A method (50) for orbit control of a satellite (10) in Earth orbit and for desaturation of an angular momentum storage device of the satellite, the satellite (10) including an articulated arm (21) suitable for moving a propulsion unit (31) within a motion volume included in a half-space delimited by an orbital plane when the satellite is in a mission attitude, the method (50) including a single-arm control mode using only the propulsion unit (31) carried by the articulated arm (21), the single-arm control mode using a maneuvering plan including only thrust maneuvers to be executed when the satellite (10) is located within an angular range of at most 180° centered on a target node in the orbit of the satellite (10), including two thrust maneuvers to be performed respectively upstream and downstream of the target node.

A method (50) for orbit control of a satellite (10) in Earth orbit and for desaturation of an angular momentum storage device of the satellite, the satellite (10) including an articulated arm (21) suitable for moving a propulsion unit (31) within a motion volume included in a half-space delimited by an orbital plane when the satellite is in a mission attitude, the method (50) including a single-arm control mode using only the propulsion unit (31) carried by the articulated arm (21), the single-arm control mode using a maneuvering plan including only thrust maneuvers to be executed when the satellite (10) is located within an angular range of at most 180° centered on a target node in the orbit of the satellite (10), including two thrust maneuvers to be performed respectively upstream and downstream of the target node.

A method for transferring a spacecraft (10), such as an artificial satellite, from an initial elliptical orbit (30) to a final geostationary orbit (50), the spacecraft taking at least one intermediate elliptical orbit (40) propelled by electric propulsion means (12, 13), the method includes: when the spacecraft is in an intermediate orbit, a nominal thrust step (410) in which the propulsion means generate nominal thrust while the spacecraft is on at least part of a first orbital arc (41) passing through the apogee A of the intermediate orbit, and a minimum thrust step (420), in which the propulsion means are partly stopped or slowed while the spacecraft is on at least part (43) of a second orbital arc (42) passing through the perigee P of the intermediate orbit, the two orbital arcs being complementary.

A cable (130) includes an electrical wire band (134). A parallel electrical wire (133) is formed by arranging a pair of a first electrical wire (131) and a second electrical wire (132) without being twisted together. The electrical wire band is formed by arranging a plurality of parallel electrical wires in a lateral row. In addition, between two adjacent parallel electrical wires, a second electrical wire of one parallel electrical wire is arranged adjacently to a first electrical wire of the other parallel electrical wire. Further, the electrical wire band is wound and accommodated in a spiral spring shape in a cable wrap mechanism (100).

Combined moderator-propellant technologies allow a dual-purpose fluid to act as both a nuclear moderator as well as a propellant in a nuclear reactor system, such as a nuclear thermal propulsion (NTP) system. By increasing the mass efficiency of the NTP system and improving the overall performance during operation, the combined moderator-propellant technologies improve valuable payload efficiency in the NTP system. Advantageously, the combined moderator-propellant technologies require little to no dedicated storage space for the majority of NTP system operation. For example, the combined moderator-propellant is ammonia (NH.sub.3), which satisfies moderation requirements as well as propulsion requirements for the NTP system.

An aircraft has a boom, a propulsion assembly coupled to a first end of the boom, and a first wing coupled to a second end of the boom. The propulsion assembly is coupled to the boom by a rotating joint. A second wing is optionally coupled to the rotating joint. The first wing is coupled to the boom by a rotating joint. The first wing is coupled to the rotating joint by a hinge. A vehicle with roll, pitch, and yaw maneuverability able to mirror the aircraft movements may be coupled to the second end of the boom. The vehicle body may be picked up with a vehicle chassis disconnected from the vehicle body. The boom houses an energy source to power the propulsion assembly. A rudder is coupled to the second end of the boom. A paddle is disposed between the propulsion assembly and the boom.

Systems and methods for a fully reusable upper stage for a multi-stage launch vehicle are provided. The reusable upper stage uses an aerospike engine for main propulsion and for vertical landing. A heat shield can include a plurality of scarfed nozzles embedded radially around a semi-spherical surface of the heat shield, wherein inboard surfaces of the plurality of scarfed nozzles collectively define an aerospike contour. The heat shield can be actively cooled to dissipate heat encountered during reentry of the upper stage.

An electrospray thruster with integrated propellant storage directly embedded into small satellite structural elements integrates the volume of the thruster into the volume of the rail.

A liquid rocket engine integrates tap-off openings at a combustion chamber wall to direct exhaust from the combustion chamber to a tap-off manifold that provides the exhaust to one or more auxiliary systems, such as a turbopump that pumps oxygen and/or fuel into the combustion chamber. The tap-off opening passes through a fuel channel formed in that combustion chamber exterior wall and receives fuel through a fuel opening that interfaces the fuel channel and tap-off opening. The tap-off manifold nests within a fuel manifold for thermal management. The fuel channel directs fuel into the combustion chamber through fuel port openings formed in the combustion chamber, the fuel port openings located closer to a headend of the combustion chamber than the tap-off openings.

A spacecraft refueling and storage system comprising a first tank and a second tank for storing propellant, a rotatable shaft to which the first and second tanks are mounted for rotating the first and second tanks about an axis of the shaft, and a drive motor for rotating the shaft so that upon rotation of the first and second tanks, liquid propellant is separated from gas in the propellant and settled to an outer portion of the first and second tanks.