Gaseous helium (GHe) is used in large quantities to support launch vehicle operations through onboard purging of cryogenic propellant storage tanks and purging of launch complex hardware. Additionally, some launch vehicles have onboard storage tanks of high pressure GHe, while other rockets using cryogenic propellants (e.g., Atlas V) use high pressure GHe to pressurize propellant tanks prior to engine burns. Sierra Lobo is developing their High Pressure Liquid Helium Pump System to provide the capability to provide GHe at the high flow and high pressures required at the launch complex facilities.


  • Compact enough for portability to supply vehicles at remote locations
  • Piston type liquid helium pump feeds a high-pressure vaporizer to convert the pressurized liquid helium to a gas for storage in distribution tanks
  • System consists of three main subsystems (feed system, pump, and vaporizer) interconnected with vacuum jacketed fluid lines and valves
  • Unique feature of the pump is the matching of the leakage flow rate past the pistons to the flow rate required for pressurized expulsion of the liquid helium from the storage dewar

Liquid Helium Pump

  • Flow rate increased through double-action (forward and backward) reciprocating piston pump driven by a linear motor mounted on a frame and enclosed in an insulated pipe
  • Cold leakage gas cools motor components
  • Motor provides some of the heat required for vaporization of the high-pressure fluid
  • Gaseous helium generated by the pump can be returned to the supply dewar in order to maintain pressure
  • Eliminates problematic interstage seals

High Pressure Vaporizer

  • Converts flow of high-pressure liquid helium into high-pressure cold gaseous helium through either an ambient air or electric vaporizer
  • Allows continuous operation of vaporizer for long durations while providing gaseous helium at high flow rates
  • Durable skid mounted design and function withstands a multitude of weather conditions, including extreme temperatures and humidity