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.

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.

Disclosed is a method for designing a reentry trajectory based on flight path angle planning, including the following steps: S1. extracting an actual operating parameter of an aircraft, setting a maximum dynamic pressure n.sub.max a maximum stagnation point heat flux {dot over (Q)}.sub.max, and a maximum overload n.sub.max according to a mission requirement, and solving for a velocity-height boundary of a reentry trajectory; S2. solving for a reentry trajectory in an initial descent stage according to differential equations of reentry motion, and setting up a flight-path-angle lower limit .sub.min(V) according to the reentry trajectory in the initial descent stage, the velocity-height boundary, and a target point in a velocity-height phase plane; and S3. planning, based on the flight-path-angle lower limit .sub.min(V), a flight path angle satisfying terminal constraints, and calculating a corresponding bank angle to obtain a reentry trajectory.

A lunar orbiting satellite system executes orbit planning of assigning a function (positioning, communication, and flashing) to an artificial satellite (AS) depending on a relative position of the AS to the moon at a time when the moon and the AS are observed from an input point on the earth, and correcting the relative position, which changes in accordance with the moon revolution period. The system includes: a satellite orbit planner which assigns a function to each ASs forming an AS group flying around the moon depending on a relative position of each ASs to the moon at a time when the moon and ASs are observed from an input point on the earth, and set a target orbit according to the function; and a satellite controller which causes the each ASs to execute control based on the function to implement switching of the function.

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.

An attitude control system for a satellite is presented that can determine on time values for attitude control thrusters without use of attitude rate sensors, such as those based on gyros. The attitude control systems uses the attitude values from a star tracker to determine both attitude adjustment values and attitude adjustment rate values directly from the star tracker values, where the processing is performed using quaternions. From the attitude adjustment values and attitude adjustment rate values, a set of thruster on time values are determined.

The present invention relates to an aerospace vehicle navigation and control system comprising a terrestrial illumination matching module for determining spacecraft position and attitude. The method permits aerospace vehicle position and attitude determinations using terrestrial lights using an Earth-pointing camera without the need of a dedicated sensor to track stars, the sun, or the horizon. Thus, a module for making such determinations can easily and inexpensively be made onboard an aerospace vehicle if an Earth-pointing sensor, such as a camera, is present.

A controller controls a spacecraft to rendezvous a non-center-of-mass point of the controlled spacecraft with a non-center-of-mass point of an uncontrolled celestial body. The controlled spacecraft and the uncontrolled celestial body form a multi-object celestial system, and the controller produces control commands to thrusters of the controlled spacecraft using a non-linear model predictive control (NMPC) optimizing a cost function over a receding horizon that minimizes an error between coordinates of the non-center-of-mass point of the spacecraft and the non-center-of-mass point of the celestial body subject to joint dynamics of the multi-object celestial system coupled with joint kinematics of the multi-object celestial system.

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.

Techniques for performing spacecraft rendezvous and/or docking include operating a first orbiting spacecraft, the first spacecraft including a sensor arrangement, a first processor and a first inter-satellite link (ISL) arrangement and performing one or both of a rendezvous operation and a docking operation with the first spacecraft and a second orbiting spacecraft, the second spacecraft including one or more actuators. The performing one or both of the rendezvous operation and the docking operation includes determining a pose and pose rate of the second spacecraft relative to the first spacecraft using observations made by the sensor arrangement and determining a desired approach trajectory for the second spacecraft.