbit of a satellite having electric propulsion thrusters, an Earth sensor and an inertial reference sensor such as a gyro. A satellite positioning system generates orbital data and a profile generator generates an ideal electric orbit raising profile of the satellite. The ideal profile is one that the satellite must follow so that the perigee, apogee and inclination of the satellite can be adjusted simultaneously in a mass-efficient manner. A state machine processes the ideal profile and a true anomaly to generate a desired electric orbit raising profile. Steering apparatus generates signals that are used to control the attitude of the satellite to follow the desired profile.