To provide a sheet-like structure capable of highly accurately estimating a sheet-like shape. A sheet-like structure includes a sheet-like member and a plurality of detection sensors. The sheet-like member extends along an in-plane direction orthogonal to a thickness direction and receives light incident on the sheet-like member. The plurality of detection sensors are dispersedly arranged on the sheet-like member along the in-plane direction and are for detecting an incident angle of the light with respect to the sheet-like member at each arrangement position of the plurality of detection sensors.

[Object] To provide a sheet-like structure capable of highly accurately estimating a sheet-like shape.

[Solving Means] A sheet-like structure includes a sheet-like member and a plurality of detection sensors. The sheet-like member extends along an in-plane direction orthogonal to a thickness direction and receives light incident on the sheet-like member. The plurality of detection sensors are dispersedly arranged on the sheet-like member along the in-plane direction and are for detecting an incident angle of the light with respect to the sheet-like member at each arrangement position of the plurality of detection sensors.

Apparatus and methods for controlling a spacecraft for a transfer orbit. The spacecraft includes a momentum subsystem that stores angular momentum relative to a center of mass of the spacecraft, and a propulsion subsystem that includes electric thrusters. A controller identifies a target spin axis for the spacecraft, determines gimbal angles for electric thruster(s) that so that thrust forces from the electric thrusters are parallel to the target spin axis, and initiates a burn of the electric thruster(s) at the gimbal angles. The controller controls the momentum subsystem to compensate for a thruster torque produced by the burn of the electric thrusters. The momentum subsystem is able to produce a target angular momentum about the center of mass, where a coupling between the target angular momentum and an angular velocity of the spacecraft creates an offset torque to counteract the thruster torque.

Apparatus and methods for controlling a spacecraft for a transfer orbit. The spacecraft includes a propulsion subsystem with electric thrusters that are installed with two-axis gimbal assemblies. The spacecraft also includes a controller that identifies a target spin axis for the spacecraft, determines an actual spin axis for the spacecraft during the transfer orbit, determines gimbal angles for the electric thruster(s) that adjust the actual spin axis toward the target spin axis, and initiates a burn of the electric thruster(s) at the gimbal angles.

Described herein are systems and methods for attitude determination using infrared Earth horizon sensors (EHSs) with Gaussian response characteristics. Attitude information is acquired by detecting Earth's infrared electromagnetic radiation and, subsequently, determining the region obscured by Earth in the sensors' fields of view to compute a nadir vector estimation in the spacecraft's body frame. The method can be applied when two sensors, each with known and distinct pointing directions, detect the horizon, which is defined as having their fields of view partially obscured by Earth. The method can be implemented compactly to provide high-accuracy attitude within small spacecraft, such as CubeSat-based satellites.

A refinery spacecraft comprises a hub section defining a longitudinal axis, an excavator segment to convey material into the hub section, first, second and third rotary ring segments rotatable about the hub section with adjustable speed and direction, each rotary ring segments comprising three modules configured to carry out refining or storage processes and wherein two of the three modules in each rotary ring segment have adjustable angular positions relative to the longitudinal axis. Methods of collecting and refining substances from an asteroid, derelict orbiting spacecraft or other space junk, can comprise attaching a refining spacecraft to an asteroid, extracting material from the asteroid, transferring material into a refining hub, transferring material to refining rings orbiting the refining hub, and controlling orbiting of the refining rings about the hub to establish and maintain angular momentum of the refining spacecraft at a stable condition.

[Object] To provide a sheet-like structure capable of highly accurately estimating a sheet-like shape. [Solving Means] A sheet-like structure includes a sheet-like member and a plurality of detection sensors. The sheet-like member extends along an in-plane direction orthogonal to a thickness direction and receives light incident on the sheet-like member. The plurality of detection sensors are dispersedly arranged on the sheet-like member along the in-plane direction and are for detecting an incident angle of the light with respect to the sheet-like member at each arrangement position of the plurality of detection sensors.

A control system for reducing disturbance torque of a spacecraft is disclosed. The spacecraft revolves around a celestial body surrounded by an atmosphere. The control system includes processors in electronic communication with one or more actuators and a memory. The memory stores data into a database and program code that, when executed by the one or more processors, causes the control system to instruct the spacecraft to enter a safing mode. In response to entering the safing mode, the control system instructs the one or more actuators to align a principal axis of the spacecraft with a vector that is normal to the orbit around the celestial body. The control system also instructs the actuators to rotate the spacecraft about the principal axis, where a rotational orientation of the spacecraft relative to the celestial body is shifted by about one-half a rotation about the principal axis.

Technologies for guidance of a spin-stabilized orbital rocket are described herein. The spin-stabilized rocket includes a guidance controller. The guidance controller computes parameters of a burn of a second-stage engine of the rocket to reach a desired nominal orbit subsequent to burnout of the first stage of the rocket. The guidance controller computes the burn parameters of the second-stage engine based upon one or more desired orbit parameters and a current position and velocity of the rocket. The computation of the burn parameters is based upon a simulated point-mass model of the motion of the rocket. The guidance controller then controls the rocket to initiate a second-stage burn having the computed burn parameters.

A control system for reducing disturbance torque of a spacecraft is disclosed. The spacecraft revolves around a celestial body surrounded by an atmosphere. The control system includes processors in electronic communication with one or more actuators and a memory. The memory stores data into a database and program code that, when executed by the one or more processors, causes the control system to instruct the spacecraft to enter a safing mode. In response to entering the safing mode, the control system instructs the one or more actuators to align a principal axis of the spacecraft with a vector that is normal to the orbit around the celestial body. The control system also instructs the actuators to rotate the spacecraft about the principal axis, where a rotational orientation of the spacecraft relative to the celestial body is shifted by about one-half a rotation about the principal axis.