A space vehicle system, a method of manufacturing a multiple space vehicle launch system, and a method to transmit a launch load between space vehicles during a launch are disclosed. The space vehicle system may include a first space vehicle including a first core structure, a second space vehicle including a second core structure releasably attached to the first space vehicle in a stacked configuration, a first solar array supported by the first core structure, the first core structure extending beyond a lower edge of the first solar array, and a second solar array supported by the second core structure, the second core structure extending beyond an upper edge of the second solar array.

Micro-emitter arrays and methods of microfabricating such emitter arrays are provided. The microfabricated emitter arrays incorporate a plurality of emitters with heights greater than 280 microns with uniformity of +/?10 microns arranged on a supporting silicon substrate, each emitter comprising an elongated body extending from the top surface of the substrate and incorporating at least one emitter tip on the distal end of the elongated body thereof. The emitters may be disposed on the substrate in an ordered array in an X by Y grid pattern, wherein X and Y can be any number greater than zero. The micro-emitter arrays may utilize a LMIS propellant source including, for example, gallium, indium, bismuth, or tin. The substrate may incorporate at least one through-via providing a fluid pathway for the LMIS propellant to flow from a propellant reservoir beneath the substrate to the top substrate surface whereupon the micro-emitter array is disposed.

A satellite propellant tank includes a tank body and a dome attached to the tank body to enclose an interior volume for propellant storage. One or more cavities are formed in the dome. One or more propellant control components are located in the one or more cavities formed in the dome.

A space vehicle engine (10) comprising a chemical thruster having a nozzle (30) for ejecting combustion gas, together with a Hall effect thruster. The engine is arranged in such a manner that the nozzle serves as the ejection channel for particles ejected by the Hall effect thruster when it is in operation. The engine can deliver high thrust with low specific impulse or relatively low thrust with large specific impulse.

A method that is stored in tangible form and accessible by a data processing system for determination of xenon propellant remaining in a tank for a defined life condition. A heater controller establishes a first stable temperature of a propellant tank. A measurement is performed of a temperature and a pressure at the first stable temperature of the propellant tank. A second higher stable temperature is provided in the propellant tank. A measurement is performed of a temperature and a pressure at a second stable temperature. A computer processor computes a mass based on density and volume in accordance with measurements of temperature and pressure at the first stable temperature and the second stable temperature.

A control algorithm that determines one or more deviations in an orbit of a companion satellite, and control the companion satellite to minimize effects of perturbing forces.

A pointing mechanism for use in an electric propulsion system of a spacecraft, the pointing mechanism comprises a mobile plate adapted to receive a thruster and defining a thrust vector of the thruster received on the mobile plate. The pointing mechanism further comprises a rotary actuator coupled to the mobile plate by means of a connecting element, the rotary actuator being configured to rotate the connecting element about a rotational axis of the rotary actuator such that the thrust vector defined by the mobile plate rotates about the rotational axis, wherein the thrust vector is inclined relative to the rotational axis.

A satellite system operates at altitudes between 100 and 350 km relying on vehicles including a self-sustaining ion engine to counteract atmospheric drag to maintain near-constant orbit dynamics. The system operates at altitudes that are substantially lower than traditional satellites, reducing size, weight and cost of the vehicles and their constituent subsystems such as optical imagers, radars, and radio links. The system can include a large number of lower cost, mass, and altitude vehicles, enabling revisit times substantially shorter than previous satellite systems. The vehicles spend their orbit at low altitude, high atmospheric density conditions that have heretofore been virtually impossible to consider for stable orbits. Short revisit times at low altitudes enable near-real time imaging at high resolution and low cost. At such altitudes, the system has no impact on space junk issues of traditional LEO orbits, and is self-cleaning in that space junk or disabled craft will de-orbit.

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.

A spacecraft is disclosed including a frame, an electrical device powered and/or controlled by electrical cables, and a system for orienting the electrical device, which orientation system includes at least two rotary actuators with non-parallel axes (a, b), a junction part between the two rotary actuators, one or more guide forks, arranged outside the junction part and fastened to the latter, each guide fork including fingers configured to support the electrical cables and to form a guide path for said cables so that the electrical cables never exert, on the rotary actuators, a torque higher than the torque capacity of the actuators, at least one of the forks having a main axis which passes through the center of intersection of the axes of rotation of the actuators.