Abstract: Technology is disclosed herein for deploying stacked spacecraft. When the spacecraft are stacked corresponding z-axis magnetic torque rods of the spacecraft will align with each other along a z-axis. Thus, collectively the stack of spacecraft have one or more sets of magnetic torque rods aligned with the z-axis. Just prior to deploying the spacecraft the one or more sets of magnetic torque rods are operated to hold the stack of spacecraft together. For example, the north magnetic pole of the magnetic torque rod in one spacecraft may face the south magnetic pole of the magnetic torque rod in an adjacent spacecraft. To deploy the top spacecraft, the polarity of the z-axis magnetic torque rod(s) in the top spacecraft is/are reversed. After the spacecraft is clear of the stack the magnetic torque rod(s) in the deployed spacecraft may be de-activated. Then another spacecraft may be deployed in a similar manner.

Abstract: A connector loading device may comprise a receptacle, a plurality of light sources, and a controller. The receptacle may comprise a first plurality of holes. The first plurality of holes are configured to respectively line up with a second plurality of holes in a connector when the connector is inserted in the receptacle. Each one of the first plurality of holes comprises a respective and corresponding one of a plurality of unique indexes. The plurality of light sources respectively correspond to the first plurality of holes. Each one of the plurality of light sources, when initiated, is configured to illuminate light from a bottom of its respective one of the first plurality of holes through a top of its respective one of the first plurality of holes. The controller is configured to receive an input and initiate a one of the plurality of light sources corresponding to the index.

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 radiator structure for a satellite is provided. A first radiator panel adapted to be positioned on a first side of a central body, and a second radiator panel adapted to be positioned on a second side of the central body. Other implementations include a third radiator panel positioned on a third side of the central body. The apparatus also includes at least one heat pipe embedded between a first face and a second face of each radiator panel and extending from the first radiator panel through the first radiator panel and through the second radiator panel. The heat pipe structurally supports the first radiator panel and the second radiator panel relative to the intermediate radiator panel. A method of manufacturing a radiator structure is also provided.

Abstract: To facilitate on-orbit servicing, such as for a refueling operation, techniques are presented for a servicing satellite to cut through the multi-layer insulation blanket of a client satellite to provide access to the client satellite without releasing unacceptable quantities of foreign object debris from the multi-layer insulation. The serving satellite includes a sealing tool, such as a pair of heater rollers, that apply pressure and heat to the insulating blanket to melt the inner layers and seal the outer layers together. The servicing satellite can then use a cutting tool to cut the sealed region and access the client satellite.

Abstract: An electric propulsion simulator console (EPSC) which electronically simulates an electric propulsion assembly of a spacecraft as well as propulsion fuel control components and positioning components of the spacecraft. The EPSC simulates a spacecraft thruster electrical interface can test four thruster interfaces simultaneously and continuously. The simulator additionally facilitates the testing of spacecraft fault detection, isolation, and recovery by simulating failed magnet circuits, open anode paths, and flameout conditions. The EPSC includes an electrical propulsion unit load simulator adapted to receive propulsion unit control signals from a spacecraft under test and a spacecraft propulsion unit positioner simulator the simulator adapted to display a simulated state of three axes of movement for at least one propulsion unit positioner responsive to positioning signals received from the spacecraft under test.

Abstract: Technology is disclosed herein for preventing or at least significantly reducing shock to spacecraft such as satellites when releasing a hold-down rod assembly that clamps the spacecraft to, for example, a launch vehicle adaptor. The hold-down rod assembly has tension rods that may be pre-loaded at considerable tension in order to hold down a stack of spacecraft in a launch configuration. In an embodiment, pneumatic actuators are used to slowly release the tension in the tension rods. Therefore, shock to the spacecraft is prevented or at least significantly reduced.

Abstract: A solar array structure for a spacecraft includes one or a pair of flexible blanket or other foldable solar arrays (such as flexible panels) and a deployable frame structure. The deployable frame structure includes a T-shaped yoke structure, a T-shaped end structure, and one or more rigid beams, the T-shaped yoke structure connectable to the spacecraft. When deployed, the frame structure tensions the flexible blanket solar array or arrays between the T-shaped yoke structure and the T-shaped end structure. When stowed, the flexible blanket solar array or arrays are folded in an accordion manner to form a stowed pack or packs between the cross-member arms of the T-shaped yoke structure and the T-shaped end structure, also stowed in its own Z-fold arrangement. The cross-member arms of the T-shaped end structure can include a solar array that can provide power before deployment while the flexible blanket solar array is stowed.

Abstract: Technology is disclosed herein for deploying stacked spacecraft. When the spacecraft are stacked corresponding z-axis magnetic torque rods of the spacecraft will align with each other along a z-axis. Thus, collectively the stack of spacecraft have one or more sets of magnetic torque rods aligned with the z-axis. Just prior to deploying the spacecraft the one or more sets of magnetic torque rods are operated to hold the stack of spacecraft together. For example, the north magnetic pole of the magnetic torque rod in one spacecraft may face the south magnetic pole of the magnetic torque rod in an adjacent spacecraft. To deploy the top spacecraft, the polarity of the z-axis magnetic torque rod(s) in the top spacecraft is/are reversed. After the spacecraft is clear of the stack the magnetic torque rod(s) in the deployed spacecraft may be de-activated. Then another spacecraft may be deployed in a similar manner.

