In an example embodiment, an attitude, orbit, and de-orbit control system (AODCS) for a satellite is provided. In an example embodiment, the AODCS system comprises one or more selectively retractable booms. The one or more selectively retractable booms are collectively configured to provide a selectively adjustable drag during de-orbiting of a satellite over a predefined de-orbiting time.

Provided is a single-axis pointing pure magnetic control algorithm for a spacecraft based on geometrical analysis to realize single-axis pointing control of the spacecraft through the pure magnetic control algorithm in which a magnetic torque is only output by a magnetorquer to interact with a geomagnetic field to generate a control torque. The algorithm uses a spatial geometry method to obtain an optimally controlled magnetic torque direction, thereby designing a PD controller. The problem that the traditional magnetic control method is low in efficiency and even cannot be controlled is overcome. The algorithm is simple and easy, can be used in the attitude control field of spacecrafts, and achieves the pointing control in point-to-sun of a solar array and point-to-ground of antennae.

Provided are an earth satellite attitude data fusion system and method, applicable to an earth satellite space environment to estimate attitude data of a satellite. When the earth satellite attitude data fusion system of the present invention is used to perform the earth satellite attitude data fusion method, the first step is to perform a body rates/quaternion attitude data processing operation. Then, the next step is to perform an attitude/rates data fusion processing operation, wherein an attitude data fusion algorithm module receives a first IAE result data from a first EKF, and a second IAE result data from a second EKF, and performs an attitude/rates data fusion algorithm in a subsystem level to evaluate an attitude estimation IAE performance based on the first IAE result data, and the second IAE result data.

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.

The invention relates to small satellites capable to fly in formation (10), in particular nano- or picosatellites with a mass of 10 kg or less, for LEO applications, comprising a housing (12) and at least one plug-in board (14) arranged in the housing (12) with a predetermined functionality and a propulsion system (16) for generating a directed pulse in the direction of the flight trajectory T.sub.k. It is proposed that the small satellite (10) comprises an independent and autonomously working collision avoidance system (18), which is capable of adapting a trajectory correction T.sub.kk of the trajectory T.sub.k by the propulsion system (16), when a collision with an object (30) is expected. In a further independent aspect, the invention relates to a formation (100) composed of several small satellites capable to fly in formation (10), wherein a relative position and flight trajectory T.sub.k of each small satellite (10) is modifiable via the independently and autonomously working collision avoidance system (18).

An attitude control apparatus (20) includes an ideal thrust direction calculator (22), an ideal attitude calculator (24), a target attitude calculator (26), and a torque calculator (28). The ideal thrust direction calculator (22) calculates an ideal thrust direction of a thruster. The target attitude calculator (26) calculates a target attitude that is the attitude of a satellite in which a deviation from an ideal attitude is minimized within a movement limitation of an attitude control actuator (14) while a panel surface faces the sun. The torque calculator (28) calculates a torque for turning the satellite from an actual attitude to the target attitude and transmits a torque instruction to the attitude control actuator (14).

A control system for a momentum wheel device is specified, wherein the momentum wheel device is a real momentum wheel device (1) and has a momentum wheel which is driven by a motor, and wherein a simulated momentum wheel device (2) is provided which simulates the behaviour of an ideal momentum wheel on the basis of an ideal physical model (12). The rotational speed of both the real momentum wheel device (1) and of the simulated momentum wheel device (2) can be changed by a torque command (6). A comparator device (11) is provided for comparing the real rotational angle (9) of the real momentum wheel device (1) and the simulated rotational angle (14) of the simulated momentum wheel device (2) and for generating a fault signal (15) corresponding to a deviation between the real rotational angle (9) and the simulated rotational angle (14). The fault signal (15) can be conducted to a control device (3), in order to actuate the motor on the basis of the fault signal (15), for the purpose of reducing the deviation.

A satellite attitude data fusion system and method is disclosed, applicable to the earth satellite environment to estimate attitude data of the satellite. When the satellite attitude data fusion system of the present invention is used to perform the satellite attitude data fusion method, the first step is to perform a body rates quaternion attitude data processing operation. Then, the next step is to perform an attitude/rates data fusion processing operation, wherein an attitude data fusion algorithm module receives the first IAE result data from the first EKF, and the second JAE result data from the second EKF, and performs an attitude/rates data fusion algorithm in a subsystem level to evaluate an attitude estimation JAE performance.

A system detects a maneuver of at least one space object by receiving a first data set relating to orbital characteristics of at least one space debris object. The system trains a model, using the first data set, in order to model orbital behaviors of the at least one space debris object. The system then receives a second data set relating to orbital characteristics of the at least one space object, and detects a maneuver of the at least one space object using the trained model and the second data set.

A dual solution candidate searcher receives an input of information about a constraint coefficient matrix and a cost vector, determines a dual problem of a linear programming problem being a primal problem and all active sets representing combinations of active formulas in constraints of the dual problem, finds, for each of the active sets, a feasible dual solution candidate meeting constraints, and stores the dual solution candidate into a storage in a manner associated with a corresponding one of the active sets. An optimal solution calculation device receives an input of a constraint vector as, selects an optimal one of the active sets as an optimal active set based on an inner product of the constraint vector and the dual solution candidate stored in the storage, and finds and outputs a basic feasible solution corresponding to the selected active set as an optimal solution.