Abstract: A large membrane space structure deployed and spanned by centrifugal force owing to the spin motion, contains a hub located at a central portion thereof and a sail including a plurality of petals attached to the hub by supports. Each of the petals has regions symmetrical to an imaginary center line passing through the center of the hub. Membranes are spanned on the regions. Each of the membranes is divided into parts of suitable shapes, and adjacent membranes are discretely connected to each other by bridge belts to suppress the residual crease strain. The petals are symmetric with respect to the center of the hub. Deployment force is provided in the circumferential direction by the introduction of imaginary tension lines. The petals may be connected to each other to help deployment.

Abstract: Solar panel includes solar cells affixed to one or more sheet elements and a frame for supporting the sheet elements, wherein the frame is provided with attachment members for attaching the sheet elements to the frame. The attachment members include one or more pretensioned strings, the sheet elements being attached to the strings. Preferably, the sheet elements are composed of flexible material and are attached to the string in a corrugated shape, wherein the sheet elements are provided with at least one row of apertures for weaving a string through successive apertures of the row.

Abstract: A power generation satellite converts electric energy generated from sunlight into a microwave and spreads and applies the microwave through a power transmission antenna of the power generation satellite to any desired area widely on earth. The beam width of the microwave is determined by the aperture area of the power transmission antenna placed in the power generation satellite. To spread and apply the microwave to a wide area, the power transmission antenna provided in the power generation satellite need not be a very large antenna having a diameter of several km or more like a power generation satellite power transmission antenna in a space photovoltaic power generation system in a related art.

Abstract: A solar battery module includes a plurality of solar cells connected to one another and a plurality of spaces each provided between adjacent solar cells, the plurality of spaces including at least one repair space which is larger than other spaces. A replacement solar cell includes an electrode and an interconnector electrically connected to the electrode, the interconnector including a connecting portion, which is positioned with respect to a connecting portion of an interconnector electrically connected to an electrode of an existing solar cell adjacent to the repair space so that the connection by the interconnectors is performed in the repair space. A method of replacing a solar cell includes the steps of simultaneously removing a plurality of existing solar cells arranged between at least two repair spaces, and simultaneously mounting a plurality of replacement solar cells to the region from which the plurality of existing solar cells are removed.

Abstract: A device is disclosed for reducing the risk of primary and secondary electrostatic discharges occurring in particular in the solar generators of spacecraft. A solar energy concentrator device for spacecraft includes a reflector for reflecting solar radiation onto a photovoltaic cell for converting solar energy into electrical energy and a heat transfer arrangement for transporting to a cold area heat energy stored by the cell following reception of solar radiation. One particular application of the device is to solar panels for satellites.

Abstract: High-output transmitters are applied to a power generation satellite and a transmission antenna apparatus and a transmission antenna having an array antenna with a small number of element antennas and a reflecting mirror antenna is applied, thereby providing a power generation satellite and a transmission antenna apparatus in a space photovoltaic generation system comprising transmission antennas each having performance equivalent to that of a phased array antenna with a smaller number of transmitters and a smaller number of element antennas than those of a transmission antenna implemented as a phased array antenna.

Abstract: An extendible solar generator has an extendible solar cell structure and an extendible support array structure which has a first cross member and is connected with a stowage housing for the solar cell structure. The support array structure can be rolled out independently of the solar cell structure and has guiding devices for rolling out the solar cell structure after the array structure has rolled out.

Abstract: A solar array including a carbon fiber mesh substrate is provided. The solar panels including a series of hybrid structures formed along the common and continuous substrate by sandwiching the substrate between a series of discontinuous upper and lower support layers. In order to construct the solar panels having such hybrid structure, a series of top support layers or upper face sheets is disposed on a upper surface of the substrate and between the folding sections. The solar cells are placed on top of the upper face sheets. Similarly, a series of lower support layers or lower face sheets are disposed on a bottom surface of the substrate and between the folding sections. The folding sections are the regions where the upper and lower face sheets discontinue and expose the underlying substrate. The solar array can be folded along the folding section when a bending force is applied over one of the hybrid structures.

Abstract: A flexible foldable solar generator having an array of a plurality of blankets carrying solar cells hingeably connected to be folded and unfolded. The solar cells are connected together by branches and the branches are connected by connector lines in inner and outer current conducting tracks system arranged outside the blankets. The branches connect the solar cells with the connecting lines in the outer track to form a U-shaped series connection of the cells and the U-shaped series connected cells are connected in parallel by the connecting lines in the inner track where they can be connected to energy systems of the space vehicle.

