A disclosed spacecraft is provided with: an attitude control actuator configured to control an attitude of the spacecraft; an imaging device configured to receive an optical communication signal from another spacecraft; and an attitude controller configured to control the attitude control actuator, based on a position of the optical communication signal in an image obtained by the imaging device.

To achieve an objective to enable a plurality of management business operators managing space objects flying in space, to share and carry out danger analysis efficiently. In a space traffic management system (500), a plurality of space traffic management devices (100) are connected to each other via a communication line. Each of the plurality of space traffic management devices includes a space information recorder (101), a danger alarm device (102), a danger analysis device (103), a danger avoidance action assist device (104), and a security device (105). The space information recorder includes a space object ID, orbital information, and public condition information; and a business device ID and public condition information. The plurality of space traffic management devices (100) have data format compatibility and share the space object ID and the business device ID, and share orbital information corresponding to the space object ID among business devices that comply with the public condition information.

Methods and apparatus to methods and apparatus for performing propulsion operations using electric propulsion system are disclosed. An example launch vehicle includes a first space vehicle including a first core structure and a first electric propulsion system, and a second space vehicle including a second core structure and a second electric propulsion system, the second core structure releasably attached to the first space vehicle in a stacked configuration.

A method for orbit control of a satellite in orbit around the Earth and for desaturation of an angular momentum storage device of satellite is disclosed having two articulated arms each supporting a propulsion unit. The method includes determining a maneuver plan having at least two thrust maneuvers, a first thrust maneuver to be executed using the propulsion unit of one of the articulated arms and a second thrust maneuver to be executed using the propulsion unit of the other articulated arm, controlling the articulated arms and the propulsion units according to the maneuver plan, at least one of the first and second thrust maneuvers being a thrust maneuver referred to as discontinuous, composed of at least two separate consecutive thrust sub-maneuvers.

A rotational negative-inertia converter (RNIC) has a housing enclosing a flywheel configured to rotate around an axis of symmetry; a motor with a stator attached to the housing and a rotor attached to the flywheel to rotate it around the axis of symmetry; a housing angular accelerometer attached to said housing; a flywheel angular accelerometer; and a controller configured to receive measured accelerometer values from the accelerometers. The controller is configured to drive the motor to maintain the angular acceleration of the flywheel at a value proportional to the housing angular acceleration, with a predetermined proportionality constant.

A method for calibrating an ADCS testbed comprising a DUT holder with three RNICs includes: using measured angular velocities of the DUT holder and RNIC flywheels, and ZGT data, to compute moments of inertia of the DUT holder with and without a satellite with ADCS, allowing compensation for those moments by the RNICs.

Cell-based systems may interlock in a reconfigurable configuration to support a mission. Space systems, for example, of a relatively large size may be assembled using an ensemble of individual “cells”, which are individual space vehicles. The cells may be held together via magnets, electromagnets, mechanical interlocks, etc. The topology or shape of the joined cells may be altered by cells hopping, rotating, or “rolling” along the joint ensemble. The cells may be multifunctional, mass producible units. Rotation of cell faces, or of components within cells, may change the functionality of the cell. The cell maybe collapsible for stowage or during launch.

In a distance control method of relative motion between satellites, by reducing the distance between a companion satellite and a reference satellite through the first position relation, and increasing the distance between a companion satellite and a reference satellite according to the second position relation, the distance between satellites can be kept between the set maximum distance and the minimum distance. In this way, on the one hand, the inter-satellite distance cannot be too large to ensure that the two satellites are within the maximum distance range required by communication or other cooperative relations. At the same time, the inter-satellite distance cannot be too small, and further avoid the collision between the two satellites. The method is capable of tolerating the effect of satellite orbit perturbation, allowing the inter-satellite distance to vary naturally between maximum and minimum distances, and thus saving control fuel consumption.

A method (50) for orbit control of a satellite (10) in Earth orbit and for desaturation of an angular momentum storage device of the satellite, the satellite (10) including an articulated arm (21) suitable for moving a propulsion unit (31) within a motion volume included in a half-space delimited by an orbital plane when the satellite is in a mission attitude, the method (50) including a single-arm control mode using only the propulsion unit (31) carried by the articulated arm (21), the single-arm control mode using a maneuvering plan including only thrust maneuvers to be executed when the satellite (10) is located within an angular range of at most 180° centered on a target node in the orbit of the satellite (10), including two thrust maneuvers to be performed respectively upstream and downstream of the target node.

A method for estimating collision between a satellite in orbit and at least one piece of space debris having a time of closest approach to the satellite is disclosed including: obtaining the reference orbit of the satellite; determining an ephemeris of state transition data representative of the trajectory of the reference orbit; communicating the reference orbit and the ephemeris of state transition data to the satellite. The method includes the steps on board the satellite of: determining the true orbital position of the satellite; propagating the true orbit; calculating a probability of collision between the satellite and the piece of debris.

A method for transferring a spacecraft (10), such as an artificial satellite, from an initial elliptical orbit (30) to a final geostationary orbit (50), the spacecraft taking at least one intermediate elliptical orbit (40) propelled by electric propulsion means (12, 13), the method includes: when the spacecraft is in an intermediate orbit, a nominal thrust step (410) in which the propulsion means generate nominal thrust while the spacecraft is on at least part of a first orbital arc (41) passing through the apogee A of the intermediate orbit, and a minimum thrust step (420), in which the propulsion means are partly stopped or slowed while the spacecraft is on at least part (43) of a second orbital arc (42) passing through the perigee P of the intermediate orbit, the two orbital arcs being complementary.