Abstract: A dozen or more orbiting solar generators stay in constant touch. They can be congregated rapidly in space at any desired secret location. Once congregated they all focus their energy to a death star. This death star is a newly launched ICBM with a microwave or laser collector. A laser generator uses this huge energy to project a non-nuclear death ray to a target. The target could be a city, a ship or a satellite. In the event of an asteroid approaching earth, this system could destroy an asteroid. In peacetime the orbiting solar generators supply electric power to an earth based power grid.

Abstract: A deployable and tracked solar array mechanism for restraining and releasing deployable solar panel arrays on a spacecraft is provided. The mechanism comprises a solar array drive mountable to the top side surface of the spacecraft. A solar panel array is pivotally attached to the solar array drive and positionable against the spacecraft. At least one notch is formed in at least one of the side edges of the solar panel array. A frame is slidably mounted to the spacecraft around the solar panel array. At least one tab extends from the frame over the solar panel array and releasably restrains the solar panel array. A spring mechanism urges the frame in a direction generally away from the solar array drive assembly.

Abstract: An adapter assembly for interconnection with a launch vehicle is provided. Generally, the adapter assembly is positioned between two separable components of a launch vehicle along a longitudinal axis of the launch vehicle to structurally interconnect the components. In an embodiment, a solar panel having a stowed state and a deployed state is interconnected to the adapter assembly. In a stowed state, the solar panel can be positioned within the interior space of the adapter assembly to utilize space within the launch vehicle that would otherwise not be fully utilized.

Abstract: A directionally-controlled roll-out elastically deployable solar array structure is disclosed. The structure includes one or more longitudinal elastic roll out booms that may be closed section or open section to allow for efficient rolled packaging onto a lateral mandrel. A flexible photovoltaic blanket is attached to a tip structure and to a lateral base support structure, but remains uncoupled from the longitudinal booms. The solar array system may be stowed simultaneously into a rolled package comprised of the roll out booms and the flexible planar blanket together, or onto independent rolls. Alternatively, the system may be stowed by rolling the booms, and accordion Z-folding the hinged flexible photovoltaic blanket into a flat stack. Structural deployment is motivated by the elastic strain energy of the roll out booms, and several methods of deployment direction control are provided to ensure a known, controlled, and unidirectional deployment path of the elastically unrolling booms.

Abstract: A solar panel (3) having a front face (31) for receiving solar radiation and a rear face (32), for use in a spacecraft (1). The solar panel is covered on the rear face (32) with a coating (4) having negative electric charge emissive property such that in use the coating expels electrons out of the rear face (32) of the solar panel (3), thus reducing the potential difference between the front face (31) and the rear face (32). A method of reducing potential difference between the front face (31) and the rear face (32) of the solar panel (3) by covering the rear face by said coating (4).

Abstract: A dual axis motorized solar tracking device that can be rotated over 360° and wherein the solar array panel thereof can be tilted from 90° to 10° and wherein the motorized portions of said device is controlled by an internally contained computerized controlling system that is programmed to follow the path of the sun at the installed location thereof and also to adjust the system to allow for any problems in weather. The internally contained computerized controlling device is electrically actuated from a plethora of sources including a separate panel on the solar array dedicated to recharging an energy storage cell system that will power up the internally contained and computerized controlling system. Alternatively, other power sources external to the device may also be employed giving this system a unique ability to keep on running while charging the energy storage cell system under any circumstances. A lithium-ion battery can be used as the rechargeable battery system.

Abstract: A method and system for solar powered charging of an electronic device is provided. Solar concentrators direct solar energy onto photovoltaic cells on an orbiting space station or a satellite in a geostationary orbit. The photovoltaic cells convert the solar energy to direct current (DC) electrical power. Energy generators convert the DC electrical power to generate energy waves, for example, microwaves. A space transmitter relays the energy waves to one or more earth stations. The electronic device transmits a locator beam indicating its current location. On receiving the locator beam, an earth station transmits the energy waves to the electronic device. A rectenna, in electronic communication with the electronic device, converts the energy waves to DC electrical power and directs the DC electrical power to a charger in electric communication with the electronic device. The charger receives the energy waves or the DC electrical power and charges the electronic device.