Abstract: Methods and apparatus for beaming power from one location to another are provided. Energy is used to power one or more lasers to provide a coherent, wide-aperture beam, which is directed to the receiving platform. Photovoltaic cells on the receiving platform convert energy of the laser beam into electrical energy. Receiving platforms are provided that take advantage of the higher energy density in the laser beam.

Abstract: A space photovoltaic power generation system including a plurality of power satellites arranged in space, each of which converts electrical energy, into which sunlight has been photoelectric-converted, into a microwave, and transmits the microwave to an electric power base. The space photovoltaic power generation system divides the plurality of power satellites into a number of power satellite groups and adjusts the amount of phase adjustment to be made to a microwave which each of the plurality of power satellites included in each power satellite group will transmit so that a plurality of microwaves from the plurality of power satellites included in each power satellite group are in phase with one another. The beamwidth of the plurality of microwaves can be reduced without increasing the area of the aperture of a transmission antenna of each of the plurality of power satellites.

Abstract: A space solar concentrator based on light-weight reflectors (3) attached to a honeycomb panel (1) is described. The integration of the reflectors (3) allows for a high modularity. Solar panel deployment is not perturbed by the reflectors (3) even with two-dimensional deployment concept. Each reflector (3) consists in small saw tooth aligned as rows (2) with solar cell rows in between. Low concentration is achieved with a high level of thermal control and a high optical efficiency. When small off-pointing occurs, the solar flux distribution is still the same on each cells. It guarantees a good electrical control and management on the whole panel. The reflectors (3) are preferably made of a thin film tight on a light-weight rigid frame deployed after launch. In another embodiment, the reflector is not deployable and is part of the panel substrate. A stowed configuration allows for superimposition of the solar panel.

Abstract: A solar array including a carbon fiber mesh substrate is provided. The solar panels including a series of hybrid structures formed along the common and continuous substrate by sandwiching the substrate between a series of discontinuous upper and lower support layers. In order to construct the solar panels having such hybrid structure, a series of top support layers or upper face sheets is disposed on a upper surface of the substrate and between the folding sections. The solar calls are placed on top of the upper face sheets. Similarly, a series of lower support layers or lower face sheets are disposed on a bottom surface of the substrate and between the folding sections. The folding sections are the regions where the upper and lower face sheets discontinue and expose the underlying substrate. The solar array can be folded along the folding section when a bending force is applied over one of the hybrid structures.

Abstract: Solar panel comprising solar cells affixed to one or more sheet elements and a frame for supporting said sheet elements, wherein the frame is provided with attachment means for attaching said sheet elements to the frame, wherein that, the attachment means comprise one or more pretensioned strings, the sheet elements being attached to said strings. According to the invention it is preferred that the sheet elements are composed of flexible material and are attached to the string in a corrugated shape, wherein the sheet elements are provided with at least one row of apertures for weaving a string through successive apertures of said row.

Abstract: The process of mitigation of spacecraft surface charging using polar molecules is invented. There exists a class of polar molecules which are electro-negative. This class includes the halocarbons, and includes the fluorocarbon refrigerants. They readily pick up electrons and become negatively charged molecules. In this invention, neutral polar molecular liquid is sprayed in fine mist form onto negatively charged spacecraft surfaces. The molecules pick up the electrons and evaporate away with the electrons.

Abstract: A space photovoltaic generation system including a plurality of power satellites arranged in space, each of which converts electrical energy, into which sunlight has been photoelectric-converted, into a microwave, and transmits the microwave to an electric power base. The system can thus transmit a microwave of high power to the electric power base. Each of the plurality of power satellites modulates the generated microwave so as to generate an incoherent microwave before transmitting it to the electric power base, thus reducing the power density of the electric power transmitted to the electric power base on the earth and hence a loss in the total amount of energy transmitted to the electrical power base on the earth.

Abstract: A space photovoltaic power generation system including a plurality of power satellites arranged in space, each of which converts electrical energy, into which sunlight has been photoelectric-converted, into a microwave, and transmits the microwave to an electric power base. The system can thus transmit a microwave of high power to the electric power base. As each of the plurality of power satellites changes its attitude in space, and its relative location therefore changes, each of the plurality of power satellites can adjust an amount of phase adjustment to be made to the microwave which each of the plurality of power satellites will transmit. A control satellite measures the location of each of the plurality of power satellites for the phase adjustment, and calculates the amount of phase adjustment for each of the plurality of power satellites. The control satellite then transmits the amount of phase adjustment to each of the plurality of power satellites.

