Abstract: An electrical power system has a dual battery configuration that enables sufficient power supply for a spacecraft bus and a payload module being carried by the spacecraft. During a sunlight power mode, power is drawn from a solar array of the bus to power a low-discharge payload of the spacecraft and a high-discharge payload of a payload module. During the sunlight power mode, a low rate discharge battery and a high rate discharge battery are charged by a battery charge management unit of the spacecraft bus. During an eclipse power mode, the low rate discharge battery powers the low-discharge payload of the spacecraft and the high rate discharge battery powers the high-discharge payload of the payload module. The high-rate discharge battery may also be used to power the high-rate discharge payload in the sunlight power mode to meet its high current demands to meet a flexible mission operations.

Abstract: An electrical power system has a dual battery configuration that enables sufficient power supply for a spacecraft bus and a payload module being carried by the spacecraft. During a sunlight power mode, power is drawn from a solar array of the bus to power a low-discharge payload of the spacecraft and a high-discharge payload of a payload module. During the sunlight power mode, a low rate discharge battery and a high rate discharge battery are charged by a battery charge management unit of the spacecraft bus. During an eclipse power mode, the low rate discharge battery powers the low-discharge payload of the spacecraft and the high rate discharge battery powers the high-discharge payload of the payload module. The high-rate discharge battery may also be used to power the high-rate discharge payload in the sunlight power mode to meet its high current demands to meet a flexible mission operations.

Abstract: Described herein is a thrust system for a vehicle that includes at least three electrical power controllers, at least four electrical switches each configured to receive electrical power from at least one of the at least three electrical power controllers, and at least three thrusters each configured to receive electrical power from at least one of the at least three electrical switches. The at least four electrical switches are operable to switch a supply of electrical power from any of the at least three electrical power controllers to any one of the at least three thrusters.

Abstract: Thruster grid clear circuits and methods to clear thruster grids are disclosed. An example apparatus includes a low voltage grid clear circuit to apply first energy to a grid at a first voltage, and a high voltage grid clear circuit to detect a failure of the applied energy to clear a short circuit condition of the grid and to apply second energy to the grid at a second voltage higher than the first voltage.

Abstract: Described herein is a thrust system for a vehicle that includes at least three electrical power controllers, at least four electrical switches each configured to receive electrical power from at least one of the at least three electrical power controllers, and at least three thrusters each configured to receive electrical power from at least one of the at least three electrical switches. The at least four electrical switches are operable to switch a supply of electrical power from any of the at least three electrical power controllers to any one of the at least three thrusters.

Abstract: Described herein is a thrust system for a vehicle that includes at least three electrical power controllers, at least four electrical switches each configured to receive electrical power from at least one of the at least three electrical power controllers, and at least three thrusters each configured to receive electrical power from at least one of the at least three electrical switches. The at least four electrical switches are operable to switch a supply of electrical power from any of the at least three electrical power controllers to any one of the at least three thrusters.

Abstract: Described herein is a shaft assembly for a rotary switch that includes a shaft made from an electrically non-conductive material. The shaft includes at least one circumferential groove that has a generally T-shaped cross-section. The shaft assembly also includes at least one conductive ring segment made from an electrically conductive material positioned within the circumferential groove. The conductive ring segment has a generally T-shaped cross-section. Additionally, the shaft assembly includes a bonding adhesive that is positioned between the circumferential groove and the conductive ring segment.

Abstract: A method, system, and apparatus are disclosed for autonomous lithium-ion battery protection. In particular, the present disclosure teaches a system that provides for automatic protection of lithium-ion batteries from damage due to deep discharge and, in some embodiments, from recharging in low temperatures. The disclosed system employs internal logic, autonomous switches and, in some embodiments, heaters to protect the battery without any need for spacecraft monitoring or control intervention. The system uses one or more dedicated strings of solar array cells to, in some embodiments, preheat, and to recharge the battery. The system is completely self contained in the battery with the only additional interface being for the string(s) of the solar array cells that are used to provide dedicated and reliable power to the system.

Abstract: Described herein is a thrust system for a vehicle that includes at least three electrical power controllers, at least four electrical switches each configured to receive electrical power from at least one of the at least three electrical power controllers, and at least three thrusters each configured to receive electrical power from at least one of the at least three electrical switches. The at least four electrical switches are operable to switch a supply of electrical power from any of the at least three electrical power controllers to any one of the at least three thrusters.