Abstract: A deployable solar panel assembly including a housing, a solar panel receivable in the housing, and first and second support structures disposed on the housing proximate the lateral edges of the solar panel. The first and second support structures each include an extension member connected to the housing and a pair of tethering members pivotably connected to the housing on opposite sides of the housing. The pair of tethering members are foldable against the housing and, upon deployment, a distal end of each tethering member projects outward from the opposite sides of the housing. The distal end of a deployed solar panel is supported in an extended position by the extension member, and supported against displacement out of the plane of the panel by tethers connected to the distal ends of the pair of tethering members. Spacecraft employing the deployable solar panel assembly and methods of deploying the assembly are also disclosed.

Abstract: A power distribution network is provided comprising ground-based microwave transmitters, receivers and microwave redirectors. The ground-based microwave transmitters have their own directional, focus and amplitude controllers for aiming a focused microwave beam at a microwave redirector. The microwave redirectors each have a receiving antenna and a plurality of transmitting antennae such that the redirectors transmit focused microwave beams to at least two different stations (for example, being either ground-based microwave receivers or other microwave redirectors).

Abstract: A multifunctional controller includes an onboard computer (OBC) and a power supply unit (PCDU) of a satellite. The controller includes reconfiguration functions for monitoring the correct functioning of components of an onboard computer of the satellite and for switching over between redundant components and/or turning off electrical loads of the satellite in the event of a malfunction. The controller also includes control functions for controlling and distributing energy to satellite components, which is designed for turning on and off the power supply to satellite components together with the reconfiguration unit.

Abstract: The chassis of a spacecraft has one side exposed to ultraviolet photons and another side shielded from the ultraviolet photons. An electrically conductive surface is disposed on the exposed side of the chassis and is electrically isolated from the chassis. A field-emission array device has a gate, an emitter array, a first terminal electrically connected to the gate, and a second terminal electrically connected to the emitter array. The first terminal electrically couples the gate to the electrically conductive surface on the exposed side of the chassis, and the second terminal electrically couples the emitter array to a surface on the shielded side of the chassis. The emitter array discharges electrons from the surface on the shielded side when a voltage difference in excess of a threshold voltage develops between the gate and the emitter array because of differential charging of the exposed and shielded sides of the chassis.

Abstract: A device for deploying and aiming structural elements designed to be placed in Earth includes at least one locking/unlocking device making it possible to deactivate the first coupling mode and to activate a second coupling mode allowing a portion of the device to be aimed at a target. The device uses: a plurality of structural elements linked together by articulations, the assembly forming an articulated arm linked to a payload via a root section; the articulations having at least one pivoting connection making it possible to have two consecutive structural elements pivot relative to one another; a motor making it possible to activate at least one pivoting connection of an articulation; and a system for coupling the articulations making it possible to link the pivoting of all of the structural elements comprising a first coupling mode.

Abstract: A method and apparatus for deploying a fixed and canted solar array of a satellite. The solar array is rotated in a first plane and about a first axis from a stowed position to a first position, rotated about a second axis orthogonal to the first axis from the first position to a deployed position determined by a deployment orbit of the satellite, and locked in the deployed position to prevent further motion of the solar array relative to a satellite body for the operational life of the satellite.

Abstract: A deployable structure that may include a slit-tube longeron and a flat panel coupled with the slit-tube longeron. The slit-tube longeron may include a tubular member having a slit that runs along the longitudinal length of the slit-tube longeron. The deployable structure may be configured to couple with a satellite. And the deployable structure may be configured to transform between a stowed state and a deployed state where the tubular member is substantially straight when the deployable structure is in the deployed state, and the tubular member is wrapped around the satellite when the deployable structure is in the stowed state.

Abstract: Collapsible solar array structures are disclosed that include a collapsible structure and detachable solar array. The solar array can be detached stowed separately from the collapsible structure. The collapsible structure can include a plurality of longerons and/or support structures. Longerons can have a slit along a longitudinal length of the longeron.

Abstract: Solar power satellite system for transmitting microwave energy to the earth and a method of arranging the solar power satellite system about the sun for same. The solar power satellite system comprises a space-based power generation unit disposed in a planetary orbit about the sun. A photovoltaic cell on the space-based power generation unit collects solar energy that is then converted to microwave energy to be beamed to the earth. A ground-based rectenna receives the microwave energy and converts the microwave energy to electricity that is transmitted to an end user. The solar power satellite system and method provides electrical power on earth day or night and regardless of atmospheric conditions. Also, surface area of the solar panel on the space-based power generation unit orbiting about the sun is much less than the surface area required of a ground-based solar panel or a solar panel in earth orbit.

