Abstract: A scalable, extensible, multi-tenancy multi-mission configurable spacecraft system is provided that allows applications to be deployed and managed across many spacecraft. One embodiment includes a plurality of satellites in orbit, where each satellite includes an antenna, a memory configured to store a non-virtualized operating system and one or more software applications, and a processor connected to the antenna and the memory. The processor is configured to run the non-virtualized operating system and to run the one or more software applications. The processors and the applications can be managed by ground terminals or other satellites.

Abstract: A passively damped mechanical system is disclosed, for example for use in aerospace applications where vibration can adversely affect navigational and operational instruments. In one example, the passively damped mechanical system includes an end fitting of a strut used to connect a structural element to a payload. The end fitting may include outer and inner cylindrical hubs, with a space between the outer and inner cylindrical hub at least partially filled with a viscoelastic material. In a further example, the passively damped mechanical system includes legs used to connect a structural element to a bracket configured to support a payload. Each leg may include a hollow interior having a lattice structure to add strength and a viscoelastic material to provide passive damping.

Abstract: A universal test port is connected to the different functional sub-systems of a spacecraft, allowing the sub-systems to be tested from a single location of an assembled spacecraft. The universal test port is mounted on an external surface of the spacecraft and configured to connect to the different functional sub-systems (such as power, propulsion, and command and data handling, for example) of the assembled spacecraft, allowing for the streamlining of testing operations by electrical ground system equipment during assembly, integration, and test (AIT) operations and reducing the risk of collateral damage to spacecraft hardware during testing in AIT.

Abstract: A satellite includes a plurality of thrusters disposed about the satellite, each of the plurality of thrusters having a minimum thruster firing time, and a control circuit connected to the plurality of thrusters. The control circuit is configured to identify violations of the minimum thruster firing time in a non-compliant thruster firing pattern selected to achieve a specified movement, generate a plurality of compliant thruster firing patterns by replacing each of the violations of the non-compliant thruster firing pattern by zero and a minimum time in different combinations, select a compliant thruster firing pattern from the plurality of compliant thruster firing patterns to produce a satellite movement that is within a predetermined range of the specified movement, and cause the plurality of thrusters to fire according to the compliant thruster firing pattern.

Abstract: A universal external port is proposed to add new functionality to or replace existing functionality of an already deployed spacecraft (e.g., a satellite in orbit). The universal external port is mounted on an external surface of the spacecraft and configured to connect to different types of external modules that have different functions, without removing components from the spacecraft other than one or more components of the universal external port. A communication interface onboard the spacecraft is configured to wirelessly receive a software patch from an entity remote from the spacecraft (e.g., from a ground terminal or other spacecraft) to program the spacecraft to change operation of the spacecraft to utilize the external module when the external module is connected to the universal external port.

Abstract: A solid state power amplifier uses a Doherty power amplifier that can be implemented as a monolithic microwave integrated circuit. By adjusting the DC bias of the amplifying stages in each branch of the Doherty amplifier, the output power, linearity, and DC power can be adjusted to provide a specified output, where the specification for the output can include the maintaining of desired DC power and linearity. The Doherty power amplifier can be used in a satellite payload or other application utilizing solid state power amplifiers, while providing the proper amount of RF output power and DC power. A single amplifier can have its bias levels adjusted for different output levels, helping to minimize the number of designs that are required for a given satellite payload, reducing the variety of parts in a satellite payload.

Abstract: A solid state power amplifier uses a Doherty power amplifier that can be implemented as a monolithic microwave integrated circuit. By adjusting the DC bias of the amplifying stages in each branch of the Doherty amplifier, the output power, linearity, and DC power can be adjusted to provide a specified output, where the specification for the output can include the maintaining of desired DC power and linearity. The Doherty power amplifier can be used in a satellite payload or other application utilizing solid state power amplifiers, while providing the proper amount of RF output power and DC power. A single amplifier can have its bias levels adjusted for different output levels, helping to minimize the number of designs that are required for a given satellite payload, reducing the variety of parts in a satellite payload.

Abstract: A method of roll steering of a spacecraft to align an aspect of the spacecraft, such as the surface of solar arrays carried by the spacecraft, to the sun, is described. The roll steering occurs only when the sun is at an angle (?) relative to the orbital plane of the spacecraft and when the spacecraft is not eclipsed by a body it is orbiting. This dayside-only roll steering of the spacecraft increases the power efficiency of the spacecraft. A spacecraft may include a controller which causes an attitude control subsystem to steer the spacecraft about a roll axis to position the surface of the solar array such that an axis normal to the surface of the solar array is aligned with the direction to a sun when the sun is visible to the spacecraft, and maintain a fixed orientation of the spacecraft about the roll axis when the sun is not visible to the spacecraft.

Abstract: A scalable, extensible, multi-tenancy multi-mission configurable spacecraft system is provided that allows applications to be deployed and managed across many spacecraft. One embodiment includes a plurality of satellites in orbit, where each satellite includes an antenna, a memory configured to store a non-virtualized operating system and one or more software applications, and a processor connected to the antenna and the memory. The processor is configured to run the non-virtualized operating system and to run the one or more software applications. The processors and the applications can be managed by ground terminals or other satellites.

Abstract: A wireless communication platform utilizes flexible bandwidth assignment to re-allocate bandwidth between spot beams. The platform may assign a first combination of frequency and polarization (FP) to a first spot beam and a second combination of frequency and polarization to a second spot beam that is adjacent and at least partially overlapping the first spot beam. The platform may assign to the first spot beam a reserved combination of frequency and polarization during a first time period, and at second time, assign the reserved combination to the second spot beam. The platform may also assign the reserved combination simultaneously to adjacent spot beams by managing user of the reserved combination by geographically isolated terminals in the spot beams. The platform may further assign different portions of the reserved combination to adjacent spot beams without geographical limitations.

Abstract: A wireless communication system includes frequency reuse between terminals in common coverage regions using a multiple satellite architecture with spatial diversity. Different terminals may be associated with different ones of the satellites such that a common frequency can be reused by the different terminals. A gateway may communicate with a first satellite using a feeder beam having an overlapping geographic coverage region with a user beam used for communication between a set of user terminals and a second satellite. Spatial diversity is provided between the satellites, and the feeder beam and the user beam operate at common frequencies within the overlapping coverage region. In this manner, the bandwidth of both satellites at the common coverage region is used to increase the available capacity.

Abstract: A wireless communication platform utilizes flexible bandwidth assignment to re-allocate bandwidth between spot beams. The platform may assign a first combination of frequency and polarization (FP) to a first spot beam and a second combination of frequency and polarization to a second spot beam that is adjacent and at least partially overlapping the first spot beam. The platform may assign to the first spot beam a reserved combination of frequency and polarization during a first time period, and at second time, assign the reserved combination to the second spot beam. The platform may also assign the reserved combination simultaneously to adjacent spot beams by managing user of the reserved combination by geographically isolated terminals in the spot beams. The platform may further assign different portions of the reserved combination to adjacent spot beams without geographical limitations.