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.

When the number of CMGs is represented by n (n is an integer of 4 or more), (n3) gimbal angles out of n gimbal angles corresponding to the n CMGs are set as free parameters, and an algebraic equation representing a relationship among three gimbal angles out of the n gimbal angles, the free parameters, and an angular momentum of all the CMGs is used to solve the algebraic equation while changing the free parameters within set ranges, to thereby obtain solutions of the gimbal angles of the plurality of CMGs required for achieving a given angular momentum.

Provided is an apparatus for controlling an orbiting satellite by sensing a change in a yaw angle of the orbiting satellite and calculating a ground sample distance (GSD) based on the yaw angle. The apparatus may include a sensor configured to sense a yaw angle corresponding to yaw steering of the orbiting satellite, and a processor configured to calculate, based on the yaw angle, a GSD corresponding to a length of a pixel projected onto a planetary surface scanned by the orbiting satellite.

A method and apparatus for estimating gyro scale factor during normal spacecraft operations, using small attitude motions that are compliant with mission pointing accuracy and stability requirements and a signal processing method that specifically detects the intentionally induced motions. This process increases operational availability by avoiding the need to take the spacecraft offline for large calibration maneuvers.

A space-based solar power station, a power generating satellite module and/or a method for collecting solar radiation and transmitting power generated using electrical current produced therefrom is provided. Each solar power station includes a plurality of satellite modules. The plurality of satellite modules each include a plurality of modular power generation tiles including a photovoltaic solar radiation collector, a power transmitter and associated control electronics. The power transmitters can be coordinated as a phased array and the power generated by the phased array is transmitted to one or more power receivers to achieve remote wireless power generation and delivery. Each satellite module may be formed of a compactable structure capable of reducing the payload area required to deliver the satellite module to an orbital formation within the space-based solar power station.

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.

A menu-type design method based on optimized information fusion applied to a GEO satellite control system is provided, which includes: configuring four long-life inertial attitude sensor gyroscopes for a long-life GEO satellite control system; configuring sensors capable of measuring three-axis attitude according to a menu-type design requirement on hardware, where the long-life inertial attitude sensor gyroscopes and the sensors capable of measuring three-axis attitude are combined to form three types of Kalman filters; autonomously sorting, by the satellite-borne computer application software, the Kalman filters; and in a case where an FDIR module detects a fault, autonomously generating, by the FDIR module, an alarm corresponding to the fault, and autonomously performing, by a currently selected Kalman filter, reduced-order filtering, and in a case where the fault is not eliminated within a set time period, issuing, by the FDIR module, a macro instruction sequence to perform autonomous reorganization.

A system and method for assisted EVA self-return is provided herein. The system estimates a crewmember's navigation state relative to a fixed location, for example on an accompanying orbiting spacecraft, and computes a guidance trajectory for returning the crewmember to that fixed location. The system may account for safety and clearance requirements while computing the guidance trajectory. According to at least one embodiment, the system actuates the crewmember's safety jetpack to follow the prescribed trajectory to the fixed location.

A system and method for assisted EVA self-return is provided herein. The system estimates a crewmember's navigation state relative to a fixed location, for example on an accompanying orbiting spacecraft, and computes a guidance trajectory for returning the crewmember to that fixed location. The system may account for safety and clearance requirements while computing the guidance trajectory. According to at least one embodiment, the system provides a directional cue (e.g., a visual, auditory, or tactile cue) to a crewmember corresponding to the prescribed trajectory back to the fixed location. The system may be activated by the crewmember or remotely by another crewmember and/or system.

A method and apparatus for estimating gyro scale factor during normal spacecraft operations, using small attitude motions that are compliant with mission pointing accuracy and stability requirements and a signal processing method that specifically detects the intentionally induced motions. This process increases operational availability by avoiding the need to take the spacecraft offline for large calibration maneuvers.