A spacecraft has a flat antenna array having an edge and a middle portion. A reconfigurable reaction-momentum wheel is coupled to the antenna array to roll and/or pitch the antenna array in small magnitudes. The reconfigurable reaction-momentum has a reaction operating state or mode (high-torque, low momentum) and a momentum operating state or mode (low-torque, high momentum). A thruster is coupled to the antenna array to move the antenna array.

A spacecraft for changing an orbit or an attitude of a target in outer space by irradiating the target with a laser, the spacecraft includes: a laser apparatus configured to generate the laser; a focusing unit configured to converge the laser; a detecting unit configured to acquire detection information including a distance between the spacecraft and the target; and an irradiation control unit configured to control the focusing unit on the basis of the distance so that the laser converges on the target.

For power-enhanced slew maneuvers, a method determines a power collection function for a satellite. The method determines a power cost function for the satellite. The method calculates a power enhanced slew maneuver based on the power collection function and the power cost function.

A launch lock system includes a first portion rigidly coupled to the second portion in a first state and the first portion movable in all directions relative to the second portion in a second state. The launch lock system includes a fastener subassembly coupled to the second portion, and the fastener subassembly is movable relative to the second portion from a first position to a second position. The launch lock system includes at least one pivot arm subassembly having a pivot arm movable between a first position and a second position. The pivot arm is coupled to the first portion in the first position. In the first state, the pivot arm is in the first position and cooperates with the fastener subassembly in the first position, and in the second state, the pivot arm is uncoupled from the first portion and the fastener subassembly.

A method of roll steering of a spacecraft to align an aspect of the spacecraft, such as the surface of solar arrays carried by the spacecraft, to the sun, is described. The roll steering occurs only when the sun is at an angle (β) relative to the orbital plane of the spacecraft and when the spacecraft is not eclipsed by a body it is orbiting. This dayside-only roll steering of the spacecraft increases the power efficiency of the spacecraft. A spacecraft may include a controller which causes an attitude control subsystem to steer the spacecraft about a roll axis to position the surface of the solar array such that an axis normal to the surface of the solar array is aligned with the direction to a sun when the sun is visible to the spacecraft, and maintain a fixed orientation of the spacecraft about the roll axis when the sun is not visible to the spacecraft.

The disclosure relates to a method and apparatus of rotating mass attitude control. The method and apparatus entails rotating a mass to generate thrust. Varying the speed and direction of rotation provides some control of the magnitude and direction of the thrust generated. The method and apparatus of the invention pertinent to an attitude control system for spacecrafts or astromotive vehicles under conditions of zero to low gravity and atmosphere.

An attitude control module is described for providing propellant-free attitude control and momentum desaturation to a spacecraft. The attitude control module includes at least one solar sail comprising a reflective surface for reflecting solar photons; and at least one robotic arm coupled to the at least one solar sail, said at least one robotic arm comprising at least 4 degrees of freedom for positioning and orienting the at least one solar sail relative to the spacecraft. A corresponding method for operating the attitude control module to unload excess momentum from a spacecraft is also described.

A system for optimizing a low-thrust trajectory of a spacecraft trajectory for orbital transfer includes an interface to receive data, a memory to store scheduled geostationary transfer orbit (GTO) data and scheduled geostationary Earth orbit (GEO) data and computer-executable programs, and a processor. The processor is configured to provide a two-dimensional (2D) averaged trajectory consisting of a predetermined revolutions by executing the optimal control program using the GTO data and GEO data, arrange N equidistant points on the 2D averaged trajectory to form segments on the 2D averaged trajectory, obtain osculating elements corresponding to the segments by solving optimization problems for the segments, estimate initial guesses of the segments under continuous thrusting conditions in tangential directions at the N equidistant points, solve a minimum energy optimization problem to obtain a minimum energy 2D osculating trajectory by using as initial guess the concatenation of segments, compute a minimum energy three-dimensional (3D) osculating trajectory by linearly decreasing an inclination of the minimum energy 2D osculating trajectory to zero, and generating a minimum fuel 3D osculating trajectory by iteratively solving a cost function while changing a parameter from one to zero.

A free-floating spherical gimbal (“gimbal”) that includes a moving portion substantially spherical in shape and partially enclosed within a larger spherical and stationary cavity. The moving portion of the spherical gimbal is maintained in a location without direct mechanical contact with the stationary cavity.

A spacecraft capable of generating an artificial gravity environment comprises frame with a circular track with at least two modules traveling on the track. The two modules are configured to engage the first track opposite the first module to minimize mass imbalance, and a balancing system for the first and second modules configured to mass balance the first and second modules relative to each other. The frame itself does not rotate, and may have other mission supporting structures attached, including storage and supply modules, and observational modules, and spacecraft hangars and spacecraft docking modules. A method of operating a spacecraft to generate artificial gravity in a habitation module comprises operating a frame in space, propelling first and second habitation modules about the frame to generate artificial gravity environments in the modules, and mass balancing the first module relative to the second module to maintain balance of the spacecraft.