Systems analysis of a microfabricated storable bipropellant rocket engine

Abstract

This thesis discusses the systems analysis of a storable bipropellant micro-rocket engine. Micro-rockets are built using MEMS technology and are projected to deliver a thrust to weight ratio up to two orders of magnitude greater than conventional rocket motors at small thrust levels making them very attractive for satellite propulsion applications and propulsion of very small launch vehicles. Several propellant combinations and engine cycles have been analyzed. Propellant combinations have been evaluated for a 125 atm combustion chamber on the basis of their performance, handling, and cooling properties. A non-toxic hydrogen peroxide/ethanol combination (302 s Isp) is chosen over a nitrogen tetroxide/hydrazine combination (322 s Isp) and a hydrogen peroxode/JP-7 combination (315 s Isp) on the basis of handling and cooling properties. Studies indicate that nitrogen tetroxide/hydrazine expander and decomposition topping cycles and hydrogen peroxide/ethanol and hydrogen peroxide/JP-7 decomposition topping cycles are feasible. It is shown that a 300 atm turbopump feed system is possible while further investigations on bearings and pump design are required to fully validate the concept. The analysis suggests that the storable bipropellant micro-rocket engine concept is feasible and identifies the engineering challenges ahead.