Space Systems/loral, LLC

Other

Loral Space & Communications, Ltd.

Walter S Gelon

John C Hall

Douglas Burr

Ahmed A Kamel

Darren R Stratemeier

Varouj G Baghdasarian

Scott W Tilley

Keith J Reckdahl

Seyed Tabatabaei

Peter S Simon

Robert Edward Helmer

Mohammad Saghir Munir

Daryl K Hosick

Sun Hur-Diaz

Eric V Werner

James J Sowers

William D Nations

Christian J Goodman

Joel Francis Boccio

Richard M Mills

Douglas G Burr

Gerrit Van Ommering

Steven Daniel Perez

Seyed A Tabatabaei

An imaging array fed reflector for a spacecraft is included in a spacecraft payload subsystem. The payload subsystem includes a multi-beam antenna including a reflector, a plurality of amplifiers, and a plurality of radiating feed elements, the feed elements configured as a phased array, illuminating the reflector, operable at a frequency having a characteristic wavelength (&#x3bb;), and configured to produce, in a far field at the reflector, a set of contiguous abutting beams. The amplifiers are disposed proximate to the plurality of radiating feed elements. Each radiating feed element has a respective coupling with at least one respective amplifier of the plurality of amplifiers. Each radiating feed element, together with the at least one respective amplifier, is disposed in a closely packed triangular lattice such that separation between adjacent radiating feed elements is not greater than 1.5&#x3bb;.

Imaging array fed reflector

Techniques for performing orbit raising, north-south stationkeeping, east-west stationkeeping, and momentum management with thrusters disposed on a spacecraft are disclosed. The spacecraft includes at least one thruster support mechanism (TSM), including a pointing arrangement and an elongated structural member, the structural member having a long dimension defining a first axis a proximal portion of the structural member is attached to the pointing arrangement each of the thrusters is fixedly coupled with a distal portion of the structural member. The pointing arrangement includes a first, second, and third revolute joint, the first revolute joint being rotatable about the first axis; the third revolute joint being rotatable about a third axis, the third axis being fixed with respect to the spacecraft; and the second revolute joint being rotatable about a second axis, the second axis being orthogonal to each of the first axis and the third axis.

Thruster support mechanism for satellite propulsion

A high capacity satellite having a launch configuration in which one or more antenna reflectors may be stored forward of a forward surface of the spacecraft and an on-orbit configuration in which a reflector boom may be rotated to displace the one or more antenna reflectors a substantial distance from the main body in the yaw axis direction and in a direction orthogonal to the yaw axis direction.

Reflector deployment techniques for satellites

A high capacity broadband service is provided from an Earth orbiting satellite having a payload that includes multiple large antennas, the satellite having an inverted configuration when deployed on orbit. The satellite has an aft surface proximate to a launch vehicle structural interface, a forward surface opposite to said aft surface, and a structure disposed therebetween. In a launch configuration, two or more deployable antennas are disposed, undeployed, on or proximate to and forward of the forward surface; on-orbit, the payload is operable when the satellite is disposed with the aft surface substantially Earth facing while the forward surface is substantially facing in an anti-Earth direction. Each deployable antenna is disposed, so as to be Earth facing, when deployed, in a position substantially forward and outboard of the forward surface.

High capacity broadband satellite

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.

Satellite having multiple aspect ratios

High data rata communications services are provided via a satellite system. Data is received from a user at a data rate greater than 30 Mbps over a communications link between the user and a first satellite, where the first satellite is one of a number of satellites within the satellite system; the data is forwarded over a crosslink from the first satellite to at least a second satellite within the satellite system; and the data is forwarded from the second satellite by a feeder link to a gateway located on the earth, said gateway being communicatively coupled to a terrestrial data network. The data is received from the user terminal by an antenna on the first satellite adapted for operation at a frequency associated with the feeder link.

Satellite system with enhanced payload capacity

A practical orbit raising method and system wherein a satellite quickly escapes the Van Allen radiation belts and payload mass and mission life are maximized. A satellite is launched that contains high thrust chemical propulsion thrusters, high specific impulse electric propulsion thrusters and a solar array. The satellite quickly escapes the Van Allen radiation belts by firing the high thrust chemical propulsion thrusters at apogees of intermediate orbits, starting from the transfer orbit initiated by a launch vehicle, to successively raise the perigees until the perigee clears the Van Allen radiation belts. The payload mass and mission life are maximized by firing high specific impulse electric propulsion thrusters to raise the satellite to near synchronous orbit, while steering the thrust vector and solar array to maintain the sun's illumination on the solar array. The chemical and/or electric propulsion thrusters are then fired to achieve geosynchronous orbit.

Practical orbit raising system and method for geosynchronous satellites

A spacecraft battery system arranges battery cells in two planes with a common mounting plate between them allowing for a more compact arrangement so the battery assembly can be removed from a limited mounting area resource of the spacecraft such as the north/south faces and placed remotely. Accordingly, a first battery assembly comprised of a plurality of battery cells in electrical continuity are mounted on and spread in a single plane over a first mounting surface of a planar mounting panel and a similarly constructed second battery assembly is mounted on and spread in a single plane over a second, opposed, mounting surface of that same planar mounting panel, the plane of the second battery assembly being spaced from the plane of the first battery assembly. The system includes a plurality of heat pipes embedded in the planar mounting panel and thermally connected with each of the battery cells for distributing heat uniformly across the planar mounting panel. The system also desirably includes a thermal radiator for radiating heat to deep space and heat conducting means thermally connecting the planar mounting panel to the thermal radiator means for drawing heat away from the planar mounting panel and to the thermal radiator means.

