Oxidizer-rich liquid monopropellants for a dual mode chemical rocket engine

Abstract

The subject invention relates to oxidizer-rich liquid monopropellants based on ADN or HAN for a dual mode bipropellant chemical rocket engine. Such engines may be part of propulsion systems to be used in aerospace applications for 1) orbit raising, orbit manoeuvres and maintenance, attitude control and deorbiting of spacecraft, and/or 2) propellant settling, attitude and roll control of missiles, launchers and space planes.

Description

FIELD OF THE INVENTION[0001]The subject invention relates to oxidizer-rich liquid monopropellants based on ADN or HAN for a dual mode bipropellant chemical rocket engine. Such engines may be part of propulsion systems to be used in aerospace applications for 1) orbit raising, orbit manoeuvres and maintenance, attitude control and deorbiting of spacecraft, and / or 2) propellant settling, attitude and roll control of missiles, launchers and space planes.BACKGROUND OF THE INVENTION[0002]Dual mode rocket propulsion systems and dual mode rocket engines (also referred to as thrusters) are known in the art. Currently, many spacecraft use dual-mode propulsion systems, with bipropellant engines for larger thrust operations, and monopropellant engines for smaller thrust or when minimum impulse bit is important. In the art the choice of propellants which are suitable in both bipropellant and monopropellant engines are limited to a few very hazardous propellants. Such bipropellants comprise hydr...

AI Technical Summary

Benefits of technology

[0015]The inventive oxidizer-rich liquid monopropellant can be used to improve, in bipropellant operation mode, the performance of existing fuel-rich liquid ADN based monopropellants, such as LMP-103, LMP-103S, and FLP-106 (having the composition of 64.6% by weight of ADN, 23.9% by weight of water; and 11.5% by weight of MMF (N-methyl-formamide, aka mono-methyl-formamide), and existing fuel-rich liquid HAN based monopropellants.

[0016]Using the inventive storable low-hazardous oxidizer-rich liquid monopropellant together with a fuel-rich liquid monopropellant in bipropellant mode operation in a suitable dual mode chemical rocket engine, a propulsion system with comparable performance (i.e. in terms of total impulse for a given system mass) to the prior art dual mode chemical propulsion systems can be achieved while avoiding the use of the prior art hazardous propellants.

[0017]A major advantage of the oxidizer-rich liquid monopropellant of the invention is that it does not require a catalyst bed for the decomposition of the oxidizer-rich liquid monopropellant. For the decomposition of the fuel-rich monopropellant existing and well proven catalysts and catalyst beds currently used for the fuel-rich monopropellants can be used with the present invention.

Problems solved by technology

In the art the choice of propellants which are suitable in both bipropellant and monopropellant engines are limited to a few very hazardous propellants.

Both hydrazine (fuel) and nitrogen tetroxide (oxidizer), and their derivatives are extremely hazardous for humans as they are highly toxic, carcinogenic, corrosive, etc., and they are associated with significant concerns regarding the severe impact on the environment that they can cause in the case of spillage and emissions Therefore, the handling thereof and the safety requirements are extremely demanding, time consuming and costly.

Accordingly, it is therefore desirable to provide a propellant enabling a dual mode propulsion system avoiding the use of hydrazine, nitrogen tetroxide, and derivatives thereof However, so far, no viable rocket propulsion systems, rocket engines, and corresponding alternative propellants with performance comparable to the prior art hazardous hydrazine propellants have been realized.

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