A gimbal system includes a stationary base with a first motor being coupled thereto. A rotation plate is coupled to the first motor for rotation in a plane opposing the stationary base when the first motor is operated. A tilt plate is hingedly coupled to the rotation plate along a tilt axis. An articulating arm is coupled to the tilt plate. A second motor is fixedly mounted to the rotation plate for rotation therewith. The second motor is coupled to the articulating arm such that the articulating arm causes the tilt plate to rotate through a tilt angle about the tilt axis and relative to the rotation plate when the second motor is operated.

A method for controlling the orbit of a satellite in earth orbit. The orbit of the satellite is controlled by commanding, according to a maneuver plan, a propulsion system having at least one thruster and a transporter to move the propulsion system. The maneuver plan includes at least two orbit-control maneuvers. The thrust powers of the propulsion system during the two orbit control maneuvers have respective thrust directions that are not parallel in an inertial frame of reference. Each thrust power is determined to simultaneously control the inclination and the position of the orbit of the satellite as well as to form a momentum that is suitable for unloading a device for storing angular momentum of the satellite in a plane orthogonal to the direction of thrust of the thrust power.

A spacecraft including a set of thrusters for changing a pose of the spacecraft. At least two thrusters mounted on a gimbaled boom assembly and are coupled together sharing the same gimbal angle. A model predictive controller (MPC) to produce a solution for controlling thrusters of the spacecraft by optimizing a cost function over a receding horizon using a model of dynamics of the spacecraft effecting a pose of the spacecraft and a model of dynamics of momentum exchange devices of the spacecraft effecting an orientation of the spacecraft. A modulator to modulate magnitudes of the thrust of the coupled thrusters determined by the MPC as pulse signals specifying ON and OFF states of each of the coupled thruster, wherein the ON states of the coupled thrusters sharing the same gimbal angle do not intersect in time. A thruster controller to operate the thrusters according to their corresponding pulse signals.

An operation of a spacecraft is controlled using an inner-loop control determining first control inputs for momentum exchange devices to control an orientation of the spacecraft and an outer-loop control determining second control inputs for thrusters of the spacecraft to concurrently control a pose of the spacecraft and a momentum stored by the momentum exchange devices of the spacecraft. The outer-loop control determines the second control inputs using a model of dynamics of the spacecraft including dynamics of the inner-loop control, such that the outer-loop control accounts for effects of actuation of the momentum exchange devices according to the first control inputs determined by the inner-loop control. The thrusters and the momentum exchange devices are controlled according to at least a portion of the first and the second control inputs.

Methods and apparatus to methods and apparatus for performing propulsion operations using electric propulsion system are disclosed. An example apparatus includes means to use an electric propulsion system coupled to a frame of a spacecraft, the electric propulsion system including at least a first thruster and a second thruster, the first thruster adjacent a first side of the frame, the second thruster adjacent a second side of the frame, and means to allow at least one of the first thruster or the second thruster to control the spacecraft without using a chemical propulsion system.

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.

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 service satellite for providing station keeping services to a host satellite has a body, and a gripping mechanism attached to the body. The gripping mechanism is adapted to attach to an interface ring extending from an external surface of the host satellite to form an interconnection between the host satellite and the service satellite through the externally extending interface ring. Attaching the gripping mechanism to the interface ring forms an interconnected unit having a combined center of mass. The service satellite has at least two movable thrusters and at least one controller. The at least one controller maintains the interconnected unit in a substantially stationary orbit by selectively orienting the two thrusters such that the thrust vectors from the two thrusters do not pass through the combined center of mass, and are each offset from the combined center of mass.

A device for holding and aligning a component includes a first and a second housing part and a tilting device. The first housing part is arranged on a first end for stationary arrangement on a carrier and the second housing part is arranged on a second end for connection to the useful component. The first end and the second end are on opposite sides of the device in relation to a longitudinal axis. The tilting device mechanically connects the first and the second housing parts to one another and enables a defined alignment and holding of the relative position of the second housing part in relation to the first housing part. The actuator of the tilting device is a number of wires made of a shape-memory alloy. A length of each of the number of wires is individually adjustable by a respective determination of the resistance, which can be processed as a control variable in a control loop.

Apparatus and methods for stationkeeping in a satellite. The satellite includes a north electric thruster and a south electric installed on a zenith side, an east chemical thruster installed on an east side, and a west chemical thruster installed on a west side. An orbit controller detects a failure of one of the electric thrusters. In response to the failure, the orbit controller controls a burn of the remaining electric thruster proximate to an orbital node. The orbit controller controls a burn of one of the chemical thrusters at 90??5? from the burn of the remaining electric thruster, and controls a burn of the other one of the chemical thrusters at 270??5? from the burn of the remaining electric thruster.