A magnetic levitation reaction sphere includes a spherical-housing-shaped rotor and three groups of stators. Each group includes two stators using the sphere center of the rotor as a symcenter. Axes of the three groups are mutually orthogonal. Each stator comprises a stator core and a coil array. An air gap is reserved between an inner surface of each stator core and the outer surface of the rotor. Through grooves are radially formed in the stator cores. The coil arrays are disc-type motor stator windings. Two effective sides of each coil in each coil array are respectively placed in two through grooves of the corresponding stator core. The magnetic levitation reaction sphere has low cost; levitation and rotation driving are integrated; the magnetic levitation reaction sphere has a simple and compact structure, a small size and a low mass, and relates to inherent stable levitation; and the levitation control is simple.

A stackable pancake satellite that is configured so that a plurality of the satellites can be stacked within a payload fairing of a launch vehicle. Each satellite includes sections that are folded or rotated together prior to launch, and unfolded or rotated away from each other when deployed. A first section is a satellite body having a first side that acts as a thermal radiator and a second side opposite the first side that includes an antenna. A second section includes one or more solar panels attached adjacent to the first side of the satellite body. A third section includes a splash plate reflector attached adjacent to the second side of the satellite body that reflects signals between Earth and the antenna. When deployed, the solar panels are pointed towards the Sun and the splash plate reflector directs the signals between the Earth and the antenna.

An attitude control apparatus for a satellite includes: at least three electric motors, wherein the at least three electric motors are arranged in such a way that a torque may be generated with any orientation of an associated torque vector, and a controller, wherein the controller is configured to drive the at least three electric motors based on a torque controller. The torque controller is adapted to operate the at least three electric motors outside a rest state only when an acceleration torque and a braking torque are required to execute an agile attitude change maneuver. There is also described an associated method.

A satellite configuration includes a plurality of individual satellite buses each having a number of side panels that form a polygonal shape, where the individual satellite buses collectively fit together to form the satellite configuration having a regular polygon shape. A method of producing the satellite configuration includes forming a plurality of individual satellite buses each having a polygonal shape, and fitting the individual satellite buses together to form the satellite configuration in a regular polygonal shape.

A reaction wheel apparatus including a reaction wheel provided in a polyhedral housing, in which respective faces constituting a polyhedron are constituted by frame parts corresponding to the respective faces constituting the polyhedron, and at least two of the frame parts are constituted by at least two rigid circuit board parts of a rigid flexible substrate.

Provided is a reaction wheel assembly ruggedized for use in kinetically launched satellites. An example reaction wheel assembly may include a shaft mounted to a body of a satellite, a wheel mounted to the shaft, wherein a center of a gravity of the wheel is co-aligned with the shaft, and a support device mounted to the body of the satellite. The reaction wheel assembly may include bearings for holding the shaft to the body of the satellite and allowing a rotation of the wheel. The support device can be engaged to support the wheel to reduce a load on the shaft and the bearing, the load being caused by an acceleration of the satellite during a kinetic launch of the satellite. After the satellite is launched into space, the support device can be disengaged from supporting the wheel to allow the wheel to spin.

Embodiments of Reaction Wheel Assembly (RWA) systems are provided, which include multi-faceted bracket structures to which RWAs are mounted. In one embodiment, the RWA system includes a bracket structure, which is assembled from multiple (e.g., two to four) interchangeable panels. Each bracket panel may define or include a mount bracket to which an RWA is mounted. In certain embodiments, the bracket panels may include integral bearing cartridge features, which contain the spin bearings of the RWAs. The interchangeable panels may have interconnect features, which align and which possibly interlock to position the panels in a precise angular relationship when the multi-faceted bracket structure is assembled. In other embodiments wherein the bracket structure is assembled from two interchangeable panels or produced as a single piece, the multi-faceted bracket structure may have a peaked form factor supportive of two RWAs, which are mounted to the bracket structure in a back-to-back relationship.

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.

A spacecraft including a spacecraft bus and a set of thrusters for changing a pose of the spacecraft. Wherein at least two thrusters are mounted on a gimbaled boom assembly connecting the two thrusters with the spacecraft bus, such that the two thrusters are coupled thrusters sharing the same gimbal angle. A model predictive controller to produce a solution for controlling thrusters of the spacecraft by optimizing a cost function over multiple receding horizons. The cost function is composed of a cost accumulated over the multiple receding horizons, including a cost accumulated over a first horizon using a dynamics governing a north-south position of the spacecraft, and a cost accumulated over a second horizon using a model of dynamics of the spacecraft governing an east-west position. A thruster controller to operate the thrusters according to their corresponding signals.

Energy efficient satellite maneuvering is described herein. One disclosed example method includes maneuvering a satellite that is in an orbit around a space body so that a principle sensitive axis of the satellite is oriented to an orbit frame plane to reduce gravity gradient torques acting upon the satellite. The orbit frame plane is based on an orbit frame vector.