SUBSTITUTION OF NTO BY HTP IN A BIPROPELLANT RCS

Abstract

The present article presents some theoretical considerations about the implications
due the change of the oxidizer in a bipropellant propulsion system. Preliminary
analysis conducted on the NTO/UDMH 400 N engine of a roll control system shows
that this engine could be capable of operation with HTP90 without significant
modification in the design. The new propellant combination is less toxic, can be
handled more easily, has a wider operational temperature range, and yields a more
amenable thermal environment from the combustion down to the exhaustion. Even
with a decrease in liquid film cooling, the HTP90/UDMH engine would present a
satisfactory reduction of the combustion chamber temperature and approximately the
same performance level of the original NTO/UDMH engine.