Abstract:
Satellite systems and methods to perform rendezvous and docking between a servicer satellite and an on-orbit satellite, and specifically to satellite systems and methods to perform rendezvous and docking between a servicer satellite and an on-orbit client satellite using electric propulsion thrusters. In one aspect, a servicer satellite with a set of thruster arms each attached to an electric propulsion thruster performs acceleration, deceleration, and steering maneuvers through six degree of freedom positioning of the thrusters, the same set of thruster arms and thrusters performing station keeping of the docked servicer-client satellite system.
Abstract:
Disclosed is a metaverse platform operating method and system for implementing a virtual universe space. The metaverse platform operating method includes: obtaining a plurality of satellite data from a satellite vehicle on a predetermined period for a predetermined time; constructing space situational awareness (SSA) information associated with the satellite vehicle by processing the plurality of satellite data; generating a metaverse-based virtual universe space in which the satellite vehicle is positioned for the predetermined time, through three-dimensional (3D) modeling of the SSA information; at an access request from a device, identifying a satellite-related organization to which the device belongs, using a login account included in the access request; and visualizing the metaverse-based virtual universe space on the device according to an information access right of the satellite-related organization.
Abstract:
A reaction wheel apparatus including a reaction wheel provided in a polyhedral housing, in which respective faces constituting a polyhedron are constituted by frame parts corresponding to the respective faces constituting the polyhedron, and at least two of the frame parts are constituted by at least two rigid circuit board parts of a rigid flexible substrate.
Abstract:
A method for providing thermal balance of spacecraft electronics is provided. The spacecraft includes two or more electronic units wherein each electronic unit is capable of performing the same spacecraft operational task. The method for balancing the temperature of spacecraft electronics further includes providing each of the two or more electronic units with a temperature sensor for determining the temperature of that electronics unit. The electronic units and their respective temperature sensors are connected to a controller. In the event that the controller determines that the temperature of an activated first electronics unit has reached or exceeded a predetermined threshold, and the controller has determined that the temperature of a second deactivated electronics unit is below a predetermined threshold, the controller automatically deactivates the first electronics unit and activates the second electronics unit to perform the task previously being performed by the first electronics unit. This process continues automatically.
Abstract:
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.
Abstract:
A method of controlling the attitude of a spacecraft in spinning around itself with a non-zero total angular momentum HTOT. The spacecraft includes a set of inertia flywheels configured to form an internal angular momentum HACT. The axis of the total angular momentum HTOT is aligned with a principal axis of inertia of the spacecraft, in the course of which the inertia flywheels are controlled to form an internal angular momentum HACT. The following expression, in which J is the inertia matrix of the spacecraft: Hact×J−1(HtotJ−1Htot) is negative if the principal axis of inertia targeted is the axis of maximum inertia of the spacecraft and is positive if the principal axis inertia targeted is the axis of minimum inertia of the spacecraft.
Abstract:
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.
Abstract:
An orbit transfer method for a spacecraft using a continuous or quasi-continuous thrust propulsion, the method comprises: the acquisition, at least once in each half-revolution of the spacecraft, of measurements of its position and of its velocity; the computation of a thrust control function as a function of the measurements; and the driving of the thrust in accordance with the control law; wherein the control law is obtained from a Control-Lyapunov function using orbital parameters, preferably equinoctial, of the spacecraft, averaged over at least one half-revolution. An embedded driving system for a spacecraft for implementing such a method and a spacecraft equipped with the driving system are provided.
Abstract:
Systems and method of attitude determination and control for spacecraft include the use of a unified set of sensors for all phases of space flight. For example, the same set of sensors may be used for on-station operations and transfer orbit operations. The use of a unified set of sensors reduces complexity, spacecraft cost, and spacecraft weight.
Abstract:
In order to control the attitude of a satellite having at least four gyroscopic actuators with respective spinners mounted on gimbals steerable about axes parallel to one or the other of only two different directions that are fixed relative to the satellite, the attitude of the satellite is measured using sensors on board the satellite, the control torque required to perform an attitude-changing maneuver is calculated, local linearization calculation is performed based on pseudo-inversion of the Jacobean matrix of the function associating the orientations of the actuator gimbals with the total kinetic moment of the cluster in order to determine a new gimbal orientation, and precession speeds of at least one of the gimbals of the actuators is controlled to deliver the control torque for reaching the desired configuration. The calculation is performed while applying a constraint of seeking a cluster configuration that is remote from singular configurations by sharing between the two groups of actuators that component of the total kinetic moment of the cluster which is perpendicular to both of the two directions.