A method for operating a satellite (10, 34) so that a predetermined amount
of propellant is left to perform end-of-life maneuvers is provided. A
first pressure differential is established between a first propellant
tank (74) and a second propellant tank (76) by pressurizing the first
tank (76) with a pressurant. Propellant is transferred from the first
tank (74) to the second tank (76). Using precise control during transfer
the amount of propellant in the tanks may be determined. The second tank
is used for orbit maintenance. The first tank is used for end-of-life
maneuvers. Propellant may be transferred between the tanks using a
latching process so that a predetermined amount of propellant may be
transferred from a non-empty tank to a full tank.