Pressure-Fed versus Pump-Fed Propulsion Trade for the Aquarius Launch Vehicle

The baseline Aquarius consumables launcher derives its projected very low cost in part from avoidance of costly elements such as turbo-pumps, relying instead on pressure-fed propulsion, low margins, relaxed reliability, and sheer size. However, the current potential for simpler, low-cost pumps makes an assessment of a pump-fed design of interest. The analysis of alternative vehicle architectures and mission profiles in this paper concludes that pump costs up to $100K can be successfully offset by pump-enabled savings in other components and propellants while maintaining the Aquarius low cost paradigm. The mass, size, reliability, mission, and cost parameters for the two designs are reported. Also, a successful test of mass-efficient pressurization of LOX with GH2 is discussed, demonstrating an aspect of aggressive Aquarius design enabled by acceptance of relaxed reliability for launch of consumables.