Abstract: An method of controlling thermal transfer between a first structure and a second structure may include a signal at a thermal switch. In response to receiving the signal at the thermal switch, a rotating plate may be rotated into one or more positions adjacent to a fixed plate to facilitate radiative thermal transfer between the rotating plate and the fixed plate. The rotating plate and the fixed plate may be in thermally conductive contact with respective ones of the first structure and the second structure.

Abstract: A method of controlling thermal transfer between a first structure and a second structure includes sending a command signal to a thermal switch and actuating an electric motor in response to receiving the signal. The electric motor may move a first thermally conductive member toward and/or in contact with a second thermally conductive member. The first and second thermally conductive member may be in thermally conductive contact with respective ones of the first and second structure.

Abstract: A propulsion system may be operated by determining pressure in a cryogenic liquid tank storing a fluid and cooling the cryogenic liquid tank in response to determining that the pressure is greater than a predetermined value. The cryogenic liquid tank may be pressurized by admitting a gaseous form of the fluid into the cryogenic liquid tank in response to determining that the pressure in the cryogenic liquid tank is less than a predetermined value.

Abstract: A propulsion system may be operated by determining pressure in a cryogenic liquid tank storing a fluid and cooling the cryogenic liquid tank in response to determining that the pressure is greater than a predetermined value. The cryogenic liquid tank may be pressurized by admitting a gaseous form of the fluid into the cryogenic liquid tank in response to determining that the pressure in the cryogenic liquid tank is less than a predetermined value.

Abstract: An oxygen-hydrogen pressurization system includes a cryogenic oxygen tank, cryogenic hydrogen tank, thermal switch, supercritical oxygen bottle, supercritical hydrogen bottle, and pressure management system and a thermodynamic vent system. The thermal switch permits heat to flow between hot and cool areas within the space vehicle to help facilitate pressure management within the cryogenic liquid oxygen tank and the cryogenic liquid hydrogen tank in conjunction with the higher pressure fluid from the supercritical oxygen tank and the fluid from the supercritical hydrogen tank and the added cooling from the pressure management system.

Abstract: An oxygen-hydrogen pressurization system includes a cryogenic oxygen tank, cryogenic hydrogen tank, thermal switch, supercritical oxygen bottle, supercritical hydrogen bottle, and pressure management system and a thermodynamic vent system. The thermal switch permits heat to flow between hot and cool areas within the space vehicle to help facilitate pressure management within the cryogenic liquid oxygen tank and the cryogenic liquid hydrogen tank in conjunction with the higher pressure fluid from the supercritical oxygen tank and the fluid from the supercritical hydrogen tank and the added cooling from the pressure management system.

Abstract: A cryogenic propellant storage tank system and method are disclosed that thermally couple LO2 and LCH4 tanks together by using either a single tank compartmentalized by a common tank wall or two separate tanks that are coupled together with one or more thermal couplers having high thermal conductivity. Cryogenic cooling equipment may be located only in the LO2 tank while the LCH4 is cooled by the LO2 tank interface. Embodiments of the invention may employ both LO2 and LCH4 liquid acquisition devices (LADs) for low-gravity use. In further embodiments, only the LO2 LADs may be integrated with thermal cooling equipment.

Abstract: Methods and apparatuses for causing thermal transfer between two structures on command including responding, by a thermal switch, to a command signal by moving a first set of one or more thermally conductive members into a position adjacent to a second set of one or more thermally conductive members, the first and second one or more thermally conductive members having thermally conductive contacts with the first and second structures, respectively.

Abstract: A liquid propellant management device for placement in a liquid storage tank adjacent an outlet of the storage tank to substantially reduce or eliminate the formation of a dip and vortex in the liquid of the tank, as well as prevent vapor ingestion into the outlet, as the liquid drains out through the outlet. The liquid propellant management device has a first member adapted to suppress the formation of a vortex of a liquid exiting the storage tank. A plate is affixed generally perpendicular to the first member, wherein the plate is adapted to suppress vapor ingestion into the outlet by reducing a dip in a surface level of the liquid leaving the tank. A second member is affixed to the second side of the plate. The second member ensures that the plate is wet with liquid and assists in positioning bubbles away from the outlet.

Abstract: A liquid propellant management device for placement in a liquid storage tank adjacent an outlet of the storage tank to substantially reduce or eliminate the formation of a dip and vortex in the liquid of the tank, as well as prevent vapor ingestion into the outlet, as the liquid drains out through the outlet. The liquid propellant management device has a first member adapted to suppress the formation of a vortex of a liquid exiting the storage tank. A plate is affixed generally perpendicular to the first member, wherein the plate is adapted to suppress vapor ingestion into the outlet by reducing a dip in a surface level of the liquid leaving the tank. A second member is affixed to the second side of the plate. The second member ensures that the plate is wet with liquid and assists in positioning bubbles away from the outlet.

Abstract: A liquid propellant management device for placement in a liquid storage tank adjacent an outlet of the storage tank to substantially reduce or eliminate the formation of a dip and vortex in the liquid of the tank, as well as prevent vapor ingestion into the outlet, as the liquid drains out through the outlet. The liquid propellant management device has a first member adapted to suppress the formation of a vortex of a liquid exiting the storage tank. A plate is affixed generally perpendicular to the first member, wherein the plate is adapted to suppress vapor ingestion into the outlet by reducing a dip in a surface level of the liquid leaving the tank. A second member is affixed to the second side of the plate. The second member ensures that the plate is wet with liquid and assists in positioning bubbles away from the outlet.

Abstract: The low gravity liquid level sensor rake measures the liquid surface height of propellant in a propellant tank used in launch and spacecraft vehicles. The device reduces the tendency of the liquid propellant to adhere to the sensor elements after the bulk liquid level has dropped below a given sensor element thereby reducing the probability of a false liquid level measurement. The liquid level sensor rake has a mast attached internal to a propellant tank with an end attached adjacent the tank outlet. Multiple sensor elements that have an arm and a sensor attached at a free end thereof are attached to the mast at locations selected for sensing the presence or absence of the liquid. The sensor elements when attached to the mast have a generally horizontal arm and a generally vertical sensor.

Abstract: A liquid propellant management device for placement in a liquid storage tank adjacent an outlet of the storage tank to substantially reduce or eliminate the formation of a dip and vortex in the liquid of the tank, as well as prevent vapor ingestion into the outlet, as the liquid drains out through the outlet. The liquid propellant management device has a first member adapted to suppress the formation of a vortex of a liquid exiting the storage tank. A plate is affixed generally perpendicular to the first member, wherein the plate is adapted to suppress vapor ingestion into the outlet by reducing a dip in a surface level of the liquid leaving the tank. A second member is affixed to the second side of the plate. The second member ensures that the plate is wet with liquid and assists in positioning bubbles away from the outlet.

Abstract: There is provided a vessel storing cryogenic fluid having a passive thermodynamic venting system for effectively and reliably transferring heat in a reduced-gravity environment. The storage vessel has a storage tank for holding the cryogenic fluid under pressure. The storage vessel is compartmentalized using a screen trap so that the heat exchanger of the venting system extends through a compartment which includes only the liquid phase of the cryogenic fluid. A screen gallery, screen trap and vane assembly cooperate to separate the gas and the liquid phases of the cryogenic fluid. The thermodynamic venting system includes a throttle device for reducing the temperature of cryogenic fluid. A conduit in contact with heat exchange elements transfers heat from the liquid phase of the cryogenic fluid to a relief valve for venting the heat external of the storage tank.