Abstract: A method of roll steering of a spacecraft to align an aspect of the spacecraft, such as the surface of solar arrays carried by the spacecraft, to the sun, is described. The roll steering occurs only when the sun is at an angle (?) relative to the orbital plane of the spacecraft and when the spacecraft is not eclipsed by a body it is orbiting. This dayside-only roll steering of the spacecraft increases the power efficiency of the spacecraft. A spacecraft may include a controller which causes an attitude control subsystem to steer the spacecraft about a roll axis to position the surface of the solar array such that an axis normal to the surface of the solar array is aligned with the direction to a sun when the sun is visible to the spacecraft, and maintain a fixed orientation of the spacecraft about the roll axis when the sun is not visible to the spacecraft.

Abstract: A satellite observation system and method of deploying a satellite system are disclosed. The system includes a plurality of observation satellites comprising one or more sensors, each of the plurality of observation satellites configured with at least a solar array and a mechanical stabilization element. Each of the plurality of observation satellites is constructed without positioning components. The plurality of observation satellites is positioned in a dawn/dusk sun-synchronous orbital plane about a celestial body such that the one or more observation sensors are oriented toward the celestial body.

Abstract: A satellite observation system and method of deploying a satellite system are disclosed. The system includes a plurality of observation satellites comprising one or more sensors, each of the plurality of observation satellites configured with at least a solar array and a mechanical stabilization element. Each of the plurality of observation satellites is constructed without positioning components. The plurality of observation satellites is positioned in a dawn/dusk sun-synchronous orbital plane about a celestial body such that the one or more observation sensors are oriented toward the celestial body.

Abstract: Techniques for deploying a plurality of smallsats from a common launch vehicle are disclosed where a structural arrangement provides a load path between an upper stage of the launch and the plurality of spacecraft. Each spacecraft is mechanically coupled with the launch vehicle upper stage only by the structural arrangement. The structural arrangement includes at least one trunk member that is approximately aligned with the longitudinal axis of the launch vehicle upper stage, a plurality of branch members, each branch member being attached to the trunk member and having at least a first end portion that is substantially outboard from the longitudinal axis; and a plurality of mechanical linkages, each linkage coupled at a first end with a first respective spacecraft and coupled at a second end with one of the plurality of branch members, the trunk member or a second respective spacecraft.

Abstract: A method of roll steering of a spacecraft to align an aspect of the spacecraft, such as the surface of solar arrays carried by the spacecraft, to the sun, is described. The roll steering occurs only when the sun is at an angle (?) relative to the orbital plane of the spacecraft and when the spacecraft is not eclipsed by a body it is orbiting. This dayside-only roll steering of the spacecraft increases the power efficiency of the spacecraft. A spacecraft may include a controller which causes an attitude control subsystem to steer the spacecraft about a roll axis to position the surface of the solar array such that an axis normal to the surface of the solar array is aligned with the direction to a sun when the sun is visible to the spacecraft, and maintain a fixed orientation of the spacecraft about the roll axis when the sun is not visible to the spacecraft.

Abstract: Techniques for deploying a plurality of smallsats from a common launch vehicle are disclosed where a structural arrangement provides a load path between an upper stage of the launch and the plurality of spacecraft. Each spacecraft is mechanically coupled with the launch vehicle upper stage only by the structural arrangement. The structural arrangement includes at least one trunk member that is approximately aligned with the longitudinal axis of the launch vehicle upper stage, a plurality of branch members, each branch member being attached to the trunk member and having at least a first end portion that is substantially outboard from the longitudinal axis; and a plurality of mechanical linkages, each linkage coupled at a first end with a first respective spacecraft and coupled at a second end with one of the plurality of branch members, the trunk member or a second respective spacecraft.

Abstract: A constellation of Earth-orbiting spacecraft includes a first spacecraft disposed in a first orbit and a second spacecraft disposed in a second orbit. Each of the first orbit and the second orbit is substantially circular with a radius of approximately 42,164 km. The first orbit and the second orbit have a respective inclination with respect to the equator within a range of 5° to 20°. The first orbit has a first right ascension of ascending node (RAAN1) and the second orbit has a second RAAN (RAAN2) of approximately RAAN1+90°.