Abstract: A Radio Frequency Identification (“RFID”) sensor harvests power from a RFID interrogation signal received from a RFID reader and harvests power from surrounding RF energy which is at a different frequency than the RF interrogation signal. The harvested power is used to operate the sensor and transmit data sensed by the sensor.

Abstract: An orbital satellite has a bus formed of a bus module and a payload module. Both the bus module and the payload modules may include a pair of panels integrally formed at an angle of for example 90° with respect to each other. Components and electronics supporting the satellite systems may be mounted on the panels of the bus and payload modules. Heat generated by the components and electronics are conducted between panels of the bus module and/or payload module. Sufficient heat transfer between panels occurs as a result of their being integrally formed with each other.

Abstract: A solar array structure, such as for a spacecraft, uses thin solar array panels that, when in a stowed configuration, are stiffened by being bent or curved in one direction to be shaped like a section of a cylinder and placed within a rigid structural frame. As a curved solar panel is not as efficient as a flat panel directly facing the sun, the solar array panels are curved in their stowed configuration for launch only, but flatten after deployment by use of a partially flexible structural frame, where a rectangular frame is made of two opposing rigid sides and two opposing flexible sides, with a thin flexible solar panel attached to rigid sides only. The rigid sides are compressed during stowage to curve the panel before hold-down tensioning. The structure and panels return to their flat free state configuration after release.

Abstract: A solar array structure for a spacecraft is based on a modular approach, allowing for arrays to be designed, and designed to be modified, and manufactured in reduced time and with reduced cost. The embodiments for the solar array are formed of multiple copies of a “bay” of a multiple strings of solar array cells mounted on semi-rigid face-sheet structural elements. The bays are then placed into frame structures made of tubes connected by nodes to provide an easily scalable, configurable, and producible solar array wing structure. This allows for rapid turnaround of program specific designs and proposal iterations that is quickly adaptable to new/future PhotoVoltaic (PV) technologies and that can create uniquely shaped (i.e., not rectangular) arrays, allowing for mass production with simple mass producible building blocks.

Abstract: An apparatus includes an integral, additively manufactured, actuation device having a rigid portion comprising a shaped structural member and a flexible portion comprising a helical torsion spring. In a spacecraft application, a spacecraft appendage may be coupled with a deployment mechanism, the deployment mechanism including at least one integral, additively manufactured, actuation device having a rigid portion comprising a shaped structural member and a flexible portion comprising a helical torsion spring.

Abstract: An attitude control system for a satellite is presented that can determine on time values for attitude control thrusters without use of attitude rate sensors, such as those based on gyros. The attitude control systems uses the attitude values from a star tracker to determine both attitude adjustment values and attitude adjustment rate values directly from the star tracker values, where the processing is performed using quaternions. From the attitude adjustment values and attitude adjustment rate values, a set of thruster on time values are determined.

Abstract: A solar array structure for a spacecraft is based on a modular approach, allowing for arrays to be designed, and designed to be modified, and manufactured in reduced time and with reduced cost. The embodiments for the solar array are formed of multiple copies of a “bay” of a multiple strings of solar array cells mounted on semi-rigid face-sheet structural elements. The bays are then placed into frame structures made of tubes connected by nodes to provide an easily scalable, configurable, and producible solar array wing structure. This allows for rapid turnaround of program specific designs and proposal iterations that is quickly adaptable to new/future PhotoVoltaic (PV) technologies and that can create uniquely shaped (i.e., not rectangular) arrays, allowing for mass production with simple mass producible building blocks.

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 satellite observation system and method of deploying a satellite system are disclosed. The system includes a plurality of observation satellites comprising one or more sensors, each of the plurality of observation satellites configured with at least a solar array and a mechanical stabilization element. Each of the plurality of observation satellites is constructed without positioning components. The plurality of observation satellites is positioned in a dawn/dusk sun-synchronous orbital plane about a celestial body such that the one or more observation sensors are oriented toward the celestial body.

Abstract: A voltage measurement apparatus for a spacecraft thruster includes a thruster interface having a platform and at least one spacer element configured to attach the platform to the thruster. At least one probe is mounted to the thruster interface with the probe configured to engage an anode assembly of the thruster when the thruster interface is attached to the thruster. The apparatus also includes voltage metering circuitry coupled to the at least one probe, the voltage metering circuitry configured to be powered by the spacecraft thruster when the spacecraft thruster is powered on.

Abstract: Technology is disclosed herein for reverse current protection for a photovoltaic module string. An apparatus has a switch connected between each respective PV module string and a power bus. A control circuit closes a set of the switches to connect a set of the PV module strings to the power bus to transfer power from the set of the photovoltaic PV module strings to the power bus. The control circuit determines whether a reverse current flows in the direction from the power bus to any of the PV module strings. The control circuit maintains the switch associated with a particular PV module string in an open state to prevent reverse current from flowing in the particular PV module string responsive to a determination that a reverse current flows in the particular PV module string when the particular PV module string is connected to the power bus.