Patent classifications
B64G1/283
Modular and configurable attitude control system for a spacecraft
A spacecraft attitude control module (1) according to the invention is compact and easy to assemble with additional modules to form an operative attitude control system. The module comprises a robust rectangular, preferably cubic support frame with an attitude control assembly fitted within the confines of the support frame, the assembly including a reference structure comprising a platform, a flywheel support structure (15, 18, 19, 26) and a flywheel (25). The flywheel support structure may be fixed to the platform (10) or it may be a gimbal structure that is rotatable relative to the platform. In the first case the module is a reaction wheel module. In the second case the module is a single gimbal control moment gyroscope module. A preferred embodiment includes a slanted position of the platform (10) relative to the ground plane (100) of the support frame. Another preferred characteristic is the implementation of a flywheel provided with a hollow portion (25) into which the motor (28) that is driving the flywheel rotation is fitted. The invention is also related to an attitude control system comprising multiple modules assembled together on a support plate (35). The modules may be provided with decking plates (39, 39) to improve the mechanical robustness of the assembly and to realize fast electrical connections to the modules.
ARTIFICIAL SATELLITE AND THRUST BALANCE ADJUSTMENT METHOD
A reaction wheel detects an angular momentum. A satellite controller selects a target thruster based on the detected angular momentum. A power supply apparatus changes adjustment electric power for the target thruster. A flow rate adjustment apparatus supplies a propellant to the target thruster at a flow rate corresponding to the adjustment electric power. This changes a thrust of the target thruster. When a discharge current of the target thruster does not become a target current, the power supply apparatus further changes the adjustment electric power for the target thruster.
Sphere magnetic levitation system and method of operating sphere magnetic levitation system
Provided is a sphere magnetic levitation system having magnetic-aligning devices that magnetically align the position of a sphere levitated by electromagnets according to whether the sphere is levitated, and a method of operating the sphere magnetic levitation system. The sphere magnetic levitation system includes: a sphere; a plurality of electromagnets symmetrically positioned about the sphere and spaced apart from the sphere at equal distances; and a plurality of magnetic-aligning devices provided around the sphere, and coming into contact with the sphere or separated from the sphere by a predetermined distance according to the modes of the system. The system is operated in one mode from among: an idle mode, in which the magnetic-aligning devices are in direct contact with and support the sphere; and an operation mode, in which the magnetic-aligning devices are separated from the sphere and the sphere is levitated and rotated.
Method and system for controlling the orbit of a satellite in earth orbit
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.
Enclosures for facilitating activities in space, and associated systems and methods
Enclosures for facilitating activities in space, and associated systems and methods, are disclosed. A representative system includes a spacecraft having an enclosed interior volume (which can be formed by an inflatable membrane) and one or more unmanned aerial vehicles (UAVs) carried by the spacecraft and positioned to deploy into the enclosed interior volume. The system can include a remote-control system to control the one or more UAVs from a terrestrial location while the spacecraft is in space. A wireless charging system can provide electrical power to the one or more UAVs. A representative method includes configuring one or more controllers to launch a first spacecraft to a first orbit, launch a second spacecraft to a second orbit, move the first spacecraft to the second orbit, dock the first spacecraft with the second spacecraft, and broadcast an event within an interior volume of the first spacecraft to a terrestrial location.
ENERGY EFFICIENT SATELLITE MANEUVERING
Energy efficient satellite maneuvering is described herein. One disclosed example method includes maneuvering a satellite that is in an orbit around a space body so that a principle sensitive axis of the satellite is oriented to an orbit frame plane to reduce gravity gradient torques acting upon the satellite. The orbit frame plane is based on an orbit frame vector.
ENCLOSURES FOR FACILITATING ACTIVITIES IN SPACE, AND ASSOCIATED SYSTEMS AND METHODS
Enclosures for facilitating activities in space, and associated systems and methods, are disclosed. A representative system includes a spacecraft having an enclosed interior volume (which can be formed by an inflatable membrane) and one or more unmanned aerial vehicles (UAVs) carried by the spacecraft and positioned to deploy into the enclosed interior volume. The system can include a remote-control system to control the one or more UAVs from a terrestrial location while the spacecraft is in space. A wireless charging system can provide electrical power to the one or more UAVs. A representative method includes configuring one or more controllers to launch a first spacecraft to a first orbit, launch a second spacecraft to a second orbit, move the first spacecraft to the second orbit, dock the first spacecraft with the second spacecraft, and broadcast an event within an interior volume of the first spacecraft to a terrestrial location.
Attitude determination using earth horizon sensors
Described herein are systems and methods for attitude determination using infrared Earth horizon sensors (EHSs) with Gaussian response characteristics. Attitude information is acquired by detecting Earth's infrared electromagnetic radiation and, subsequently, determining the region obscured by Earth in the sensors' fields of view to compute a nadir vector estimation in the spacecraft's body frame. The method can be applied when two sensors, each with known and distinct pointing directions, detect the horizon, which is defined as having their fields of view partially obscured by Earth. The method can be implemented compactly to provide high-accuracy attitude within small spacecraft, such as CubeSat-based satellites.
ARTIFICIAL SATELLITE AND METHOD OF CONTROLLING THE SAME
Provided are an artificial satellite and a method of controlling the same. The artificial satellite includes a main body flying along an orbit of a planet, an optical payload arranged on the main body to photograph a ground surface of the planet, and a pair of solar cell panels rotatably arranged on both sides of the main body in a first direction, wherein the first direction and a flight direction of the main body form an acute angle with each other.
MODEL PREDICTIVE CONTROL OF SPACECRAFT
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.