Abstract: In drive circuitry for powering an arc jet or ion engine aboard a spacecraft carrying solar panels, a start-up circuit interconnects an array of series-parallel connected solar panels to establish and maintain an arc and plasma in the engine. In the start-up circuit, an electric switch is placed in parallel with an electrode assembly of the engine. One terminal of the engine connects directly with the solar panel array, and another terminal of the engine connects via an inductor to the solar panel array. A capacitor connects across terminals of the solar panel array. A series connection of solar panels increases the voltage from that which is available from a single panel. Conduction of current from the solar panel via the inductor is initiated by the switch to store magnetic energy within the conductor. Thereupon, upon an opening of the switch, the inductor produces a relatively high voltage which strikes an arc in the engine.

Abstract: A spacecraft for deployment in geosynchronous orbit about the Earth, comprising six face panels which enclose a compartment containing electronic powering components mounted on the interior surfaces thereof. The panels include opposed north-facing and south-facing panels which do not undergo sun-exposure, remain cool and provide safe interior surfaces for the electronic powering components mounted thereon, and four side panels which are successively rotated into diurnal sun-exposure attitude during which their temperature normally rises so excessively as to damage electronic powering components mounted on the interior surfaces thereof. The invention comprises providing the east-facing and west-facing panels with at least one continuous circulation system containing a heat exchange fluid which absorbs heat from the one of said panels undergoing sun exposure and circulates it to the other of said panels to moderate the temperature of the east-facing and west-facing panels.

Abstract: A three-axis stabilized spacecraft having roll, pitch, and yaw axes and when on station in orbit about the earth having a north face and a south face is equipped with a first and second thruster which may be electric thrusters. A first support device mounts the first thruster adjacent the north face and the first thruster is positioned a spaced distance away from the north face in a first direction parallel to the pitch axis and spaced from the pitch axis in a second direction normal to the pitch axis. A second support device mounts the second thruster adjacent the south face, the second thruster being positioned a spaced distance away from the south face in a third direction opposite the first direction and spaced from the pitch axis in the second direction. A gimbal mechanism pivotally mounts the first and second thrusters on the first and second support devices, respectively, for selectively positioning the attitude of the first and second thrusters.

Abstract: In drive circuitry for powering an arc jet or ion engine aboard a spacecraft carrying solar panels, a start-up circuit interconnects an array of series-parallel connected solar panels to establish and maintain an arc and plasma in the engine. In the start-up circuit, an electric switch is placed in parallel with an electrode assembly of the engine. One terminal of the engine connects directly with the solar panel array, and another terminal of the engine connects via an inductor to the solar panel array. A capacitor connects across terminals of the solar panel array. A series connection of solar panels increases the voltage from that which is available from a single panel. Conduction of current from the solar panel via the inductor is initiated by the switch to store magnetic energy within the conductor. Thereupon, upon an opening of the switch, the inductor produces a relatively high voltage which strikes an arc in the engine.