Abstract: At least three stacked panels are articulated by means of adjacent members so that they can pivot toward a deployed configuration. A mechanism includes an immobilizer mounted on a first member, cooperating with a second member to lock the two panels in the deployed configuration and constrained to rotate with a lug which can rotate on the first member and is abutted against a surface of a member constrained to rotate with the second member and configured so that, when the deployed configuration is reached, the lug escapes from it and brings the immobilizer into contact with the second member to bring about locking. A first finger of the mechanism, which is constrained to rotate with the lug, cooperates with a second finger of the third panel to hold it stacked until the two panels reach the deployed configuration, at which time rotation of the lug releases the second finger.

Abstract: The process of mitigation of spacecraft surface charging using ionized water vapor is used, since it helps taking excess surface electrons away from a spacecraft surface, leaving practically no residue after complete evaporation.

Abstract: Disclosed is a solar cell for use in space, comprising compound semiconductors used as photovoltaic conversion material. The solar cell comprises a cover glass used for improving the radiation tolerance as a substrare for thin film deposition. The solar cell further comprises a crystalline thin film of the compound semiconductors directly formed on a surface of the cover glass for acting as the photovoltaic conversion material. The crystalline thin film of compound semiconductors is formed using a metal organic chemical vapor deposition system.

Abstract: A spacecraft solar array structure including at least one sheet of amorphous silicon (12, 24, 34) formed on a flexible backing film, a supporting structure (14, 22, 36), and a mechanism for reducing the bulk of the solar array structure to facilitate storage for launch and deployment of the structure in space. One disclosed embodiment of the invention includes a sheet of solar array material that deploys as cylindrical array (12) that does not need to be mounted on gimbals. In another embodiment, the solar array (24) is disposed on a rear surface of an antenna dish (22). In yet another embodiment, the supporting structure of the solar array (34) includes multiple antenna dipole elements (36).

Abstract: The power to weight ratio obtained with a spacecraft's solar array (3) is enhanced by a factor of at least two to five through use of support structure for individual solar panels or solar arrays (31a-17a) containing a curved outwardly bowed surface as deployed that packs essentially flat for storage. Defining a D-shaped wing (15a) in cross-section as deployed, the support structure (4 & 6) for a string of solar cells (10, FIG. 3) provides greater inertia and thereby greater rigidity than prior designs. One member (4) to the support structure is relatively flexible. One-hundred and eighty degree strain energy hinges (19) carried by the other support member (6) outwardly bows that flexible to define a curved sector when the support structure is released from the stowed condition in which the support structure is held relatively thin and flat.

Abstract: A foldable solar cell array (10′) with multiple hinged panels, each with a segment of solar cells on a first face of each panel. Maximum power demands are met by employing a shortened outermost panel (20′) to minimize mass and inertia of the array. In a folded configuration, power generated from solar cells on the shortened outermost panel (20′) are supplemented by power generated from an additional segment of solar cells on a second face of the panel adjacent to the outermost one.

Abstract: A radiation tolerant solar cell array module which can be efficiently assembled into a larger solar panel to generate power for a spacecraft the module includes at least first and second single-crystal solar cells. The first and second solar cells have front sides and back sides. At least one of the solar cells has a shallow junction N on P structure. A first contact is formed on at least the back side of the first solar cell. A second contact formed on at least the back side of the second solar cell. A conductor is in electrical communication with the first contact and the second contact. A substantially transparent ceria-doped cover overlays at least a portion of each of the solar cells. The cover remains substantially transparent when exposed to an AM0 space radiation environment. A substantially transparent adhesive is situated between the cover and the solar cell portions. The adhesive remains substantially transparent when exposed to a space radiation environment.

Abstract: A space solar cell includes a back surface electrode formed on a back surface opposite to a light receiving surface of a semiconductor substrate, and a dielectric layer formed between the back surface electrode and the semiconductor substrate. In the space solar cell, a plurality of openings are formed in the dielectric layer for establishing an electrical connection between the back surface electrode and the semiconductor substrate, and a ratio of an area occupied by the openings relative to an area of the back surface is within a range from 0.25% to 30%.