Abstract: An example space-based power generation panel arrangement includes a first reflective panel and at least one heat pipe configured to communicate thermal energy to the first reflective panel and a second reflective panel. The heat pipe is configured to hinge the first reflective panel to the second reflective panel.

Abstract: The present invention relates to a device making it possible to study the solar corona on a space mission requiring the formation flight of two satellites: an occulting satellite (OCC), the role of which is to create an artificial eclipse of the sun from the point of view of a coronagraph (10) onboard a second satellite, called carrying satellite (COR). The invention presents the advantage of proposing a formation flight device intended for a solar coronagraphy mission comprising fixed solar panels (11a), requiring no deployment, thanks to a dissymmetrical accommodation of the coronagraph (10) reflected in a shifting of said coronagraph (10) to a side of the carrying satellite (COR).

Abstract: A high capacity satellite having multiple aspect ratios is configured to have at least two modules. Each module includes a first panel and a third panel facing, in an on-orbit configuration, respectively, toward north and south and having a width in an east-west direction (EW width); and a second and a fourth panel oriented, in the on-orbit configuration, respectively, east and west and having a width in the north-south direction (NS width). Each module has a respective aspect ratio of EW width to NS width, a first module is configured with a first aspect ratio, a second module is configured with a second aspect ratio; and the second aspect ratio is substantially larger than the first aspect ratio. At least one antenna reflector is disposed, during launch, proximate to at least one of the first and third panel of the second module.

Abstract: A solar concentrator includes a plurality of separate panels positioned between opposed support rods. Tension elements extend between the support rods and mount the plurality of panels.

Abstract: A cryogenic propellant depot and sunshield are provided for operation in earth orbit to fuel or refuel other space vehicles. The sunshield is deployed to effectively mitigate solar radiation emanating from the earth and the sun thereby providing a long term storage solution for cryogenic fluids prone to boil-off. The depot has supporting subsystems to include station keeping equipment and communication equipment so that the depot can be independently controlled. Inflatable booms are used to deploy the sunshield in a desired pattern around the depot.

Abstract: Apparatuses and methods for optimizing power generation of a solar array are disclosed. The bus voltage is regulated with a regulator controlled through one or more reference signals. When the power bus is being used by electrical systems that are tolerant of a higher variable voltage range, the bus voltage can be temporarily set higher by a commanded reference signal to allow additional solar array power to supply to the power bus. The peak power point may be identified through an established relationship with the solar array performance as a function of temperature, season and/or the age of the solar array. In addition, a reference signal controlled by one or more temperature sensors on the solar array may also modify the bus voltage set-point. Improved solar array power may be extracted from spacecraft beginning-of-life to end-of-life operations due to low insertion loss of a direct energy transfer scheme.

Abstract: A self rotating deployed film solar battery array includes film solar batteries, electrical cables, a center axle and connecting lines. A plurality of long strip shaped film solar batteries radiate to form a circle or a polygon-array. Two adjacent film solar batteries are linked by connecting lines. Each film solar battery is linked to the center axle by electrical cables. The film solar batteries are deployed and maintained in an array shape by a self rotating centrifugal force in space. The film solar batteries are coiling outside the surface of the center axle before their deployment. The unit weight of a thin film battery is only 1/30 of a traditional solar cell paddle.

Abstract: A high efficiency, environmentally friendly system comprising a plurality of photovoltaic solar collecting panels (PV panels) is disclosed. The system comprises an outer frame to which a plurality of inner frames are mounted to which the plurality of PV panels are attached. To minimize shadowing by the outer frame upon one or more PV panels, at least one PV panel may extend beyond an endpoint of the main frame. The system also comprises an outer frame rotation actuator that rotates the outer frame and an inner frame rotation actuator that rotates the inner frames and the plurality of PV panels. The solar tracking array frames disclosed herein help to improve the quality of the environment by conserving a variety of energy resources (e.g., fossil fuels, hydroelectric energy, etc.) The solar tracking array frames disclosed herein also help to reduce greenhouse gas emissions, as solar tracking array frames do not produce carbon dioxide byproducts.

