Pump performance requirement for the liquid helium orbital resupply tanker

The Liquid Helium Orbital Resupply Tanker (currently renamed to Superfluid Helium Tanker) will greatly enhance the lifetime of the space missions which require superfluid helium. The Superfluid Helium Tanker pump performance requirement is driven by the superfluid helium replenishment needs of the Space Infrared Telescope Facility (SIRTF). SIRTF is one of the space missions which will require on-orbit superfluid helium resupply in the 1990s. The Superfluid Helium Tanker will carry at least 10,000 L of superfluid helium and provide a minimum pump head of 170 torr (0 to 200 L/h) to cool SIRTF from 150 to 2 K. When the SIRTF tank starts to collect liquid, a minimum flow rate of 300 L/h with a pump head of 60 torr is required to fill the 4000-liter tank.