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 apparatus for designing, constructing and using instrument landers for in situ exploration of small solar system bodies, such as asteroids and comets. In one aspect, a lander includes a CubeSat-style platform; instrument packaging, wherein the CubeSat-style platform and the instrument packaging are configured and arranged for an uncontrolled descent, hopping landing on a surface of a body in a solar system, where a descending trajectory for the lander is designed based on gravitational force and solar radiation, with no lander-based propulsion; and a mobility mechanism configured and arranged to self-orient the lander on the surface of the body in the solar system.

A robotic platform for traversing and manipulating a modular 3D lattice structure is described. The robot is designed specifically for its tasks within a structured environment, and is simplified in terms of its numbers of degrees of freedom (DOF). This allows for simpler controls and a reduction of mass and cost. Designing the robot relative to the environment in which it operates results in a specific type of robot called a “relative robot”. Depending on the task and environment, there can be a number of relative robots. This invention describes a bipedal robot which can locomote across a periodic lattice structure made of building block parts. The robot is able to handle, manipulate, and transport these blocks when there is more than one robot. Based on a general inchworm design, the robot has added functionality while retaining minimal complexity, and can perform numerous maneuvers for increased speed, reach, and placement.

Systems and methods for pointing photovoltaic arrays for optimal power generation. One or more methods among a plurality of methods for pointing an array may be used by a spacecraft control system to point the array. Example methods to use to point the photovoltaic array relate to analyzing current output, analyzing image data, and analyzing computational knowledge of reflective bodies or light sources. The spacecraft may be further controlled to reduce shadow by re-orienting, receiving light reflected off spacecraft, and orienting a photovoltaic array relative to incoming light sources based on topographic properties of the array such as cell grooves.

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.

To provide a sheet-like optical device capable of selectively emitting light whose optical path has a changed orientation. An optical device includes a first sheet and a second sheet. The first sheet is configured to be electrically switchable between a first state in which the first sheet extends along an in-plane direction orthogonal to a thickness direction and has transparency in the thickness direction, and a second state in which the first sheet has lower transparency in the thickness direction than the transparency in the first state. The second sheet has a prism surface on which an inclined surface inclined with respect to the in-plane direction is arranged along the in-plane direction, the second sheet facing the first sheet in the thickness direction.

A method and system for satellite control in space using an IP-based satellite bus and all-IP compliant subsystems and payload(s) and a corresponding T&C system. Specifically, the present method/system includes a satellite-based IP Bus (connected as a network) that relies on Ethernet, USB, WIFI, or Bluetooth to connect various satellite components, satellite components configured to communicate on the IP bus, and a T&C system that understands the IP bus and can read its telemetry and commands. The system permits operations control on-orbit, in near real time within a secure system environment, with a dramatic increase in mission efficiency, an expansion of how much and what can be done on-orbit, and cost savings on future missions using IP-compliant spacecraft and payloads.

Various implementations of an extinguishable, solid propellant divert system for a flight vehicle are disclosed. Also disclosed are methods for using the divert system to control the flight of a flight vehicle. In one implementation, a divert system includes a hot gas generator pneumatically linked to one or more divert thrusters and an extinguishment valve. The extinguishment valve can be opened to rapidly depressurize the hot gas generator and extinguish the solid propellant burning inside. In another implementation, a method of controlling the trajectory of the flight vehicle includes repeatedly igniting and extinguishing the solid propellant in a hot gas generator and using the hot gas to provide divert thrust for the flight vehicle.

The present disclosure provides a system and a method for controlling a motion of a spacecraft in a multi-object celestial system while avoiding an unauthorized entry into a keep-away region during a normal and an abnormal operation of the spacecraft. The method includes executing, during the normal operation of the spacecraft, a nominal control law subject to constraints on maintaining a state of the spacecraft within a union of a plurality of control invariant sets of values of the state of the spacecraft. The state of the spacecraft includes a location of the spacecraft and at least one or a combination of a velocity and an acceleration of the spacecraft. The method further includes executing, upon detecting the abnormal operation of the spacecraft, an abort control law associated with the control invariant set including a current state of the spacecraft.

An attitude control system includes one or more control moment gyro pairs, with gyros of individual of the pairs being counter-rotated to rotate the rotation axes of flywheels of the gyros of a gyro pair in opposite direction. The flywheels of a gyro pair may be in paddle configuration, with the rotation axes of the flywheels rotating in the counter-rotation through separate planes as the gyros are rotated. The rotation of the gyros of a gyro pair may be accomplished by coupling both of the gyros to a servo motor with suitable coupling gears, or by using independent servos for each gyro. The counter-rotation of gyros of an individual pair produces a resultant torque about a fixed global axis, such as the axis of a flight vehicle of which the attitude control system is a part. Further control may be accomplished for example by varying rotation speeds of the flywheels.