Abstract: Structures and methods are disclosed regarding deployable structures with expandable longerons adjustably coupled with supporting structures such that an angle between the supporting structures can be adjusted. Such structures can include and/or be used for solar arrays, bridges, support structures, and more. These structures can be easily transported to a new location and deployed from the stowed configuration into a larger functional structure. In some embodiments these structures can use one or more longerons that can have two resting states: deployed and rolled.

Abstract: An apparatus and method are disclosed for dual Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) port small satellite designs. The apparatus and method provide payload volume for larger satellites. In one or more embodiments, the apparatus and method include a plurality of small satellite components, a payload adaptor ring, and at least one pivoting hinge system. In at least one embodiment, the plurality of small satellite components includes at least one payload, one bus, and/or one solar panel. The small satellite components are mounted on the payload adaptor ring. At least one pivoting hinge system connects together at least two of the small satellite components. Upon deployment of the small satellite components from the payload adaptor ring, at least one pivoting hinge system combines together at least two small satellite components, thereby creating at least one single larger satellite.

Abstract: An apparatus for trapping high-speed particles, such as space debris, is provided. The apparatus includes a first front tapping surface and at least one rear trapping surface. The front and rear trapping surfaces are arranged substantially parallel to each other and are spaced apart from each other in the normal direction.

Abstract: A system and method of generating and distributing power includes one or more microwave power transmitters at locations on Earth adjacent natural fuel or power resources such as natural gas, oil, solid fuel, or geothermal energy. The fuel or energy source is converted into electricity on site, and the electricity is then converted into microwave power beams transmitted from the microwave power transmitter towards a redirector satellite in orbit about the Earth. The redirector satellite then sends one or more microwave beams to rectennas located in consumer nations at appropriate sites for feeding the power grid or to additional redirector satellites for directing to rectennas located on the far side of the Earth.

Abstract: Deployable structures are disclosed having collapsible structural members that include a stowed configuration with a volume smaller than the expanded configuration. Such structures can include and/or be used for litters, bridges, support structures, solar arrays, and more. These structures can be easily transported to a new location and deployed from the stowed configuration into a larger functional structure. In some embodiments these structures can use one or more slit-tube longerons that can have two resting states: deployed and rolled.

Abstract: A deployable structure is disclosed. The deployable structure may include one or more slit-tube longerons; and one or more flat sheets coupled with the one or more slit-tube longerons. The one or more slit-tube longerons and the one or more flat sheets may be stowed by rolling the one or more slit-tube longerons and the one or more flat sheets together into a roll. In one embodiment, at least a portion of the one or more slit-tube longerons may be exposed when stowed. In another embodiment, the one or more slit-tube longerons may be manufactured from a shape memory material. These slit-tube longerons unroll into to a straight configuration when exposed to heat.

Abstract: A deployable structure that may include a slit-tube longeron and a flat panel coupled with the slit-tube longeron. The slit-tube longeron may include a tubular member having a slit that runs along the longitudinal length of the slit-tube longeron. The deployable structure may be configured to couple with a satellite. And the deployable structure may be configured to transform between a stowed state and a deployed state where the tubular member is substantially straight when the deployable structure is in the deployed state, and the tubular member is wrapped around the satellite when the deployable structure is in the stowed state.

Abstract: A system for generating power from sunlight collected substantially above the earth's surface comprises an airborne platform which supports an apparatus to collect sunlight, an apparatus to convert sunlight to electricity, and an apparatus to transmit the electricity to a selected location on the earth's surface. The airborne platform collects solar energy above the clouds and transmits the energy to a receiving station on the ground via a microwave transmission system, avoiding possible attenuating effects of clouds and pollution.

Abstract: One embodiment of the invention includes a spacecraft. The spacecraft comprises at least one solar array panel comprising an array of solar cell sections. Each of the solar cell sections can be configured to generate electrical power from received solar radiation. The spacecraft also comprises a solar array selection controller configured to selectively deactivate a portion of the array of solar cell sections to generate a torque on the spacecraft based on a difference in at least one of solar and thermal radiation pressure between an activated portion of the array of solar cell sections and the deactivated portion of the array of solar cell sections.

Abstract: An active vibration damping (AVD) control system for spacecraft provides a simple-to-implement and robust formulation that provides a novel damping control method for reducing spacecraft structural vibrations and improving antenna and instrument pointing. The AVD control system comprises an excitation signal generator configured to generate excitation input signals, and a damping model identification unit configured to receive system identification data and configured to produce control model parameters, the system identification data comprising the excitation input signals and information associated with motion of the spacecraft. The AVD control system further comprises an AVD control unit configured to receive the control model parameters, the AVD control unit configured to produce AVD control signals to control one or more actuators of the spacecraft.

