Systems and methods for equalizing fluid levels within a vent line and a propellant tank in which the vent line is located are discussed herein. The vent line includes a vent valve and an equalization valve. The vent valve can be included in a vent duct of the vent line. The equalization valve is included in a bottom wall (i.e., a low point) of the vent duct of the vent line. A controller is also included in the system to instruct a vent valve and the equalization valve to open and close.

Systems and methods for equalizing fluid levels within a vent line and a propellant tank in which the vent line is located are discussed herein. The vent line includes a vent valve and an equalization valve. The vent valve can be included in a vent duct of the vent line. The equalization valve is included in a bottom wall (i.e., a low point) of the vent duct of the vent line. A controller is also included in the system to instruct a vent valve and the equalization valve to open and close.

The invention relates to the field of cryogenics, and in particular to a device and a method for chilling down a cryogenic system (1). The chilldown device (100, 101) comprises a cryogenic fluid feed circuit (102, 103) and at least one atomizing nozzle (110) connected to said feed circuit (102, 103). The chilldown method includes feeding cryogenic fluid via a feed circuit (102, 103) to at least one atomizing nozzle (110) connected to the feed circuit (102, 103), spraying the cryogenic fluid through the at least one atomizing nozzle (110) as a spray (200) of cryogenic fluid, and projecting the spray (200) of cryogenic fluid against at least one zone to be cooled in the cryogenic system (1).

The invention relates to the field of cryogenics, and in particular to a device and a method for chilling down a cryogenic system (1). The chilldown device (100, 101) comprises a cryogenic fluid feed circuit (102, 103) and at least one atomizing nozzle (110) connected to said feed circuit (102, 103). The chilldown method includes feeding cryogenic fluid via a feed circuit (102, 103) to at least one atomizing nozzle (110) connected to the feed circuit (102, 103), spraying the cryogenic fluid through the at least one atomizing nozzle (110) as a spray (200) of cryogenic fluid, and projecting the spray (200) of cryogenic fluid against at least one zone to be cooled in the cryogenic system (1).

Embodiments of the present invention generally relate to a vapor retention device and methods of using a vapor retention device to manage propellant for upper stage space vehicles. The use of a vapor retention device, in combination with controlled acceleration, drives liquid propellant from a propellant supply line communicating with an upper stage main engine back into a propellant tank and establishes an insulating liquid/gas propellant interface that prevents the exchange of gaseous propellant across the interface.

Embodiments of the present invention generally relate to a vapor retention device and methods of using a vapor retention device to manage propellant for upper stage space vehicles. The use of a vapor retention device, in combination with controlled acceleration, drives liquid propellant from a propellant supply line communicating with an upper stage main engine back into a propellant tank and establishes an insulating liquid/gas propellant interface that prevents the exchange of gaseous propellant across the interface.

Rocket propulsion systems and associated methods are disclosed. A representative system includes a combustion chamber having an inwardly-facing chamber wall enclosing a combustion zone. The chamber has a generally spherical shape and is exposed to the combustion zone. A propellant injector is coupled to the combustion chamber and has at least one fuel injector nozzle positioned to direct a flow of cooling fuel radially outwardly along the inwardly-facing chamber wall. In addition to or in lieu of the foregoing features, the injector can include an oxidizer piston and a fuel piston that deliver oxidizer and fuel, respectively, to the combustion chamber, in a sequenced manner so that the oxidizer is introduced prior to the fuel.

A field of vehicles propelled by reaction, and more specifically to a method of suppressing the pogo effect in such a vehicle. A feed system for feeding a reaction engine of the vehicle includes a hydraulic accumulator enabling a selection to be made from among a plurality of predetermined operating levels, each corresponding to a different volume of gas. In the method, if a first reference criterion is not satisfied by the current level, the hydraulic accumulator is ordered to make a transition, preferably to an alternative level selected from among alternative levels for which the first reference criterion is satisfied and for which no hydraulic resonant frequency crosses any current mechanical resonant frequency during the transition.

A field of vehicles propelled by reaction, and more specifically to a method of suppressing the pogo effect in such a vehicle. A feed system for feeding a reaction engine of the vehicle includes a hydraulic accumulator enabling a selection to be made from among a plurality of predetermined operating levels, each corresponding to a different volume of gas. In the method, if a first reference criterion is not satisfied by the current level, the hydraulic accumulator is ordered to make a transition, preferably to an alternative level selected from among alternative levels for which the first reference criterion is satisfied and for which no hydraulic resonant frequency crosses any current mechanical resonant frequency during the transition.

A rocket fueling system includes an insulated jacket configured to removably couple to at least a portion of a rocket and form an enclosed space between the insulated jacket and the at least the portion of the rocket. The rocket fueling system also includes a cryogen inlet in the insulated jacket. The cryogen inlet is configured to receive a cryogen into an interior chamber of the insulated jacket. The rocket fueling system further includes a cryogen outlet in the insulated jacket. The cryogen outlet is configured to provide the cryogen from the interior chamber in the insulated jacket to the at least the portion of the rocket in the enclosed space. The rocket fueling system still further includes a gas outlet in the insulated jacket configured to exhaust the cryogen from the enclosed space, and a flammable gas sensor configured to detect a flammable gas at the gas outlet.