Patent classifications
B64G1/283
ENCLOSURES FOR FACILITATING ACTIVITIES IN SPACE, AND ASSOCIATED SYSTEMS AND METHODS
Enclosures for facilitating activities in space, and associated systems and methods, are disclosed. A representative system includes a spacecraft having an enclosed interior volume (which can be formed by an inflatable membrane) and one or more unmanned aerial vehicles (UAVs) carried by the spacecraft and positioned to deploy into the enclosed interior volume. The system can include a remote-control system to control the one or more UAVs from a terrestrial location while the spacecraft is in space. A wireless charging system can provide electrical power to the one or more UAVs. A representative method includes configuring one or more controllers to launch a first spacecraft to a first orbit, launch a second spacecraft to a second orbit, move the first spacecraft to the second orbit, dock the first spacecraft with the second spacecraft, and broadcast an event within an interior volume of the first spacecraft to a terrestrial location.
System and Method for Controlling a Motion of a Spacecraft in a Multi-Object Celestial System
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.
SMALL SCALE REACTION WHEEL ASSEMBLIES
Reaction wheel assemblies having relatively compact and lightweight form factors (referred to as “small scale” RWAs) are disclosed. Such small scale RWAs are well-suited for deployment onboard relatively small satellites, but are not restricted to usage within any particular device or platform. In one embodiment, the small scale RWA includes a primary support platform to which a rotor is coupled for rotation about a spin axis. An axially-expanded face-to-face (DF) duplex bearing pair is disposed between the rotor shaft and the support platform. The DF duplex bearing pair includes first and second rolling element bearings positioned around an intermediate portion of the rotor shaft. The first and second rolling element bearings have first and second bearing load lines, respectively, which are spaced by a tailored bearing load line separation (SLL).
AXIAL FLUX MOTOR
The present disclosure relates to an axial flux motor for a reaction wheel, and method of using and making the same. The motor includes a stator and a rotor. The stator comprises a printed circuit board (PCB) including a first motor coil. The rotor is coupled to a first ring-shaped magnet having an alternating pole arrangement. In a further embodiment, the rotor includes permanent magnets, and the stator PCB includes a first motor coil, and a first high thermal conductivity element.
APPARATUS AND METHODS FOR SPACECRAFT ATTITUDE CONTROL USING A SOLAR SAIL
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.
Rapid slew and settle systems for small satellites
A new approach for rapid slew and settle of small satellites is based on four single degree-of-freedom control moment gyroscopes with variable speed flywheels (or reaction wheels) in a pyramid configuration, combined with path and endpoint constraint time-optimal control. The path and endpoint constrained time-optimal control can be augmented with momentum management without the use of additional actuators.
Methods and apparatus for in-situ measurements of atmospheric density
A satellite in orbit around a planetary body includes a bus and a drag flap coupled to the bus. The drag flap is used to increase the drag torque applied to the satellite. The bus may house sensors and actuators, such as a star tracker, a gyroscope, a reaction wheel, and a global position system (GPS) receiver to monitor the attitude of the satellite in response to the applied drag torque. The measurements from the sensors and actuators may be used to determine the drag torque applied to the satellite. An estimate of the atmospheric density may be then be determined based on the drag torque. Compared to conventional approaches, the satellite and methods described herein estimates the atmospheric density at comparable, if not better, resolution and bandwidth. The atmospheric density estimates may also be acquired in real-time using a cheaper, lighter, and smaller satellite.
SPIN STABILIZATION OF A SPACECRAFT FOR AN ORBIT MANEUVER
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.
POWER-ENHANCED SLEW MANEUVERS
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.
METHODS FOR ATTITUDE CONTROL OF A SATELLITE IN SURVIVAL MODE WITHOUT A PRIORI KNOWLEDGE OF THE LOCAL TIME OF THE SATELLITE'S ORBIT
A method for attitude control of a satellite in inclined low orbit in survival mode is disclosed, the satellite including at least one solar generator, at least one solar sensor, magnetic torquers capable of forming internal magnetic moments in a satellite reference frame having three orthogonal axes X, Y, and Z, and inertial actuators capable of forming internal angular momentums in the satellite reference frame. The at least one solar sensor has a field of view at least 180° wide within the XZ plane around the Z axis, the method including a step of attitude control using a first control law, a step of searching for the sun by means of the at least one solar sensor, when a first phase of visibility of the sun is detected, and a step of attitude control using a second control law.