Three dimensional battery for space applications

A spacecraft comprises a first module including a first assembly of components and a second module including a second assembly of components and a thermal radiator. The second module is movable between a stowed position proximate the first module whereat the thermal radiator is only partially operative and a deployed position distant from the first module whereat the thermal radiator means is fully operative for dissipating waste heat to deep space for at least one of the first and second assemblies of components. In one embodiment, the first module includes a housing defining an interior cavity, the second module including a casing so shaped and dimensioned as to be telescopically received within the internal cavity of the first module and the second module being translationally movable along a deploying axis between the stowed position and the deployed position but incapable of mutual rotation about the deploying axis. In another embodiment, a spacecraft includes a plurality of discrete faces and comprises an equipment panel including an assembly of heat generating components which require cooling, a thermal radiator, and a connecting hinge mounting the equipment panel for pivotal movement between a stowed position proximate one of said faces whereat the thermal radiator is only partially operative and a deployed position distant from the face whereat said thermal radiator means is fully operative for dissipating waste heat from the assembly to deep space.

Satellite architecture with deployable electrical equipment

In an electric propulsion system used for transferring a satellite to its operational orbit, a solar array adjustment system is controlled to compensate on a continuous basis for the attitude gyrations required by electric thrust vector optimization. The solar array control operates to maintain the solar array in a perpendicular orientation to the sun vector for optimum power generation.

Solar array control for electric propulsion system

A practical stationkeeping method and apparatus wherein an electric propulsion system on a satellite is used to correct north-south drift and the majority of east-west drift which is caused by orbital eccentricity growth. A chemical propulsion system on the satellite is used to correct the remainder of east-west drift due to the growth of orbital semimajor axis. The method and apparatus eliminate the need for additional electric thruster burns in case of an electric thruster failure and therefore eliminates associated power and mass penalties.

Practical method and apparatus for satellite stationkeeping

In one embodiment, a thermal radiative system for an earth orbiting satellite including a plurality of faces intermittently exposed to maximum solar illumination comprises a thermal radiator is mounted on a face for discharging heat from a thermal load to deep space. A heat conductor extends between the thermal load and the thermal radiator. Thermal switches are operable for connecting the thermal load to the thermal radiator for cooling when the temperature of the thermal load is above a predetermined level and for disconnecting the thermal load from the thermal radiator when the temperature of the thermal load falls below the predetermined level. A shield including phase change management (PCM) material is thermally connected to the thermal load for drawing heat away therefrom. In another embodiment, first and second thermal radiators are mounted on first and second faces, respectively, of the satellite for discharging heat from the thermal load and the thermal load is sequentially connected to the first and second thermal radiators to achieve optimum discharge of heat from the thermal load. To this end, the thermal load is thermally connected to the first radiator so long as the first radiator is exothermic and thermally disconnected from the first radiator when the first radiator becomes endothermic and is thermally connected to the second radiator so long as the second radiator is exothermic and thermally disconnected from the second radiator when the second radiator becomes endothermic.

Sequenced heat rejection for body stabilized geosynchronous satellites

A three-axis stabilized spacecraft having roll, pitch, and yaw axes and when on station in orbit about the earth having a north face and a south face is equipped with a first and second thruster which may be electric thrusters. A first support device mounts the first thruster adjacent the north face and the first thruster is positioned a spaced distance away from the north face in a first direction parallel to the pitch axis and spaced from the pitch axis in a second direction normal to the pitch axis. A second support device mounts the second thruster adjacent the south face, the second thruster being positioned a spaced distance away from the south face in a third direction opposite the first direction and spaced from the pitch axis in the second direction. A gimbal mechanism pivotally mounts the first and second thrusters on the first and second support devices, respectively, for selectively positioning the attitude of the first and second thrusters. The spacecraft includes a system for performing one or more operations including the following: thrusting along the yaw axis to assist in reaching a geosynchronous orbit; reducing the stored angular momentum of the momentum wheels; and north-south station keeping of the spacecraft.

Multiple usage thruster mounting configuration

A battery system for an body stabilized satellite traveling in a geosynchronous orbit comprises east and second battery modules and similarly facing radiators for discharging beat to deep space. Heat conduction arteries connect each battery module to its associated radiator. An east thermal switch is operable for thermally connecting the first battery module to and from the east facing radiator. Similarly, a west thermal switch is operable for thermally connecting the second battery module to and from the west facing radiator. A computer selectively operates the east and west thermal switches such that, in one instance, for a time between the satellite's emergence from the earth's shadow and its position nearest the sun, the respective thermal switches thermally connect the first battery module to its radiator while thermally disconnecting the second battery module from its radiator. In another instance, beginning when the satellite is nearest the sun and ending as it enters the earth's shadow, the east thermal switch thermally disconnects the first battery module from its radiator while the west thermal switch thermally connects the second battery module to its radiator. In still another instance, beginning when the satellite is in the shadow of the earth, the battery modules are simultaneously thermally connected to their associated radiators. Charging of each battery proceeds while it is thermally connected to its respective radiator.

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Redwood City, CA, United States of America

Walter S Gelon