Abstract: A spacecraft includes a plurality of deployable module elements, at least one of the deployable module elements including a robotic manipulator, the spacecraft being reconfigurable from a launch configuration to an on-orbit configuration. In the launch configuration, the deployable module elements are disposed in a launch vehicle in a first arrangement. In the on-orbit configuration, the deployable module elements are disposed in a second configuration. The spacecraft is self-assembled by the robotic manipulator reconfiguring the spacecraft from the launch configuration, through a transition configuration, to the on-orbit configuration. The deployable module elements may be in a stacked arrangement in the launch configuration and may be in a side-by-side arrangement in the on-orbit configuration.

Abstract: Described herein is a satellite communications system that includes: two or more satellites using laser communications, and a communications relay aircraft adapted for flying at altitudes above clouds. The communications relay aircraft includes: a laser communications module to communicate with the satellite using laser communication and a Radio Frequency (RF) communications module to communicate with RF equipment at or near ground level using cloud-penetrating RF communications. The RF communications module is configured to take data received as laser communication and generate a corresponding RF transmission containing the data. The laser communications module is configured to take data received as RF communication and to generate a corresponding laser transmission containing the data.

Abstract: A spacecraft includes a plurality of deployable module elements, at least one of the deployable module elements including a robotic manipulator, the spacecraft being reconfigurable from a launch configuration to an on-orbit configuration. In the launch configuration, the deployable module elements are disposed in a launch vehicle in a first arrangement. In the on-orbit configuration, the deployable module elements are disposed in a second configuration. The spacecraft is self-assembled by the robotic manipulator reconfiguring the spacecraft from the launch configuration, through a transition configuration, to the on-orbit configuration. The deployable module elements may be in a stacked arrangement in the launch configuration and may be in a side-by-side arrangement in the on-orbit configuration.

Abstract: A spacecraft operating in a low earth orbit having an altitude in the range of 160 to 800 km has a main body that includes heat dissipating electrical equipment and an earth-facing payload. Control surfaces on the spacecraft are articulated so as to: provide three-axis attitude control to the spacecraft main body using aerodynamic drag effects, such that the earth-facing payload is maintained in a selected orientation with respect to the earth; and control one or both of orbit altitude and period by articulating the control surfaces so as to regulate an amount of aerodynamic drag. The control surfaces include a first control surface disposed, in an on-orbit configuration, on a boom, the boom being mechanically coupled with the main body, and with one or both of a solar array electrically coupled with the electrical equipment and a thermal radiating array thermally coupled with the electrical equipment.

Abstract: A constellation of Earth-orbiting spacecraft, the constellation having an orbital maneuver lifetime life (OML), includes a first spacecraft disposed in a first orbit and a second spacecraft disposed in a second orbit, each of orbit being substantially circular with a radius of approximately 42,164 km and having a respective inclination with respect to the equator specified within a range of 10° to 20°. The first orbit has, at beginning of life (BOL), a first right ascension of ascending node (BOL-RAAN1) and the second orbit has, at BOL, a second RAAN (BOL-RAAN2) the BOL-RAAN1 and the BOL-RAAN2 being separated by a first angular separation ?-RAAN1. A first stationkeeping delta-V (?V1) applied over the OML to the first spacecraft, in combination with a second delta-V (?V2) applied over the OML to the second spacecraft, maintains the ?-RAAN1 approximately constant and an actual inclination within specification, and ?V1 approximately equals ?V2.

Abstract: Techniques for deploying a plurality of smallsats from a common launch vehicle are disclosed where a structural arrangement provides a load path between an upper stage of the launch and the plurality of spacecraft. Each spacecraft is mechanically coupled with the launch vehicle upper stage only by the structural arrangement. The structural arrangement includes at least one trunk member that is approximately aligned with the longitudinal axis of the launch vehicle upper stage, a plurality of branch members, each branch member being attached to the trunk member and having at least a first end portion that is substantially outboard from the longitudinal axis; and a plurality of mechanical linkages, each linkage coupled at a first end with a first respective spacecraft and coupled at a second end with one of the plurality of branch members, the trunk member or a second respective spacecraft.