Abstract: A system for generating power from sunlight collected substantially above the earth's surface comprises an airborne platform which supports solar power generation system to collect sunlight, convert the sunlight to electricity, and to transmit the electricity to a selected location on the earth's surface. The solar power generation system is coupled to the airborne platform by a support which can be manipulated by a control system to move the solar power generation system away from a shadow that might be cast by the airborne platform.

Abstract: Systems and methods are disclosed employing electric propulsion stationkeeping in a cyclical manner to better match the cyclical pattern of power generated by the solar array system. For a typical orbit design, e.g. a geostationary orbit, North-South stationkeeping can be intermittently suspended, tolerating some additional drift but yielding in a very significant reduction in the required solar power system. If necessary, stationkeeping can be supplemented with a chemical thrusters during off periods for the electric propulsion. Because of this, the overall electrical power margin for the solar array system design can be reduced without compromising the mission performance.

Abstract: An active vibration damping (AVD) control system for spacecraft provides a simple-to-implement and robust formulation that provides a novel damping control method for reducing spacecraft structural vibrations and improving antenna and instrument pointing. The AVD control system comprises an excitation signal generator configured to generate excitation input signals, and a damping model identification unit configured to receive system identification data and configured to produce control model parameters, the system identification data comprising the excitation input signals and information associated with motion of the spacecraft. The AVD control system further comprises an AVD control unit configured to receive the control model parameters, the AVD control unit configured to produce AVD control signals to control one or more actuators of the spacecraft.

Abstract: A system and method of generating and distributing power includes one or more microwave power transmitters at locations on Earth adjacent natural fuel or power resources such as natural gas, oil, solid fuel, or geothermal energy. The fuel or energy source is converted into electricity on site, and the electricity is then converted into microwave power beams transmitted from the microwave power transmitter towards a redirector satellite in orbit about the Earth. The redirector satellite then sends one or more microwave beams to rectennas located in consumer nations at appropriate sites for feeding the power grid or to additional redirector satellites for directing to rectennas located on the far side of the Earth.

Abstract: The present invention provides a photovoltaic cell comprising a GaInP subcell comprising a disordered group-III sublattice, a Ga(In)As subcell disposed below the GaInP subcell, and a Ge substrate disposed below the Ga(In)As subcell comprising a surface misoriented from a (100) plane by an angle from about 8 degrees to about 40 degrees toward a nearest (111) plane.

Abstract: A deployable structure is disclosed. The deployable structure may include one or more slit-tube longerons; and one or more flat sheets coupled with the one or more slit-tube longerons. The one or more slit-tube longerons and the one or more flat sheets may be stowed by rolling the one or more slit-tube longerons and the one or more flat sheets together into a roll. In one embodiment, at least a portion of the one or more slit-tube longerons may be exposed when stowed. In another embodiment, the one or more slit-tube longerons may be manufactured from a shape memory material. These slit-tube longerons unroll into to a straight configuration when exposed to heat.

Abstract: A cryogenic propellant depot and sunshield are provided for operation in earth orbit to fuel or refuel other space vehicles. The sunshield is deployed to effectively mitigate solar radiation emanating from the earth and the sun thereby providing a long term storage solution for cryogenic fluids prone to boil-off. The depot has supporting subsystems to include station keeping equipment and communication equipment so that the depot can be independently controlled. Inflatable booms are used to deploy the sunshield in a desired pattern around the depot.

Abstract: A solar powered aerial vehicle includes an elongated airframe incorporating lifting and control surfaces, a mechanism for propelling the airframe through the air such that lift developed by the lifting surface is equal to or greater than the weight of the aerial vehicle, a planar solar sail coupled to the airframe and having at least one surface adapted to collect solar energy during the day and to power the propelling mechanism with a first portion of the energy collected, and an apparatus such as a fuel cell/electrolyzer for storing a second portion of the solar energy collected by the solar sail during the day and for powering the propelling mechanism with the second portion of energy during the night. The vehicle is capable of continuous operation at northern latitudes and during the winter months for extended periods without landing or refueling.

