Preliminary Analysis on the Influence of Iron Ingredient in Oxidizer on Reactivity for Satellite Bipropellant Propulsion System

Abstract

At bipropellant chemical propulsion systems, iron in oxidizer is one of the topics to be noted and controlled. Actually, to avoid the influence of the iron ingredient, several long term mission spacecraft such as interplanetary probes flush the oxidizer piping periodically. The major influence of steel contaminated oxidizer is known to be flow decay. Still, operation data of the HAYABUSA2 spacecraft indicates possibility of other drawbacks. This paper discusses its impact to the reactivity of the hypergolic propellant, especially for the propellant combination of N₂H₄/MON3, which is the case of HAYABUSA2. A series of open cup firing tests show that the reactivity deteriorates when the oxidizer is contaminated with iron.