An electrospray thruster with integrated propellant storage directly embedded into small satellite structural elements integrates the volume of the thruster into the volume of the rail.

A system for positioning at least one satellite in working orbit, characterized in that the system for positioning satellites in working orbit comprises: a first attachment device configured to attach a first satellite to the system for positioning satellites in working orbit; a main propulsion device with solid propulsion comprising a plurality of parallel solid-propellant cartridges; a secondary propulsion device which is re-ignitable; at least one position sensor configured to measure the position of said system; a monitoring unit connected to said at least one position sensor and which is configured to control a firing of the cartridges of the main propulsion device to move said system from a transfer orbit to a working orbit of the first satellite, said monitoring unit being further configured to control an opening of the first attachment device to separate said system from the first satellite.

A method and system for activating thrusters of a vehicle for trajectory-tracking control of the vehicle. A transfer orbit generator to generate a transfer orbit for the vehicle from an initial orbit to a target orbit, and a feedback stabilization controller. Compute the target orbit for the vehicle about the celestial body. Compute a free trajectory with patch points along the free trajectory using a free trajectory module, each patch point includes a position and a velocity. Determine a feedback gain at each patch point using a feedback gain module, wherein a state penalty function at each patch point is set to match a state uncertainty function at the same patch point. Apply the feedback gain at each patch point to map the position and the velocity at each patch point to delta v commands, to maintain the target orbit using a feedback stabilization controller.

A monolithic attitude control motor frame includes a monolithic structure including an outer surface of revolution and a plurality of side walls defining a plurality of cavities extending radially from the outer surface of revolution. Adjacent cavities of the plurality of cavities share a side wall or side wall portion therebetween. Each of the cavities is configured to receive an attitude control motor. A monolithic attitude control motor system includes a monolithic frame including an outer surface of revolution and a plurality of side walls defining a plurality of cavities extending radially from the outer surface of revolution. The system further includes a plurality of attitude control motors corresponding to the plurality of cavities, such that an attitude control motor of the plurality of attitude control motors is disposed in each cavity of the plurality of cavities.

A monolithic attitude control motor frame includes a monolithic structure including an outer surface of revolution and a plurality of side walls defining a plurality of cavities extending radially from the outer surface of revolution. Adjacent cavities of the plurality of cavities share a side wall or side wall portion therebetween. Each of the cavities is configured to receive an attitude control motor. A monolithic attitude control motor system includes a monolithic frame including an outer surface of revolution and a plurality of side walls defining a plurality of cavities extending radially from the outer surface of revolution. The system further includes a plurality of attitude control motors corresponding to the plurality of cavities, such that an attitude control motor of the plurality of attitude control motors is disposed in each cavity of the plurality of cavities.

An on-orbit servicing spacecraft includes an engagement system to engage a space vehicle or object to be serviced or tugged, so as to form a space system, and an electronic reaction control system to cause the spacecraft to rotate about roll, yaw, and pitch axes to control attitude and displacement along given trajectories to cause the spacecraft to carry out given maneuvers. The electronic reaction control system includes (i) a sensory system to directly sense physical quantities or allow physical quantities to be indirectly computed based on sensed physical quantities, including one or more of position, attitude, angular rates, available fuel, geometrical features, and on-board systems state, (ii) attitude control thrusters mounted so as to allow their positions and orientations to be adjustable, and (iii) an attitude control computer in communication with the sensory system and the attitude control thrusters and programmed to receive data from the sensory system and to control, based on the received data, positions, orientations, and operating states of the attitude control thrusters so as to control attitude and position of the spacecraft. The attitude control computer is programmed to cause the spacecraft to carry out a given mission including an engagement step, in which the engagement system and the attitude control thrusters are controlled by the attitude control computer to engage a space vehicle or object to be serviced or tugged, and one or more operating steps, in each of which the attitude control thrusters are controlled by the attitude control computer to meet one or more requirements established for the operating step.

An on-orbit servicing spacecraft includes an engagement system to engage a space vehicle or object to be serviced or tugged, so as to form a space system, and an electronic reaction control system to cause the spacecraft to rotate about roll, yaw, and pitch axes to control attitude and displacement along given trajectories to cause the spacecraft to carry out given maneuvers. The electronic reaction control system includes (i) a sensory system to directly sense physical quantities or allow physical quantities to be indirectly computed based on sensed physical quantities, including one or more of position, attitude, angular rates, available fuel, geometrical features, and on-board systems state, (ii) attitude control thrusters mounted so as to allow their positions and orientations to be adjustable, and (iii) an attitude control computer in communication with the sensory system and the attitude control thrusters and programmed to receive data from the sensory system and to control, based on the received data, positions, orientations, and operating states of the attitude control thrusters so as to control attitude and position of the spacecraft. The attitude control computer is programmed to cause the spacecraft to carry out a given mission including an engagement step, in which the engagement system and the attitude control thrusters are controlled by the attitude control computer to engage a space vehicle or object to be serviced or tugged, and one or more operating steps, in each of which the attitude control thrusters are controlled by the attitude control computer to meet one or more requirements established for the operating step.

In an orbital attitude control device (1150), an ideal thrust axis direction calculator (1505) calculates an ideal thrust axis direction based on information of a predetermined orbit, an ideal attitude calculator (1506) calculates an ideal attitude of the satellite based on the ideal thrust axis direction and a solar direction, and a control torque calculator (1510) calculates an ideal control torque that makes the attitude of the satellite follow the ideal attitude and a torque restraint plane in which the solar direction is orthogonal to a rotational axis of the solar array panel, defines an evaluation function obtained by weighting a distance from the ideal control torque and a distance from the torque restraint plane and then summing the weighted distances, and calculates the control torque that allows the drive constraint to be satisfied and the evaluation function to be minimized.

In an orbital attitude control device (1150), an ideal thrust axis direction calculator (1505) calculates an ideal thrust axis direction based on information of a predetermined orbit, an ideal attitude calculator (1506) calculates an ideal attitude of the satellite based on the ideal thrust axis direction and a solar direction, and a control torque calculator (1510) calculates an ideal control torque that makes the attitude of the satellite follow the ideal attitude and a torque restraint plane in which the solar direction is orthogonal to a rotational axis of the solar array panel, defines an evaluation function obtained by weighting a distance from the ideal control torque and a distance from the torque restraint plane and then summing the weighted distances, and calculates the control torque that allows the drive constraint to be satisfied and the evaluation function to be minimized.

A reprovisionable spacecraft and reprovisioning subassemblies for mating with a reprovisionable spacecraft are both described. The reprovisionable spacecraft has one or more mechanical, thermal, data, and or electrical mating interfaces for attaching, powering, and communicating with a reprovisioning subassembly, which for one embodiment is a self-contained thruster unit. The self-contained thruster unit preferably comprises a fuel tank, control electronics, and a thruster assembly. Alternately, a reprovisioning subassembly can comprise a fuel tank and control electronics, a fuel tank, or a thruster. Also, a reprovisionable spacecraft may be carried into orbit without reprovisioning subassemblies attached, and then deployed after reprovisioning subassemblies have been attached to their respective mating interfaces. Reprovisioning utilizing a self-contained thruster unit or tank eliminates the large risk associated with refueling satellites in space. Reprovisioning also eliminates the need for a dedicated attached life extension vehicle.