Abstract: The invention is at least a partially buoyant vehicle. In detail, the vehicle includes a gas-containing structure having an outer contoured surface. At least one solar panel assembly is mounted to the outer surface of gas-containing structure, the solar panel movable over a portion of the surface of gas-containing structure. A drive system is provided for moving the at least one solar panel assembly over the outer surface of the gas-containing structure. A track assembly mounted on the surface of the gas-containing structure for guiding the at least one solar panel assembly over the surface. Preferably the at least one solar panel assembly in the form of a flexible strip having first and second ends movable along the surface about the longitudinal axis of the vehicle.

Abstract: A space photovoltaic power generation system comprises a plurality of power satellites (1) arranged in space, each of which converts electrical energy, into which sunlight has been photoelectric-converted, into a microwave, and transmits the microwave to an electric power base. The system can thus transmit a microwave of high power to the electric power base. Each of the plurality of power satellites (1) modulates the generated microwave so as to generate an incoherent microwave before transmitting it to the electric power base, thus reducing the power density of the electric power transmitted to the electric power base on the earth and hence a loss in the total amount of energy transmitted to the electric power base on the earth.

Abstract: A space photovoltaic power generation system comprises a plurality of power satellites (1) arranged in space, each of which converts electrical energy, into which sunlight has been photoelectric-converted, into a microwave, and transmits the microwave to an electric power base (4). The space photovoltaic power generation system divides the plurality of power satellites (1) into a number of power satellite groups and adjusts the amount of phase adjustment to be made to a microwave which each of the plurality of power satellites included in each power satellite group will transmit so that a plurality of microwaves from the plurality of power satellites included in each power satellite group are in phase with one another. The beamwidth of the plurality of microwaves can be reduced without increasing the area of the aperture of a transmission antenna of each of the plurality of power satellites.

Abstract: A reconfigurable solar panel system having a plurality of solar cells arranged in a predefined pattern on a printed circuit board having a predefined pattern of interconnection paths to form at least one solar cell module. The solar panel being made of at least one solar cell module and having the capability to be configured and reconfigured by programming at least one integrated circuit that communicates with each and every solar cell on the solar module. The present invention is capable of monitoring, controlling, and protecting the solar panel, as well as being reconfigured before, during and after the panel is assembled. With the present invention it is also possible to reconfigure the solar panel after it has been employed in an application, such as a satellite that is in orbit.

Abstract: A space photovoltaic power generation system comprises a plurality of power satellites (1) arranged in space, each of which converts electrical energy, into which sunlight has been photoelectric-converted, into a microwave, and transmits the microwave to an electric power base (4). The system can thus transmit a microwave of high power to the electric power base (4). As each of the plurality of power satellites (1) changes its attitude in space, and its relative location therefore changes, each of the plurality of power satellites (1) can adjust an amount of phase adjustment to be made to the microwave which each of the plurality of power satellites will transmit. A control satellite (2) measures the location of each of the plurality of power satellites (1) for the phase adjustment, and calculates the amount of phase adjustment for each of the plurality of power satellites (1). The control satellite (2) then transmits the amount of phase adjustment to each of the plurality of power satellites (1).

Abstract: A solar generator especially for a spacecraft or space flight body has a plurality of first collector panels hinged to each other in a column extending in a first direction (D1) when the first collector panels are unfolded and a plurality of second panels coupled to the first panels so that the second panels can be unfolded in a second direction (D2) only after the first panels have been unfolded. The second panels are coupled to the first panels by journal struts or by hinges so that at least one first panel forms with at least one second panel, preferably with two or more second panels, a panel packet. The hinges (40) that articulate the first panels to each other permit unfolding the panel packets in said first direction (D1), whereupon the second panels in the individual packets can be unfolded in the second direction (D2).

Abstract: A power sphere preferably used as part of a nanosatellite is formed using a plurality of flat panels solar arrays interconnected together by rotating hinges to approximate a spherical shape for use as an enclosure of a payload. The solar array panels are supported by an extending internal strut. The spherical shape provides attitude insensitive solar energy collection and heat radiation.

Abstract: A spacecraft includes a spacecraft base structure having an externally facing, electrically conducting spacecraft surface, with the spacecraft structure including a solar cell array. A grounding structure has an externally facing, electrically conducting plasma grounding surface, and an electrical ground extends between the plasma grounding surface and the spacecraft base structure. In space, the spacecraft is oriented with the plasma grounding surface facing the sun. Electron photoemission from the plasma grounding surface balances electron charging of that portion of the spacecraft surface that does not face the sun, preventing electrical charging of the spacecraft relative to the plasma environment.

