Abstract: A satellite having a longitudinally elongated body and being capable of operating in the thermosphere. The satellite can be powered by an electric rocket engine, and includes a remote sensing system configured to obtain images of Earth. An elongated axis about which the elongated body extends can be generally aligned with a forward direction of the satellite, with a viewing angle from the satellite oriented transverse to the elongated axis. A center of mass of the satellite can be forward of a center of drag to produce positive natural stability. The remote sensing system, which can be part of a payload, can include a movable mirror and one or more movable optical elements. A first mirror can be pivoted, and/or other optical elements, including the payload, can be rotated about the axis of the elongated body. Counter-acting masses can be used to null motion of the movable components.

Abstract: A satellite having a cooling system to remove heat from an electric rocket engine using a working fluid. The cooling system can include a pump that circulates working fluid along a cooling loop between the rocket engine and a radiator. The cooling system can also utilize thermoacoustic, Stirling refrigeration, and/or heat pipe techniques. One or more reservoirs can be provided to store the working fluid, and in some forms a secondary reservoir can be provided to aid in management of a center of mass of the satellite. A fluid reaction loop can be provided in which working fluid is accelerated to impart a torque on the satellite. In some forms, the working fluid can be utilized as both a coolant and a propellant for the rocket engine. The electric rocket thruster can also include one or more internal pathways for the conveyance of working fluid.

Abstract: The present disclosure relates generally to thrust vector control mechanisms. Mechanisms are provided comprising support and attachment members for securing a thruster or other object to an additional object and wherein the thruster or object is provided with freedom of movement. At least one motor is provided to control movement and positioning of a thruster or similar object.

Abstract: The present disclosure relates generally to thrust vector control mechanisms. Mechanisms are provided comprising support and attachment members for securing a thruster or other object to an additional object and wherein the thruster or object is provided with freedom of movement. At least one motor is provided to control movement and positioning of a thruster or similar object.

Abstract: An autonomous method for minimizing the magnitude of plasma discharge current oscillations in a Hall effect plasma device includes iteratively measuring plasma discharge current oscillations of the plasma device and iteratively adjusting the magnet current delivered to the plasma device in response to measured plasma discharge current oscillations to reduce the magnitude of the plasma discharge current oscillations.

Abstract: An autonomous method for minimizing the magnitude of plasma discharge current oscillations in a Hall effect plasma device includes iteratively measuring plasma discharge current oscillations of the plasma device and iteratively adjusting the magnet current delivered to the plasma device in response to measured plasma discharge current oscillations to reduce the magnitude of the plasma discharge current oscillations.