The present disclosure provides a method for controlling orbital trajectories of a plurality of spacecraft in a multi-spacecraft swarm. In one aspect, the method includes deploying a DRL agent including a plurality of trajectory control models to the multi-spacecraft swarm, the trajectory control models corresponding to swarm configurations of the multi-spacecraft swarm; determining a state vector of said plurality of spacecraft in the multi-spacecraft swarm; transmitting a collective command to the multi-spacecraft swarm, such that said plurality of spacecraft in the multi-spacecraft swarm are to be distributed in one of the swarm configurations; determining actions of said plurality of spacecraft based on the state vector and the collective command; and maneuvering the multi-spacecraft swarm in accordance with the actions.

A method for capturing and deorbiting space debris includes: providing a space debris capturing device; deploying the space debris capturing device in planetary orbit; determining, via an onboard global positioning system unit, the position and orbit velocity of the space debris capturing device; receiving an initial target set including a first database of space debris targets that are within range of the space debris capturing device; performing a first algorithm to convert the initial target set to an accessible target set including a second database of space debris targets that are within range of the space debris capturing device, the second database is smaller than the first database; performing a second algorithm to convert the accessible target set to a final target set including a third database of space debris targets to be captured by the space debris capturing device, the third database is smaller than the second database; transferring the space debris capturing device to a position within a capture range of a first space debris target of the third database; capturing the first space debris target via a capture mechanism of the space debris capturing device; jettisoning the capture mechanism and the first captured space debris target into a decaying orbit; repeating the transferring, capturing, and jettisoning steps for all but a final one of the remaining space debris targets of the third database; and positioning the space debris capturing device and the final captured space debris target into a decaying orbit.

A spacecraft including: an engine; a thrust vector control device controlling a thrust vector as a direction of a thrust acting on the spacecraft; and a main control device configured to acquire state quantities of the spacecraft in a powered descending in which the spacecraft is guided to a target point while the engine generates the thrust, and generate a throttling command by which combustion of the engine is controlled and an operation command by which the thrust vector control device is operated. The state quantities contain a first acceleration parameter and a second acceleration parameter. The first and second acceleration parameters are calculated as coefficients A and B obtained by fitting based on acceleration of the spacecraft previously detected, supposing the following equation is satisfied between a reciprocal number 1/a of the acceleration a of the spacecraft and time t:
1/a=−At+B  (1).

A method of communication with a non-GEO constellation of satellites, includes providing an Earth-based terminal configured for communication with a satellite constellation, and establishing communication between the Earth-based terminal and a non-GEO constellation of satellites, the non-GEO constellation of satellites including a first plurality of satellites orbiting at a first inclination, wherein each of the satellites in the first plurality of satellites is in a discrete planar orbit to form a first snake of satellites, the first snake of satellites including adjacent satellites in adjacent orbits having adjacent RAAN (Right Ascension of the Ascending Node), wherein the Earth-based terminal is positioned and configured for continuous communication with at least one satellite from the non-GEO constellation of satellites.

A method for attitude control of a satellite in inclined low orbit in survival mode is disclosed, the satellite including at least one solar generator, at least one solar sensor, magnetic torquers capable of forming internal magnetic moments in a satellite reference frame having three orthogonal axes X, Y, and Z, and inertial actuators capable of forming internal angular momentums in the satellite reference frame. The at least one solar sensor has a field of view at least 180° wide within the XZ plane around the Z axis, the method including a step of attitude control using a first control law, a step of searching for the sun by means of the at least one solar sensor, when a first phase of visibility of the sun is detected, and a step of attitude control using a second control law.

Provided is a configuration construction and attitude control method for a pyramid deorbit sail. By taking into consideration environmental perturbation like atmospheric resistance perturbation and non-spherical earth perturbation, a dynamics model featuring three-dimensional orbit-and-attitude coupling based on position vectors and quaternion descriptions, the deorbit sail is taken as a rigid body, a spacecraft body is taken as a mass point, airflow obstruction is considered in the windward area, thereby improving the precision of the dynamics model; based on this model, the law of influence of the configuration parameters in the deorbit sail, such as a cone angle and a strut length, on the attitude stability and deorbiting efficiency of the spacecraft in different cases is analyzed, the configuration parameters of the pyramid deorbit sail system are analyzed and optimized according to the derived law, so as to obtain a pyramid deorbit sail achieving high attitude stability and high deorbiting efficiency.

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 satellite comprises thrusters disposed with the firing directions each facing away from the mass center of satellite and different from each other. A control amount calculator calculates control amounts of the mean orbital elements from the mean orbital elements and the temporal change rates of the mean orbital elements set by an orbit determiner, and the target values. A distributor calculates firing timings and firing amounts of the thrusters for realizing the control amounts of the mean orbital elements by expressing a motion of satellite with orbital elements, solving an equation taking into account coupling of an out-of-plane motion and an in-plane motion due to thruster disposition angles and thruster firing amounts at multiple times, and combining one or more thruster firings controlling mainly an out-of-the-orbit-plane direction and one or more thruster firings controlling mainly an in-the-orbit-plane direction.

Methods, systems and computer readable media are presented for computing a guidance control policy to transition an uncertain dynamical system from an initial state to a final state, in which a set of points are computed to provide discreet and accurate representation of uncertainty, and in which a guidance control policy is computed based on a set of equations involving the initial state, the final state, state variables, control variables, and parameters, as well as designated parameters of interest, a set of constraints corresponding to state and control variables, a performance metric, statistical distribution types corresponding to the parameters of interest, statistical moments individually corresponding to the parameters of interest, and weighting values corresponding to the parameters of interest. A guidance control policy which defines control variables for transitioning from the initial state to the final state which is robust to the considered system uncertainty is computed according to the computed set of points and the performance metric.

A method of controlling a satellite and a computer-readable recording medium are provided. The method is for controlling a satellite moving along an orbit having an inclination angle from the equatorial plane to capture due-north images. The method includes: determining a position of the satellite; calculating a roll angle and a pitch angle of the satellite for pointing a line-of-sight vector of the satellite to a first ground surface being a photographing point; determining a compensation angle by considering effects of the inclination angle and rotation of the Earth so as to capture images in the due north direction of the photographing point; calculating a yaw angle based on the compensation angle; and rotating the satellite according to the calculated roll angle, pitch angle, and yaw angle.