摘要:
A system located onboard a geosynchronous satellite (10) for detecting spin axis precession and developing thruster control signals for restoring the spin axis (12) to the desired attitude. Fuel economy is enhanced by timing the attitude trim maneuvers to coincide with certain station-keeping maneuvers.
摘要:
A first satellite (210(1)) and a second satellite (210(2)) are configured to be disposed together, in a launch configuration, for launch by a single launch vehicle. The launch vehicle includes a primary payload adapter (225) and the first satellite includes a secondary payload adapter (215). In the launch configuration, the first satellite is mechanically coupled with the primary payload adapter and the second satellite is mechanically coupled with the secondary payload adapter. Following injection into a first orbit by the launch vehicle, the first satellite separates from the primary payload adapter while the second satellite is mechanically coupled with the secondary payload adapter. The second satellite is detached from the secondary payload adapter of the first satellite only after an orbit transfer maneuver executed by a propulsions system of the first satellite. In the launch configuration, the mass of the second satellite is at least 30% of the mass of the first satellite.
摘要:
A method for maneuvering a satellite is provided and a system employing it is disclosed. The maneuvering includes performing two or more complementary north and south maneuvers to adjust an inclination of an orbit of a satellite by desired inclination correction ∆i. The complementary north and south maneuvers are performed by operating north and south thrusters of the satellite, which are respectively installed at panels of the satellite with respective cant angles from the north-south axis so as to produce significant radial component, to generate respective thrust delta-Vs for respectively accelerating the satellite by two or more predetermined supplemental velocities at two or more corresponding sidereal angles along the orbit. The maneuvering is characterized by shifting at least one of the sidereal angles of the two or more complementary maneuvers, to increase or decrease it, with respect to the optimal sidereal angle, which is perpendicular to the desired overall inclination correction ∆i, and thereby adjusting the inclination i of the orbit by the desired inclination correction ∆i while also adjusting an eccentricity e of the orbit by a desired eccentricity correction ∆e.
摘要:
A propulsion system for use with a satellite comprises a substrate, a communication network and a cluster of individually selectable solid fuel motors mounted on the substrate and operatively connected to the communication network. A controller is also operatively connected to the communication network and operative to select any one of more motors of the cluster of individually selectable solid fuel motors and transmit signals to fire the one or more motors of the individually selectable solid fuel motors. The substrate may have various configurations. The cluster of motors may comprise 10-1000 motors, which may be arranged in a rectangular array or other formation. Subsets of motors having different impulse capabilities may be employed. In this manner, lighter, smaller, flexible and more efficient propulsions systems may be provided for use in attitude control, etc. of satellites.
摘要:
La présente invention concerne un procédé (50) de contrôle d'orbite d'un satellite (10) en orbite terrestre, l'orbite du satellite (10) étant contrôlée en commandant selon un plan de manœuvre des moyens de propulsion (30, 31), comportant au moins un propulseur, et des moyens de déplacement (20, 21) desdits moyens de propulsion. Selon l'invention, ledit plan de manœuvre comporte au moins deux manœuvres de contrôle d'orbite, des forces de poussée des moyens de propulsion (30, 31) au cours desdites deux manœuvres de contrôle d'orbite étant de directions de poussée respectives non parallèles en repère inertiel, chacune desdites forces de poussée étant déterminée de sorte à contrôler simultanément l'inclinaison et la longitude de l'orbite du satellite ainsi qu'à former un moment adapté à désaturer un dispositif de stockage de moment cinétique dudit satellite dans un plan orthogonal à la direction de poussée de ladite force de poussée.
摘要:
According to some aspects of the subject disclosure, a spacecraft comprises first and second pluralities of thrusters. The pluralities of thrusters are attached to a spacecraft body by booms configured to move the first plurality of thrusters between stowed and deployed positions. The deployed position of the first plurality of thrusters is farther north than is the stowed position of the first plurality of thrusters. The deployed position of the second plurality of thrusters is farther south than is the stowed position of the second plurality of thrusters. The first plurality of thrusters comprises a first thruster and a second thruster separated from each other in an east-west direction. The second plurality of thrusters comprises a third thruster and a fourth thruster separated from each other in the east-west direction.
摘要:
Described herein are systems and methods for attitude determination using infrared Earth horizon sensors (EHSs) with Gaussian response characteristics. Attitude information is acquired by detecting Earth's infrared electromagnetic radiation and, subsequently, determining the region obscured by Earth in the sensors' fields of view to compute a nadir vector estimation in the spacecraft's body frame. The method can be applied when two sensors, each with known and distinct pointing directions, detect the horizon, which is defined as having their fields of view partially obscured by Earth. The method can be implemented compactly to provide high-accuracy attitude within small spacecraft, such as CubeSat-based satellites.
摘要:
An improved airship having a plurality of resilient gas bags & gas containers, a straight fuselage tubular hull, with an inner air passageway & propulsion means located therein, connecting air inlet, & outlet funnels fore, & aft, with air deflector cones axially positioned therein; further, propulsion, reverse, & directional rocket thrusters, additionally to typical airship components; furthermore, said airship having improved speed, maneuverability, efficiency, & adverse weather capability, reduced forward air resistance, & rearward drag in the air; and propulsive, attitudinal, & directional control in space.
摘要:
The present invention provides a method for station keeping of a spacecraft in a defined slot of a geostationary orbit. The spacecraft comprises at least two propulsion units having forces with components in an east-, a west-, a south-and a north-direction in a coordinate system fixed to the spacecraft. The method comprises the steps of placing the spacecraft in said defined slot of the geostationary orbit, and controlling a direction of an apogee vector originating at the center of the earth and pointing towards an apogee of the geostationary orbit of the spacecraft to point in a direction with an angle in the interval from -90 to 90 degrees from a direction of a sun vector originating at the center of the earth and pointing towards the sun, and simultaneously controlling the eccentricity and inclination of the geostationary orbit to be within the defined slot.