摘要:
The present invention consists of an active tie-rod device making it possible to hold and smoothly release space appendages. The active tie-rod device includes a fixed base, an active tie-rod screwed into the said fixed base, a retractable release mechanism for the active tie-rod making it possible, in the stowed position, to hold the said active tie-rod in place, and a nut for tensioning the assembly. The active tie-rod includes an internal heater, and consisting at least partially of a material with a high coefficient of thermal expansion, so that, under the action of the internal heater, the active tie-rod can expand, retracting the retractable release mechanism for the active tie-rod, and consequently allowing the smooth release of the said space appendages.
摘要:
A spacecraft may include a receive antenna, a transmit antenna having an antenna attitude adjuster, and a spacecraft attitude adjustor. The spacecraft may have a nominal orientation in which a yaw axis of the spacecraft, a roll axis of the spacecraft, and the radiator panels are substantially parallel to Earth's equatorial plane, in which the pitch axis of the spacecraft is substantially parallel to Earth's polar axis, in which the Nadir vector is in a yaw-pitch plane of the spacecraft, and in which the transmit antenna and receive antenna are oriented at angle φnom. The antenna attitude adjustor and the spacecraft attitude adjustor may correct an attitude of the transmit antenna to maintain a desired degree of the receive antenna and the transmit antenna steered toward a coverage region on Earth's surface.
摘要:
A preferred In Orbit Transportation & Recovery System (IOSTAR™) (10) includes a space tug powered by a nuclear reactor (19). The IOSTAR™ includes a collapsible boom (11) connected at one end to a propellant tank (13) which stores fuel for an electric propulsion system (12). This end of the boom (11) is equipped with docking hardware (14) that is able to grasp and hold a satellite (15) and as a means to refill the tank (13). Radiator panels (16) mounted on the boom (11) dissipate heat from the reactor (19). A radiation shield (20) is situated next to the reactor (19) to protect the satellite payload (15) at the far end of the boom (11). The IOSTAR™ (10) will be capable of accomplishing rendezvous and docking maneuvers which will enable it to move spacecraft between a low Earth parking orbit and positions in higher orbits or to other locations in our Solar System.
摘要:
The invention relates to devices for releasing the stacking tie-rods that are used for holding deployable structures, in particular solar panels of artificial satellites. The device of the invention is self-releasing in order to enable such deployable structures to be released via the top portion of the stacking column. The invention consists in holding together the members (101) that are to be deployed by means of a tie-rod (102) having a nut (111) screwed onto its free end. The force for holding the stack together is transmitted by modules (106, 107) which are themselves held together by said force. When the stacking tension is reduced, resilient means, such as two flat spring blades (112, 113), cause the modules to move away from the tie-rod, thus enabling the members of the deployable structure to be released.
摘要:
A Sequential Shunt Switching Regulation cell [S3R] adapted to connect a power source, such as a solar array panel (SAi), to a users bus (Vbus) under control of a signal (INCTRi). The cell (S3R) comprises a phase anticipator circuit (PAC) adapted to reduce the delay between the moment the control signal is received and the moment the power source is connected to the bus, modifying thereby the hysteresis due to parasitic capacitances of the cell and the solar array. Several such cells are included in a power supply arrangement including a power conditioning and distribution unit (PCDU) comprising also a mean error amplifier (MEA) adapted to detect the voltage (OUTS3R) at the user bus and to provide corresponding control signals to the cells. Owing to the phase anticipator circuits in the cells, double sectioning is avoided. In other words, a power source (SAi) is connected to the bus before the mean error amplifier requires the connection of a second one (SAj).
摘要:
A passive thermal control system maintains the operating temperature range of protected equipment within desired limits by controlling the conductive attributes of thermal interfaces and physical relationships within the system so as to achieve a desired thermal balance. In one embodiment, an integrated cell unit (100) includes a solar array (102), a Lithium ion cell (108) and an antenna assembly (114) such as a phased array antenna. In operation, a thermal gradient (116) is defined between the array (102) and the assembly (114) as the assembly (114) radiates heat from the array (102) into space. The operating temperature range of the cell (108) is controlled by appropriate design of the thermal interfaces between the cell (108) and the assembly (114) and/or interfaces within the assembly (114), such as a thermal interface associated with dielectric spacers provided between emitter pairs of the assembly (114).
摘要:
An In Orbit Transportation & Recovery System (IOSTAR™) (10) is disclosed. One preferred embodiment of the present invention comprises a space tug powered by a nuclear reactor (19). The IOSTAR™ includes a collapsible boom (11) connected at one end to a propellant tank (13) which stores fuel for an electric propulsion system (12). This end of the boom (11) is equipped with docking hardware (14) that is able to grasp and hold a satellite (15) and as a means to refill the tank (13). Radiator panels (16) mounted on the boom (11) dissipate heat from the reactor (19). A radiation shield (20) is situated next to the reactor (19) to protect the satellite payload (15) at the far end of the boom (11). The IOSTAR™ (10) will be capable of accomplishing rendezvous and docking maneuvers which will enable it to move spacecraft between a low Earth parking orbit and positions in higher orbits or to other locations in our Solar System.
摘要:
A compact spacecraft (10, 22) having a potentially long life in orbit as a result of its use of non-moving and solid-state components entirely or wherever possible. Amorphous silicon arrays (14, 24, 44) are used for solar energy collection. Because the arrays are not limited to a flat panel configuration, no movement is needed except for possible initial deployment. Phased arrays (12, 26) are used wherever possible for antenna arrays, in combination with torque rods (18, 3) for coarse attitude control of the spacecraft. Avionics modules (30, 50) are fabricated using large wafer-scale techniques and energy storage using long life battery or a solid-state capattery (52) technology. Propulsion is also effected with no moving parts, using waffle propulsion modules (20, 28, 54), which use elemental containers of propellant that is selectively ignited to supply propulsive force. This combination of features extends the useful life of the spacecraft beyond limits imposed primarily by mechanical moving parts, and by high levels of redundancy.
摘要:
A spacecraft includes a thruster coupled to an outward-facing portion of each solar array such that the thruster plume faces outward from the spacecraft. With the thruster located outboard of any erosion-sensitive surfaces on the spacecraft, the thruster exhaust is directed away from the spacecraft. Since canting of the thrusters is no longer required, the mounting of the thruster in the outward-facing portion of each solar array increases the effective Isp of the thruster. A thruster drive assembly is coupled to each solar array, adjacent to the thruster, for positioning the thruster such that any thruster exhaust is directed away from the spacecraft. A central supply tank is conveniently coupled to a central body portion of the spacecraft for providing a common propellant supply to each of the thrusters.
摘要:
An elliptical satellite system which carries out communication. The satellite orbits a height above the earth less than that necessary for geosynchronous orbits. When the satellite is near the apogee portion of its orbit, its velocity approximates the rotational velocity of the earth, and during that period it appears to hover over the earth. Each ground station on the earth always communicates a satellite within a predetermined position of its apogee, and hence that satellite appears to the ground station to hover over the earth. The satellite hence does not communicate with any earth station when it is outside of that apogee portion. During the times when the satellite is outside the apogee portion, its communication is therefore shut off to prevent any possibility of interfering with geosynchronous satellites. During this time, the power supply on the satellite is also used to charge a battery on the satellite. This enables the power supply to be made smaller by an amount equivalent to the duty cycle of the satellite: during the time which it is on.