Abstract: A gridded ion propulsion system comprising two power controllers, four ion thrusters, and two switch assemblies. One switch assembly is connected to the two power controllers and to two of the four ion thrusters. The other switch assembly is connected to the two power controllers and to the other two ion thrusters. Each switch assembly has first and second switching states which can be selected to enable either power controller to supply power to any one of the four ion thrusters. Each switch assembly comprises a respective movable body and a respective multiplicity of switches which change state in unison when the movable body changes position. For example, the movable body may be a rotatable hollow shaft driven by a stepper motor.

Abstract: Described herein is a shaft assembly for a rotary switch that includes a shaft made from an electrically non-conductive material. The shaft includes at least one circumferential groove that has a generally T-shaped cross-section. The shaft assembly also includes at least one conductive ring segment made from an electrically conductive material positioned within the circumferential groove. The conductive ring segment has a generally T-shaped cross-section. Additionally, the shaft assembly includes a bonding adhesive that is positioned between the circumferential groove and the conductive ring segment.

Abstract: Thruster grid clear circuits and methods to clear thruster grids are disclosed. An example apparatus includes a low voltage grid clear circuit to apply first energy to a grid at a first voltage, and a high voltage grid clear circuit to detect a failure of the applied energy to clear a short circuit condition of the grid and to apply second energy to the grid at a second voltage higher than the first voltage.

Abstract: A relay telemetry system enables an ion propulsion system to self-test the critical relay configuration prior to supplying high-voltage power to any thruster. This test detects whether any critical relay has failed to switch properly or is in the wrong configuration. In the test mode, an onboard computer initiates the application of a low-voltage test voltage (nominally 15 V) to the high-voltage circuits (when the high voltage is off) by a stimulus circuit. Sensing circuits detect the inputs and outputs of the system connections in response to this stimulus. If the test voltage appears on an input or output where it is not expected, then a relay fault has occurred and will be detectable in telemetry sent back to the onboard computer.

Abstract: Thruster grid clear circuits and methods to clear thruster grids are disclosed. An example apparatus includes a low voltage grid clear circuit to apply first energy to a grid at a first voltage, and a high voltage grid clear circuit to detect a failure of the applied energy to clear a short circuit condition of the grid and to apply second energy to the grid at a second voltage higher than the first voltage.

Abstract: A method, system, and apparatus are disclosed for autonomous lithium-ion battery protection. In particular, the present disclosure teaches a system that provides for automatic protection of lithium-ion batteries from damage due to deep discharge and, in some embodiments, from recharging in low temperatures. The disclosed system employs internal logic, autonomous switches and, in some embodiments, heaters to protect the battery without any need for spacecraft monitoring or control intervention. The system uses one or more dedicated strings of solar array cells to, in some embodiments, preheat, and to recharge the battery. The system is completely self contained in the battery with the only additional interface being for the string(s) of the solar array cells that are used to provide dedicated and reliable power to the system.

Abstract: The invention discloses a method and device for clearing an ion thruster grid of contaminants. A typical method includes applying a power supply to a grid to clear contaminants, monitoring an energy applied to the grid of the applied power supply and suspending application of the power supply to the grid after the monitored energy substantially reaches a predetermined value. A typical device includes a controller for applying a power supply to a grid to clear the grid of contaminants and a timer for monitoring an energy applied to the grid of the applied power supply and suspending application of the power supply to the grid after the monitored energy substantially reaches a predetermined value.

Abstract: The invention discloses a method and device for clearing an ion thruster grid of contaminants. A typical method includes applying a power supply to a grid to clear contaminants, monitoring an energy applied to the grid of the applied power supply and suspending application of the power supply to the grid after the monitored energy substantially reaches a predetermined value. A typical device includes a controller for applying a power supply to a grid to clear the grid of contaminants and a timer for monitoring an energy applied to the grid of the applied power supply and suspending application of the power supply to the grid after the monitored energy substantially reaches a predetermined value.

Abstract: A method (10) and apparatus (20, 40, 50) for driving a high voltage relay wherein a command pulse (24) is divided into a series of pulses (25) before being processed by a transformer (26). The method and apparatus of the present invention allow a significantly smaller transformer to be used in the relay driver thereby effecting significant size and weight reductions on-board a satellite system.

Abstract: An electronic component operating at high voltage is mounted to the top side of an insulating platform, which in turn is supported from a chassis by a pedestal. The insulating platform provides a long surface path conduction distance of the electronic component to the chassis and to other components mounted to the chassis. The platform-mounted electronic component is thereby insulated against arcing and damaging the other components.