Abstract: A space solar cell includes a back surface electrode formed on a back surface opposite to a light receiving surface of a semiconductor substrate, and a dielectric layer formed between the back surface electrode and the semiconductor substrate. In the space solar cell, a plurality of openings are formed in the dielectric layer for establishing an electrical connection between the back surface electrode and the semiconductor substrate, and a ratio of an area occupied by the openings relative to an area of the back surface is within a range from 0.25% to 30%.

Abstract: A satellite solar array performance optimizing system that isolates a subsection of a solar array to provide power during transfer orbit operation, then connects the subsection in series with an adjacent section to maintain maximum power output at the satellite operating bus voltage. The isolated subsection is provided on an outer panel populated with solar cells in series calculated according to the parameters of the satellite mission to provide maximum power output matching the operating bus voltage. The outer panel subsection of solar cells is connected directly to the operation bus by a passive diode or a mechanical switch such as a latching relay. An adjacent or intermediate panel has a section of solar cells that are connected in series with the subsection of the outer panel and connected through a blocking diode to the operating bus.

Abstract: Electrostatic discharge (ESD) protection arrangement for a solar cell assembly (SCA) is suitable for the use as a component of orbiting solar generators. The SCA is constructed of a cover glass provided with a conductive vapor deposit, a bonding layer and a solar cell. At least a portion of a side face of the SCA is provided with a conductive layer which conductively connects the conductive layer on the cover glass and the solar cell.

Abstract: One embodiment of the present invention is a solar cell array intended for use in space. The solar cell array includes a lightweight, compressible concentrator which can be efficiently deployed. The solar cell array includes a first column of solar cells and a second column of solar cells. A reflective concentrator may be positioned between the first column of solar cells and the second column of solar cells. The reflective concentrator may include a thin film material, where the reflective concentrator is compressible to a first height when in the stowed position. A spring may be coupled to the concentrator, wherein the spring urges the reflective concentrator to a second height when the reflective concentrator is deployed.

Abstract: A shape memory alloy hinge assembly for deploying at least a first object in a controllable, substantially shockless manner is disclosed. Generally, the hinge assembly includes at least a first flexure member capable of moving from a first, folded configuration to a second, straightened configuration, and a controller for controlling the movement of at least the first flexure member as the first flexure member moves or reconfigures from the folded configuration to the straightened configuration.

Abstract: An improved solar panel for a spacecraft. The solar panel has a rigid base, at least one row of solar cells, and at least one elongated, collapsible, self-deploying reflector. Preferably, a plurality of rows and the reflectors are mounted on the face of the base and are generally parallel to each other in an alternating fashion. The deployed reflector forms a triangular shape having a first and second reflecting side that reflects radiation onto adjacent rows of solar cells. The collapsible reflector has a reflector sheet and an erector that deploys the sheet to form the triangular shape. The sheet is mounted to the base along its two lengthwise edges. The erector is mounted to the base beneath the sheet and adjacent to one of the sheet's lengthwise edges. The erector has a rigid erector arm that tilts upwardly to engage the underside of the sheet and to deploy the sheet into the triangular shape.

Abstract: A charging control device for use with a spacecraft solar array employs a field emitter array including a cathode and an anode; a first resistor coupled between the cathode of the field emitter array and a solar array common; and a second resistor coupled between the anode of the field emitter array and a solar array positive.

Abstract: A radiation tolerant solar cell array module which can be efficiently assembled into a larger solar panel to generate power for a spacecraft the module includes at least first and second single-crystal solar cells. The first and second solar cells have front sides and back sides. At least one of the solar cells has a shallow junction N on P structure. A first contact is formed on at least the back side of the first solar cell. A second contact formed on at least the back side of the second solar cell. A conductor is in electrical communication with the first contact and the second contact. A substantially transparent ceria-doped cover overlays at least a portion of each of the solar cells. The cover remains substantially transparent when exposed to an AM0 space radiation environment. A substantially transparent adhesive is situated between the cover and the solar cell portions. The adhesive remains substantially transparent when exposed to a space radiation environment.

Abstract: An improved solar cell interconnect comprises a first connecting portion for connection to a first solar cell and a second connecting portion for connection to a second solar cell immediately adjacent the first solar cell. A stress portion is disposed between the first and second connecting portions such that the stress portion can be positioned between the first and second solar cells. The stress portion has a plurality of alternating loop portions that form an undulating pattern.

