Abstract: A spacecraft includes a payload subsystem including a digital channelizer. The digital channelizer provides at least a portion of spacecraft command or telemetry functionality. The spacecraft may optionally also include a telemetry and command (T&C) subsystem, the T&C subsystem including one or more of a command receiver, a command decoder, a telemetry encoder and a telemetry transmitter. The digital channelizer may be communicatively coupled with at least one of the command receiver, the command decoder, the telemetry transmitter and the telemetry encoder.

Abstract: A satellite comprises an antenna system configured to provide a plurality of spot beams including one or more small spot beams illuminating a first region of a coverage area, one or more large spot beams illuminating a second region of the coverage area separate from the first region and one or more intermediate sized spot beams illuminating a transition region of the coverage area that is located between the first region and the second region so that the one or more small spot beams are separated from the one or more large spot beams by the one or more intermediate sized spot beams. The one or more intermediate sized spot beams serve to mitigate C/I for the one or more spot beams.

Abstract: This disclosure provides systems, methods and apparatus for determining beamforming coefficients that correct for pointing errors. In one aspect, a subsystem of a ground station can receive calibration signals from a satellite. The properties of the calibration signals can be measured and used to determine the pointing error of the satellite. Beamforming coefficients based on the pointing error can be provided by the ground station to the satellite.

Abstract: Techniques for testing a component for compatibility with a depressurization profile associated with a launch vehicle payload fairing during ascent are disclosed. A pressure of air or other gas within a pressure vessel containing the component is raised to a first value substantially higher than one atmosphere absolute pressure. The air/gas pressure within the pressure vessel is lowered, by venting into the ambient atmosphere, at a rate simulating or demonstrating margin with respect to the launch vehicle payload fairing depressurization profile. The component is inspected for damage. The component may be a panel including a honeycomb core sandwiched between two faceskins, the panel having a planar area in excess of twenty five square feet.

Abstract: A communication system uses resources (including a first signal path and a second signal path) in a first roundtrip direction for a first set of gateways and subscriber terminals while concurrently using the same resources (including the first signal path and the second signal path) in a second roundtrip direction for a second set of gateways and subscriber terminals.

Abstract: Techniques for deorbiting a satellite include executing an orbit transfer maneuver that transfers the satellite from an operational orbit to an interim orbit. The operational orbit is substantially geosynchronous and has (i) an inclination of greater than 70 degrees; (ii) a nominal eccentricity in the range of 0.25 to 0.5; (iii) an argument of perigee of approximately 90 or approximately 270 degrees; (iv) a right ascension of ascending node of approximately 0; and (v) an operational orbit apogee altitude. The interim orbit has an initial second apogee altitude that is at least 4500 km higher than the first apogee altitude, and the interim orbit naturally decays, subsequent to the orbit transfer maneuver, such that the satellite will reenter Earth's atmosphere no longer than 25 years after completion of the orbit transfer maneuver.

Abstract: Latching or locking deployment hinges are provided that include a latch mechanism, a spring-loaded tensioning device, and a trigger mechanism. The trigger mechanism and the spring-loaded tensioning device are configured to transfer the compressed spring load in the spring-loaded tensioning device to the latch mechanism once the hinge has closed sufficiently far enough to latch together, thus inducing a pre-load through the latch mechanism that eliminates gapping in the hinge interface. The hinges may be sprung or actuated using a powered drive mechanism.

Abstract: An array of antenna feed elements includes a plurality of horns, each horn having an aperture and configured for transmission of electromagnetic energy therethrough. At least a first horn is configured with an electrically conductive external surface proximate to the aperture, the external surface contoured so as to reduce mutual coupling between the first horn and an adjacent horn. Where the electromagnetic energy is within a radio frequency (RF) band, the external surface is contoured so as to provide an abrupt change in a gap dimension between the first horn and an adjacent horn, the change occurring at a distance behind the aperture of equal to a multiple of one half the characteristic wavelength of the RF band.

Abstract: Techniques for placing a satellite into a highly inclined elliptical operational orbit (HIEO) 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, and to be substantially lower than the operational orbit. 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: A mode filter provides a low-loss transmission path for RF signals propagating in a first mode, while substantially suppressing at least one second mode. The mode filter includes a proximal port and a distal port, having a respective characteristic cross sectional dimension Dp1 and Dp2, and an electrically conductive hollow tube having a longitudinal axis that extends a length L between a distal end of the proximal port and a proximal end of the distal port. A cross section transverse to the longitudinal axis is non-uniform along length L and has a minimum internal characteristic dimension Dmin at least at a first longitudinal position and a maximum internal characteristic dimension Dmax at least at a second longitudinal position. The mode filter is configured to suppress the at least one second mode by at least 5 dB, and Dmax is less than 2.5 times the greater of Dp1 and Dp2.

Abstract: Techniques for testing whether a bond strength between a faceskin of a panel and a core of the panel exceeds a threshold value are disclosed. The testing includes: adhering a first surface of a sacrificial layer to a pull stub of a flatwise tensile (FWT) test apparatus by way of a first adhesive interface; adhering the second surface of the sacrificial layer to the panel faceskin by way of a second adhesive interface; operating the FWT test apparatus so as to gradually increase a FWT load on the faceskin; terminating the test upon the first to occur of separation of any one or more of the first adhesive interface, the second adhesive interface, the sacrificial layer and separation of the faceskin from the core; and determining that the bond strength exceeds the threshold value when separation of the faceskin from the core is not the first to occur.

Abstract: Present location information about a present location of a mobile terminal is obtained, as is destination information about a target destination for the mobile terminal, wherein the target destination can be a waypoint destination or a final destination for the mobile terminal. Also obtained is wireless communication coverage information about wireless communication coverage associated with one or more geographic regions between the present location of the mobile terminal and the target destination for the mobile terminal. In dependence on the wireless communication coverage information, a navigational route is determined for the mobile terminal that mitigates a probability that the mobile terminal will lose a specific type of communication capability while travelling between the present location of the mobile terminal and the target destination for the mobile terminal.

Abstract: A satellite includes a first communication path for communicating with one or more gateways using a first frequency band while communicating with a set of the user terminals using a user frequency band and a second communication path for communicating with the one or more gateways using a second frequency band while communicating with at least a subset of the user terminals using the user frequency band. The second frequency band has a lower capacity than the first frequency band. Communication between the one or more gateways and the satellite can be switched between the first communication path and the second communication path for any of a number of reasons including as part of an incremental roll-out of services, in response to degradation in link quality or other reason.

Abstract: Interference information is obtained from one or more interference information sources external to a particular communication system, wherein the interference information is indicative of non-weather related interference that can adversely affect efficacy of the particular communication system. Configurable link parameters of the particular communication system are dynamically adapted and/or resources of the particular communication system are dynamically allocated based on the interference information obtained from the interference information source(s) that is/are external to the particular communication system. Such embodiments can advantageously be performed proactively to prevent or mitigate adverse effects of non-weather related interference on the efficacy of the particular communication system.

Abstract: Present location information about a present location of a mobile terminal is obtained, as is destination information about a target destination for the mobile terminal, wherein the target destination can be a waypoint destination or a final destination for the mobile terminal. Also obtained is wireless communication coverage information about wireless communication coverage associated with one or more geographic regions between the present location of the mobile terminal and the target destination for the mobile terminal. In dependence on the wireless communication coverage information, a navigational route is determined for the mobile terminal that mitigates a probability that the mobile terminal will lose a specific type of communication capability while travelling between the present location of the mobile terminal and the target destination for the mobile terminal.

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 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.