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: 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: 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: 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: Three-axis spacecraft momentum management is performed for a spacecraft traveling along a trajectory, by an actuator including at least one thruster disposed on a single positioning mechanism. As the spacecraft travels along the trajectory, a desired line of thrust undergoes a substantial rotation in inertial space. When the spacecraft is located at a first location on the trajectory, the single positioning mechanism orients the thruster so as to produce a first torque to manage stored momentum in at least one of a first and a second of the three inertial spacecraft axes. When the spacecraft is located at a second location on the trajectory, the single positioning mechanism orients the thruster so as to produce a second torque to manage stored momentum in at least a third of the three inertial spacecraft axes.

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.

Abstract: Spacecraft payload orientation steering is provided for an orbiting spacecraft in motion along an orbit track around a celestial body, the orbit track having a nominal inclination with respect to an equatorial orbit, a substantial eccentricity, and a drift angle with respect to the nominal inclination. Coordinates of an optimal payload target location as a function of a spacecraft position along the orbit track are determined, the target location being on the surface of the celestial body and having a substantial motion with respect to the surface and with respect to a spacecraft nadir. A payload of the spacecraft is substantially aligned with the determined coordinates by steering the satellite body to correct for at least one of the inclination drift angle, and the eccentricity, thereby adjusting the spacecraft orientation as a function of the spacecraft position along the orbit track.

Abstract: A photovoltaic solar cell assembly includes a bypass diode, a first and a second planar solar cell. Each of the first and the second solar cell includes a front facing side and a rear facing side, each rear facing side including a respective conductive surface, each front facing side including a respective current collector bar, and corresponding grid of metallic lines conductively coupled with the current collector bar. A first terminal of the bypass diode is electrically coupled with the conductive surface of the first solar cell. A second terminal of the bypass diode is electrically coupled with the current collector bar of the second solar cell. Electrical coupling of the bypass diode with the first solar cell and the second solar cell excludes any external wiring or busbar.

Abstract: A multiplexer includes a microstrip manifold, and a filter bank having at least two output filters. The multiplexer channelizes an input radio frequency (RF) band of electromagnetic energy into a set of output channels by way of the filter bank. The microstrip manifold has an input port that receives an input RF signal, and at least two output ports. The microstrip manifold distributes the input RF signal to each output port, each said output port being coupled to a respective one of the at least two output filters. The multiplexer may be an input multiplexer for a spacecraft communications payload system.

Abstract: An RF bandpass filter includes a cascaded series of a first subfilter and a second subfilter. Each subfilter includes a respective inverter, voltage-controlled capacitor and inductor. A first selected one of the first subfilter and the second subfilter is a pseudo low pass filter and a second selected one of the first subfilter and the second subfilter is a pseudo high pass filter. The RF bandpass filter is configured to separately control a bandwidth and center frequency of output RF energy. The bandwidth may be controlled to be substantially fixed over a significant substantial range. The center frequency and bandwidth are controlled by adjusting a voltage input to one or more of the voltage-controlled capacitors.

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: 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 extended forward and rotated to place the one or more antenna reflectors outboard of the spacecraft main body and further forward of the forward surface of the spacecraft.

Abstract: Spacecraft momentum management techniques are coordinated with station-keeping maneuvers or other delta-V maneuvers. A body stabilized spacecraft attitude is controlled, the spacecraft including at least one momentum/reaction wheel, and a set of thrusters. A first momentum storage deadband limit is adjusted, the adjustment being related to a first delta-V maneuver window. A momentum management strategy is executed with the adjusted first momentum storage deadband limit such that a first thruster firing that performs desaturation of the momentum/reaction wheel also provides velocity change beneficial to the first delta-V maneuver.

Abstract: A solar panel has a number of rectilinear photovoltaic solar cells. Each solar cell has four edges, a current collector bar having at least two conductively coupled collector bar segments, and a grid of electrodes conductively coupled to the collector bar. A first collector bar segment is substantially parallel to and proximate to a first edge of the solar cell, a second collector bar segment is substantially parallel to and proximate to a second edge of the solar cell, the second edge being orthogonal with respect to the first edge. In some disclosed techniques, the solar panel has a string of solar cells disposed on a surface of the solar panel in a substantially spiral or serpentine manner and no solar cell within the string is electrically connected to another solar cell in the string by any means other than a cell interconnect.

Abstract: Resource allocation to user terminals of a satellite system is optimized, the user terminals configured for data communication with a satellite via a common antenna beam. A resource is allocated, within the common antenna beam, to each user terminal i such that, when total available bandwidth A of the common antenna beam is not less than the total desired bandwidth ?=?i=1n ?i of the antenna beam, bi is no less than ?i, where: ?i is bandwidth demand at user terminal i, approximately equal to Ti-des/si; Ti-des is proportional to a throughput requirement by user terminal i; and si is an estimated spectral efficiency of user terminal i. When A is less than ?, bandwidth bi is allocated to each user terminal such that a number of user terminals supplied respective bandwidth not less than ?i is maximized.

Abstract: Various roll-up contamination covers for shielding sensors and other sensitive equipment from particulate contamination are provided. Such covers may be provided by using a sheet of flexible material that has an elastically stable state of a spiral torsion spring, e.g., a clock spring shape. The spiral torsion spring may be anchored to a frame along one end that is substantially parallel to the center axis of the spiral torsion spring, and may be unrolled into a substantially unrolled state so as to cover an aperture in the frame. A movable release mechanism may be engaged with the unrolled end of the spiral torsion spring to prevent the spiral torsion spring from returning to the elastically stable state. When the release mechanism is moved to release the unrolled end of the spiral torsion spring, the spiral torsion spring may roll back into the elastically stable state and uncover the aperture.

Abstract: A dual mode dielectric resonator (DR) filter has a first DR, and is configured to operate at a HE12? mode within a first frequency band while exhibiting a Q factor of no less than 5000. A first characteristic size of the first DR may be substantially similar to a size of a second DR, where the second DR is configured to operate in a conventional DR filter at a HE11? mode within a second frequency band, the second frequency band being substantially lower than the first frequency band.

Abstract: A deployable solar panel array featuring in-line solar panels and side solar panels, where the side solar panels are configured to deploy in a staggered fashion after deployment of the in-line panels. A passive deployment mechanism governs the deployment sequence.

Abstract: A hold-down mechanism for a steerable spacecraft appendage, the appendage being coupled to a spacecraft structure with a positioning mechanism, is configured (1) to support, when in a hold-down mode, the appendage at a first position substantially fixed with respect to the spacecraft; (ii) release, upon receipt of a signal, the appendage, thereby enabling the positioning mechanism to steer the spacecraft appendage; and (iii) retract from the appendage without regard to whether the appendage remains substantially in the first position. The first position may result in the spacecraft appendage being aligned in a nominal operating location and orientation, so that the antenna positioning mechanism is not required to initially deploy or otherwise reorient the appendage.