Abstract: The power to weight ratio obtained with a spacecraft's solar array (3) is enhanced by a factor of at least two to five through use of support structure for individual solar panels or solar arrays (31a-17a) containing a curved outwardly bowed surface as deployed that packs essentially flat for storage. Defining a D-shaped wing (15a) in cross-section as deployed, the support structure (4 & 6) for a string of solar cells (10, FIG. 3) provides greater inertia and thereby greater rigidity than prior designs. One member (4) to the support structure is relatively flexible. One-hundred and eighty degree strain energy hinges (19) carried by the other support member (6) outwardly bows that flexible to define a curved sector when the support structure is released from the stowed condition in which the support structure is held relatively thin and flat.

Abstract: A power sphere has a curved surface upon which are mounted individual indivisible solar cells receiving differing amounts of solar illumination without solar tracking and pointing while providing respective differing amounts of solar power coupled through respective regulators onto a regulated bus for powering a connected load. The respective regulators continue to provide sufficient coupled power onto the bus even in the event of a failure of one or more of the solar cells thereby enabling graceful degradation of power delivery to the load for improved reliability of power delivery, particularly useful in space satellite systems.

Abstract: Flexible, lightweight reflective sheets are positioned to concentrate solar radiation upon spacecraft solar panels. The sheets are positioned with inner and outer spring members which urge each sheet towards a planar configuration and further urge the sheet in a rotation away from a solar panel face. Restraint members in the form of tethers limit this rotation to place the sheet in a deployed position in which it defines an angle with the panel to reflect solar radiation onto the panel face. The increased incident radiation permits a reduction of the number of solar cells with consequent savings in spacecraft cost and weight. The spring members are configured to permit rotation to a stowed position behind the solar panel. In this position, the tethers are received into guides which are configured to initiate automatic deployment of the spring members and their reflective sheets.

Abstract: A passive device for stabilizing the pointing direction of a spacecraft of the type comprising a pair of panels that are symmetrical about a gyroscopic stabilization axis, each panel having an auxiliary flap that is at least partially reflecting. Each of the auxiliary flaps is spaced apart from the plane of the corresponding panel and is disposed relative thereto in such a manner that during rotation of the spacecraft about the stabilization axis the area of the flaps that is illuminated by the sun's rays emitted along the solar ray direction Z.sub.s is modulated during rotation by the shadow of the corresponding panel.

Abstract: Solar panel assembly comprising a number of rectangular panels each carrying solar cells on one of the two main surfaces, said panels being interconnected by mutually parallel hinges such that the assembly from a first state, in which the panels are folded zigzag wise into a package, can be brought into a second state in which the package is unfolded and the panels are situated alongside each other in one plane. In the unfolded state each panel is curved in a direction parallel to the panel edges to which said hinges are attached.

Abstract: A concentrating coverglass allows efficient power generation for providing higher specific powers by space power arrays with weight penalties being countered by combining the functions of a solar concentrator and protective coverglass into a single element. A preferred frustoconical lens achieves a concentration ratio of about 4.5 at a thickness of about 1.0 mm. Efficient space power arrays with relatively wide tracking angle tolerance of up to about .+-.5.degree. using these coverglasses permit heavier payloads in the satellite's operating systems over traditional satellite designs.

Abstract: A device for angularly positioning a solar panel equipping a spacecraft such as a satellite, the panel being connected in hinged manner to the body of the spacecraft. The device comprises a heat-sensitive drive mechanism suitable for causing the panel to be displaced relative to the body of the spacecraft automatically as a function of the direction of incidence of the solar radiation on the spacecraft. The drive mechanism is suitable for taking up two states as a function of its temperature, and is so disposed on the spacecraft that a change in the direction of incidence of the solar radiation on the spacecraft is accompanied by a change in the temperature of the drive mechanism causing a change of a state therein and a change in the angular position of the panel tending to reduce the angle of incidence of the solar radiation on the panel.

Abstract: The device for tensioning sheet material applies a tensioning force around he outer edge of a sheet material to prevent the sheet material from wrinkling. These devices are attached to a supporting member forming the outer frame of a structure upon which the sheet material is to be attached and consist of tape strips or wires attached to or free sliding along the support member, sheet material of a differing material wrapped around the support member and attached to the main sheet material, with or without holes or slots, and extensions of the main sheet material around the support member, with or without heat created depressions along the border to relieve tearing stresses. Another tensioning member is a corner brace between perpendicular segments of the supporting member to remove wrinkles caused by manufacturing irregularities.