A first spacecraft and a second spacecraft are configured to be disposed together, in a launch configuration, for launch by a single launch vehicle. In the launch configuration, the first spacecraft is mechanically coupled with a primary payload adapter of the launch vehicle, and the second spacecraft is mechanically coupled with the first spacecraft by way of an inter-spacecraft coupling arrangement. The spacecraft are configured to be deployed, following injection into a first orbit by the launch vehicle, by separating the first spacecraft from the primary payload adapter while the second spacecraft is mechanically coupled with the first spacecraft. A first onboard propulsion subsystem of the first spacecraft includes one or more thrusters configured to execute an orbit transfer maneuver from the first orbit to a second orbit. A propellant line arrangement detachably couples the first onboard propulsion subsystem with a second propellant storage arrangement on the second spacecraft.

Apparatus and methods for controlling a spacecraft for a transfer orbit. The spacecraft includes a propulsion subsystem with electric thrusters that are installed with two-axis gimbal assemblies. The spacecraft also includes a controller that identifies a target spin axis for the spacecraft, determines an actual spin axis for the spacecraft during the transfer orbit, determines gimbal angles for the electric thruster(s) that adjust the actual spin axis toward the target spin axis, and initiates a burn of the electric thruster(s) at the gimbal angles.

Disclosed is a satellite which includes: at least one optical photography instrument including a main lens having an optical axis and the optical instrument having a field of view; at least one launcher interface system, intended for being removably secured to a satellite interface system of a launcher of the satellite; a linking device between the launcher interface and the optical instrument extending substantially parallel to the optical axis of the main lens between an upper end and a lower end; the launcher interface system is connected to the linking device by the lower end and the optical axis of the optical instrument is directed from the upper end towards the lower end of the linking device, the launcher interface system being outside the field of view of the instrument.

A propulsion system for an orbiting vehicle such as a low-Earth orbit (LEO) satellite includes a set of surfaces over which a gas passes during orbital flight, and a plurality of electrodes on the surfaces. The electrodes are configured to create an electric field having a spatial field pattern in response to field signals, experienced by passing gas molecules as an oscillating field having a frequency on the order of a polarization-resonance frequency of the molecules to impart a propulsive traveling-wave dielectrophoretic force to the passing molecules. The electrodes extend over sufficient area to impart sufficient traveling-wave dielectrophoretic force to the gas to overcome aerodynamic drag and thereby sustain orbital flight of the vehicle. A power source applies the field signals to the electrodes, providing sufficient power to overcome power lost to aerodynamic drag and thereby sustain orbital flight.

A spacecraft includes a spacecraft main body, including payload equipment disposed on an inner panel surface of at least one radiator panel, the at least one radiator panel having an exterior-facing outer panel surface. The spacecraft includes at least one electric thruster disposed proximate to an aft facing panel of the spacecraft main body. The at least one electric thruster is thermally coupled with the at least one radiator panel by way of a thermally conductive path.

A propulsion system includes at least one group of electric thrusters that are spatially distributed in a multi-axis system. A controller is in communication with each of the electric thrusters. The controller is configured to differentially throttle the thrusts of the electric thrusters with respect to propulsion force about two axes of the multi-axis system.

A circuit for igniting and sustaining an electron discharge includes an ignitor circuit. The ignitor circuit includes a high voltage transformer and a switch connected in series between a primary of the transformer and a DC source return. The switch is configured to receive a driving signal. A reset circuit is connected in parallel to the primary of the high voltage transformer. A first rectifier is connected in series between a secondary of the high voltage transformer and a keeper. A terminal of the secondary of transformer is connected to a cathode. The circuit for igniting and sustaining the electron discharge also includes a sustaining circuit having a current source with a return connected to a cathode and a second rectifier connected in series between the current source and the keeper.

In an example, a method includes interacting electric fields from charges in conductors in different inertial reference frames to effect motion. The example method implements the mathematical framework that divides electric fields from charges in different inertial reference frames into separate electric field equations in electrically isolated conductors. The example method may implement the interaction of these electric fields to produce a force on an assembly that can, by way of illustration, propel a spacecraft using electricity without other propellant(s).

Systems and methods are described herein for mounting a thruster onto a vehicle. A thruster mounting structure may comprise a first, second, and third rotational joint, a boom, and thruster pallet, and a thruster attached to the thruster pallet. The first rotational joint may be attached to the vehicle and configured to rotate in a first axis. The first rotational joint may be connected to the boom and configured to pivot the boom about the first axis. The boom may be connected to the second rotational joint, which is connected to the third rotational joint and configured to rotate the third rotational joint in the first axis. The third rotational joint may be connected to the thruster pallet and configured to pivot the thruster pallet in a second axis that is perpendicular to the first axis.

The use of an accelerometer for inertial navigation of a low thrust spacecraft undergoing acceleration wherein the inaccuracy of the accelerometer is less than the uncertainty in the accuracy of a modeled non-gravitational component of the acceleration that the spacecraft is undergoing is disclosed. A method of navigating a spacecraft having a low thrust propulsion system is also disclosed. The method comprises engaging the low thrust propulsion system, measuring the acceleration of the spacecraft using an accelerometer with an inaccuracy less than the uncertainty in the acceleration imparted by the low thrust propulsion system and acquiring a trajectory estimate using the measured acceleration. The trajectory estimate may be updated using an external reference navigation sensor.