Abstract: 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.

Abstract: Techniques for performing orbit raising north-south stationkeeping, east-west stationkeeping, and momentum management with thrusters disposed on a spacecraft. 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 second axis.

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 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: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.