Abstract: An Earth monitoring system comprises a satellite constellation (310) and a schedule calculation module (302) located on Earth. The schedule calculation module (302) may be configured to implement a satellite management method receiving a request post-launch for a location to be imaged; recalculating an existing schedule of the satellites to provide an updated schedule that includes imaging the location; and providing the updated schedule for transmission to one or more of the satellites.

Abstract: A method of operating a spacecraft propulsion system comprises injecting electrons into the plasma surrounding the spacecraft prior to creating the stream of ions, and after commencing creation of the ion stream, continuing the injection of electrons in an amount sufficient to maintain the spacecraft at a positive potential. This method may be implemented in a single thruster. In spacecraft with multiple thrusters the same method may be implemented in each thruster. Where the propulsion system comprises a plurality of thrusters, the method may comprise: operating at least one of the thrusters as a drive thruster, and operating at least one of the thrusters as an auxiliary or “reserve” thruster. The electron source of the at least one auxiliary thruster may be operated before creation of the ion stream to inject the electrons into the plasma surrounding the spacecraft.

Abstract: A satellite comprising a body and a generally planar structure extending from the body. One or more radio frequency “RF” antennas, an amplification system for rf signals, and a power distribution system for the amplification system are mounted on the generally planar structure. Two or all of the power distribution system, the one or more RF antennas and the amplification system are arranged on respective parallel boards forming part of the generally planar structure. One or more of the parallel boards and the components mounted thereon may be connected to another similar board to form, respectively a larger power distribution system, antenna array or amplification system, for example arranged in a plurality of modules, each comprising at least one antenna, at least one power distribution system and at least one amplifier supported on at least two respective boards.

Abstract: An Earth monitoring system comprises a satellite constellation (310) and a schedule calculation module (302) located on Earth. The schedule calculation module (302) may be configured to implement a satellite management method receiving a request post-launch for a location to be imaged; recalculating an existing schedule of the satellites to provide an updated schedule that includes imaging the location; and providing the updated schedule for transmission to one or more of the satellites.

Abstract: A satellite comprises a body and a generally planar structure extending from the body. One or more radio frequency “RF” antennas, an amplification system for RF signals, and a power distribution system for the amplification system are mounted on the generally planar structure. Two or all of the power distribution system, the one or more RF antennas and the amplification system are arranged on respective parallel boards (310, 312, 314) forming part of the generally planar structure (300). One or more of the parallel boards (310, 312, 314) and the components mounted thereon may be connected to another similar board to form, respectively, a larger power distribution system, antenna array or amplification system, for example arranged in a plurality of modules, each comprising at least one antenna, at least one power distribution system and at least one amplifier supported on at least two respective boards.

Abstract: A method of operating a spacecraft propulsion system comprises injecting electrons into the plasma surrounding the spacecraft prior to creating the stream of ions, and after commencing creation of the ion stream, continuing the injection of electrons in an amount sufficient to maintain the spacecraft at a positive potential. This method may be implemented in a single thruster. In spacecraft with multiple thrusters the same method may be implemented in each thruster. Where the propulsion system comprises a plurality of thrusters, the method may comprise: operating at least one of the thrusters as a drive thruster, and operating at least one of the thrusters as an auxiliary or “reserve” thruster. The electron source of the at least one auxiliary thruster may be operated before creation of the ion stream to inject the electrons into the plasma surrounding the spacecraft.

Abstract: A satellite comprises a body and a generally planar structure extending from the body. One or more radio frequency “RF” antennas, an amplification system for RF signals, and a power distribution system for the amplification system are mounted on the generally planar structure. Two or all of the power distribution system, the one or more RF antennas and the amplification system are arranged on respective parallel boards (310, 312, 314) forming part of the generally planar structure (300). One or more of the parallel boards (310, 312, 314) and the components mounted thereon may be connected to another similar board to form, respectively, a larger power distribution system, antenna array or amplification system, for example arranged in a plurality of modules, each comprising at least one antenna, at least one power distribution system and at least one amplifier supported on at least two respective boards.