Conductive cooled gimbaled inertial measurement units are disclosed herein. An example apparatus includes an inertial measurement unit, a gimbal assembly in which the inertial measurement unit is disposed, the gimbal assembly having gaps between each gimbal of the gimbal assembly, the gaps including a gas to conduct heat from the gimbal assembly, and an isothermal dome at least partially surrounding the gimbal assembly, the isothermal dome having a cooling tube disposed on an external surface of the isothermal dome to transfer heat from the gimbal assembly via conduction.

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. In another embodiment, the system provides the crewmember with a directional cue (e.g., a visual, auditory, or tactile cue) 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.

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.

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 system, method, and computer-readable storage devices for a 6U CubeSat with a magnetometer boom. The example 6U CubeSat can include an on-board computing device connected to an electrical power system, wherein the electrical power system receives power from at least one of a battery and at least one solar panel, a first fluxgate sensor attached to an extendable boom, a release mechanism for extending the extendable boom, at least one second fluxgate sensor fixed within the satellite, an ion neutral mass spectrometer, and a relativistic electron/proton telescope. The on-board computing device can receive data from the first fluxgate sensor, the at least one second fluxgate sensor, the ion neutral mass spectrometer, and the relativistic electron/proton telescope via the bus, and can then process the data via an algorithm to deduce a geophysical signal.

Embodiments described herein provide for passive timing of asynchronous Inertial Measurement Unit (IMU) attitude data using information derived from a pattern of skipped and duplicate samples of attitude data generated by the IMU. One embodiment is an attitude controller for a vehicle that generates samples of attitude data at a first frequency (f1) from an IMU of the vehicle. The IMU updates the attitude data at a second frequency (f2). Each update of the attitude data includes a time stamp. The attitude controller is processes time stamps in the samples to identify a pattern of at least one of a skipped sample of an update to the attitude data and a duplicate sample of an update to the attitude data. The attitude controller estimates lag times between updates of the attitude data and samples of the attitude data based on the pattern and a relationship between f1 and f2.

A control system for a satellite comprises a power source and control system, a propulsion system having individually selectable solid fuel motors, a communication interface and an attitude determination and control system (ADCS). The ADCS receives power from the power source and control system and further receives desired orbital or positional instructions via the communication interface. Based on the desired orbital or position instructions, the ADCS generates and provides commands to the propulsion system. In turn, the propulsion system selects and fires one or more motors of the individually selectable solid fuel motors responsive to the commands received from the ADCS. A satellite may comprise the disclosed satellite control system as well as attitude control components and/or sensor components operatively connected to the satellite control system.

Systems and methods can support a plasma propulsion system. The system may include a thrust head comprising a plasma generator and a thrust generator. A propellant handling assembly may be directly coupled to the thrust head. The propellant handling assembly may comprise a manifold and a plurality of valves. A propellant storage vessel may be directly coupled to the propellant handling assembly. A propulsion control module may be operable to receive inputs associated with the plasma propulsion system, generate control outputs associated with the plasma propulsion system, establish and train models relating the inputs and the control outputs, apply the inputs to the models to update the output parameters, and apply the output parameters to control the plasma propulsion system.

The invention relates to a system and method for autonomous navigation of a host satellite equipped with moving and orienting means, a unit for controlling these means, and at least one on-board image-acquisition camera, said method comprising the following steps: acquiring (E1) a plurality of images; default processing of said images, referred to as long-range processing (E2), configured to detect and identify space objects and to calculate their relative orbits; conditional processing of said acquired images, referred to as short-range processing (E3), configured to estimate the attitude of at least one of said space objects, referred to as target object, detected during the long-range processing, this step being implemented when said long-range step detects at least one space object located at a distance estimated to be less than a predetermined threshold distance; determining (E4) a possible rendezvous between at least said target object and the host satellite; preparing and transmitting instructions (E5) to said control unit of said moving means based on at least one rendezvous and/or risk of collision determined in the previous step.

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.