Abstract: Solar cells include a substrate consisting essentially of silicon, a first junction disposed over the substrate, the first junction comprising at least one III-V material and having a threading dislocation density of less than approximately 107 cm?2, and a cap layer disposed over the first junction, the cap layer comprising silicon.

Abstract: A flexible inflatable hinge includes curable resin for rigidly positioning panels of solar cells about the hinge in which wrap around contacts and flex circuits are disposed for routing power from the solar cells to the power bus further used for grounding the hinge. An indium tin oxide and magnesium fluoride coating is used to prevent static discharge while being transparent to ultraviolet light that cures the embedded resin after deployment for rigidizing the inflatable hinge.

Abstract: A device is disclosed for sequencing the deployment of a deployable structure comprising a first body, at least one second body mobile relative to the first body, and at least one third body mobile relative to either the first body or the second body and disposed, in an at least partially folded position of the structure, against or between the first and second bodies. The device comprises a first member fixedly mounted on the third body and preventing its deployment when it is immobilized and a second member mounted on the second body and immobilizing the first member until the second body has effected a selected portion of a kinematic that drives it from an initial position to a final position.

Abstract: In one aspect, a space vehicle includes a structure configured to expand from a first configuration to a second configuration and at least two equipment compartments attached to the periphery of the structure. The structure includes at least one of an antenna mesh, a light-shielding mesh, an optical reflector mesh and a net. In another aspect, a space vehicle includes an antenna structure configured to expand from a first configuration to a second configuration and at least two equipment compartments attached to the periphery of the antenna structure. At least one of the at least two equipment components include a solar panel, a propulsion system and an antenna feed. In a further aspect, a space vehicle includes a payload element and at least two spacecraft-support structures attached to the periphery of the payload element. At least one of the at least two spacecraft-support structures includes a propulsion system and a tracking, telemetry and control system.

Abstract: A low-energy locking hinge mechanism operable with a spacecraft to support a deployable device, and to facilitate the deployment and locking of the deployable device, the hinge mechanism comprising: (a) a support base configured to couple to a structure of the spacecraft; (b) means for securing a deployable device to the support base, the deployable device being configured to rotate about a pivot axis; (c) a one-way clutch supported about the support base and operable with the means for securing, the one-way clutch being configured to facilitate one-way rotation of the deployable device from a stowed position to a deployed position, and to lock the deployable device in the deployed position, the one-way clutch having an inherent actuatable locking function configured to prevent backward motion; and (d) an actuation member operable with the one-way clutch to deploy the deployable device from the stowed position to the deployed position, the actuation member comprising an actuation energy sufficient to actuate

Abstract: A launch vehicle for a space station includes a crew transport vehicle having an orbiter, a cylindrical cargo module separable from the orbiter when in low earth orbit, and a first liquid fuel rocket engine section coupled to the cargo module operable to assist in placement of the launch vehicle in low earth orbit. The first engine section is separable from the cargo module in low earth orbit. The launch vehicle also includes booster rockets operable to place the launch vehicle in low earth orbit, and a liquid fuel tank, which is convertible to form living and working spaces for the space station. The space station includes rentable space that is used to recover launch and assembly costs associated with the space station.

Abstract: The chassis of a spacecraft has one side exposed to ultraviolet photons and another side shielded from the ultraviolet photons. An electrically conductive surface is disposed on the exposed side of the chassis and is electrically isolated from the chassis. A field-emission array device has a gate, an emitter array, a first terminal electrically connected to the gate, and a second terminal electrically connected to the emitter array. The first terminal electrically couples the gate to the electrically conductive surface on the exposed side of the chassis, and the second terminal electrically couples the emitter array to a surface on the shielded side of the chassis. The emitter array discharges electrons from the surface on the shielded side when a voltage difference in excess of a threshold voltage develops between the gate and the emitter array because of differential charging of the exposed and shielded sides of the chassis.

Abstract: One embodiment of the invention includes a spacecraft. The spacecraft comprises at least one solar array panel comprising an array of solar cell sections. Each of the solar cell sections can be configured to generate electrical power from received solar radiation. The spacecraft also comprises a solar array selection controller configured to selectively deactivate a portion of the array of solar cell sections to generate a torque on the spacecraft based on a difference in at least one of solar and thermal radiation pressure between an activated portion of the array of solar cell sections and the deactivated portion of the array of solar cell sections.