Abstract: A low earth orbiting spacecraft (LEO spacecraft) operable in a first earth orbit includes a main body, a data collection payload, and a first directional antenna, each of the data collection payload and the first directional antenna being coupled with the main body. During a first period of time, the main body is oriented such that the data collection payload views a region of interest on the earth. During a second period of time, the main body and the first directional antenna are oriented such that the first directional antenna is directed toward a first ground station. During a third period of time, the main body and the first directional antenna are oriented such that the first directional antenna is directed toward a second spacecraft operating in a second orbit.

Abstract: A system includes at least two spacecraft disposed together for launch by a launch vehicle. In a launch configuration, a second spacecraft is mechanically coupled with the first spacecraft by way of an inter-spacecraft coupling arrangement (ISCA). The system is configured to be deployed following injection into a first orbit by the launch vehicle, while the second spacecraft is mechanically coupled with the first spacecraft. The first spacecraft includes a thruster configured to execute an orbit transfer maneuver from the first orbit to a second orbit, the thruster delivering thrust along a thrust vector. In an on-orbit configuration, the ISCA is switchable between a first mode that permits rotation of the first spacecraft with respect to the second spacecraft about a first axis of rotation that is approximately parallel with the thrust vector and a second mode that prevents rotation of the first spacecraft with respect to the second spacecraft.

Abstract: A stationkeeping strategy for a satellite disposed in a TAP orbit includes controlling parameters of the orbit such that, for a constellation of two satellites disposed in the orbit, the constellation provides substantially continuous coverage of a polar region. The stationkeeping strategy includes one or more of: establishing an initial Right Ascension of Ascending Node (RAAN) of the operational orbit such that naturally caused orbital drift results in a mid-life RAAN of approximately 0 degrees (360 degrees); and controlling Argument of Perigee (ARGP), only indirectly, by performing orbit maintenance maneuvers only to directly control one or more of the operational orbit apogee altitude, the operational orbit perigee altitude, and inclination within a respective required range.

Abstract: A constellation of Earth-orbiting spacecraft includes a first spacecraft disposed in a first orbit, a second spacecraft disposed in a second orbit, and a third spacecraft disposed in a third orbit. Each of the first orbit, the second orbit and the third orbit is substantially circular with a radius of approximately 42,164 km, and has a specified inclination with respect to the equator within a range of 5° to 20°. The first orbit has a first right ascension of ascending node RAAN1, the second orbit has a second RAAN (RAAN2) approximately equal to RAAN1+120°, and the third orbit has a third RAAN (RAAN3) approximately equal to RAAN1+240°. A fourth spacecraft is disposed in a fourth orbit that has a period of approximately one sidereal day, an inclination of less than 2°, a perigee altitude of at least 8000 km, and an eccentricity between approximately 0.4 and 0.66.

Abstract: A constellation of non-geosynchronous satellites are in a common orbit. Each time one of the satellites is at a trigger location, a new rolling wave of handovers is started that includes performing handovers of a group of dependent spot beams between adjacent satellites in sequence for pairs of adjacent satellites in a single direction around the orbit.

Abstract: A launch vehicle includes an upper stage and an integral fairing. In a launch configuration, the integral fairing is configured to enclose, between an aft portion and a forward portion, one or more payloads. The integral fairing includes a mechanical attachment with the upper stage proximal to the aft portion, and a nose cap proximal to the forward portion and a passive venting arrangement that equalizes pressures internal and external to the integral fairing. The integral fairing is configured to permit deployment of at least one payload, while avoiding: (i) separation of the integral fairing into two or more parts, (ii) separation of the integral fairing from the upper stage, and (iii) articulation of the mechanical attachment. The upper stage may provide single stage to orbit capability.

Abstract: Techniques for deorbiting a satellite include executing an orbit transfer maneuver that transfers the satellite from an operational orbit to an interim orbit. The operational orbit is substantially geosynchronous and has (i) an inclination of greater than 70 degrees; (ii) a nominal eccentricity in the range of 0.25 to 0.5; (iii) an argument of perigee of approximately 90 or approximately 270 degrees; (iv) a right ascension of ascending node of approximately 0; and (v) an operational orbit apogee altitude. The interim orbit has an initial second apogee altitude that is at least 4500 km higher than the first apogee altitude, and the interim orbit naturally decays, subsequent to the orbit transfer maneuver, such that the satellite will reenter Earth's atmosphere no longer than 25 years after completion of the orbit transfer maneuver.