US3147592A - Hydrazine gas generator - Google Patents

Description

Sept. 8, 1964 1.. c. ROSE HYDRAZINE GAS GENERATOR 2 Sheets-Sheet 1 Filed Au 1. 1960 United States Patent 3,147,592 HYDRAZENE GAS GENERATQR Leslie C, Rose, Rocky Mount, Va, assignor to Thompson Raine Wooldridge Hue, Cleveland, (limit), a corporation of thin Filed Aug. 1, 1969, Ser. No. 46,440 4 Claims. (Cl. oil-39.46)

This invention relates to gas generation and is more particularly concerned with improved methods and means for generating gases from hydrazine for operating auxiliary power units of missiles, rockets and related air and space borne vehicles.

Heretofore, the design of gas generators for operating auxiliary power units of rockets, missiles and the like was seriously hampered and deterred by the fact that the number of liquid fuels and oxidizers which could be employed as the gas source was limited for any number of reasons. For example, the steady state operating requirement of such auxiliary power units dictated that fuels and oxidizers serving as the gas source have stable decomposition characteristics in a relatively small and compact generator, the size of which was determined by the particular application involved.

Another parameter requiring consideration before a fuel and oxidizer could be effectively employed for such purposes involved the type of decomposition reaction which would occur and the effects thereof on system performance, particularly when operation of the system was first initiated. Should the decomposition reaction be of a controlled explosive nature, the hazards involved are readily apparent.

A third requirement restricting the number of fuels and oxidizers which could be used for long range flight applications related to the derivative effects of the decomposition reaction. For example, large quantities of gases would be required for operation of larger size auxiliary power units employed with long range rockets, missiles and the like, thereby imposing heretofore unencountered requirements for high fuel and oxidizer flow rates and high gas flow rates.

The decomposition reaction conditions, therefore, would have to be of such a nature as to result in higher gas pressure which would rapidly reach a desired maximum operating level and remain constant without undue fluctuation caused by the fuel decomposition reaction.

Additionally, one of the most important factors in proper performance of long range missiles or rocket systems involves the initial ignition conditions which must be maintained to prevent initial flooding of the generator and the attendant danger of explosion. This is particularly true where a false start necessitates a repetition of the firing sequence. The expression false start is commonly used to refer to the termination of the firing sequence at any stage, and may be attributable to a variety of causes, for example, valve failure in either the auxiliary power unit fuel or oxidizer supply lines. As a result, various safety precautions must be taken to assure that the dangers of a false start are minimized.

Thus these factors, singly and collectively, seriously limit the number of liquid fuels and oxidizers which may be employed for large size auxiliary gas generators utilized for long range applications.

The proper selection of a fuel and oxidizer having application for gas generation purposes does not, however, completely eliminate the problems associated with such applications, since suitable ignition means must also be provided which are operatively compatible not only with the fuel and oxidizer reaction conditions involved, but also with other environmental conditions imposed by the design of the systems in which the generator is employed.

Squib devices, heated wire igniters and spark devices require elaborate electrical arrangements, the design of special electrical circuits, and, in general, contribute to the complexity and overall weight of the missile system thereby reducing system reliability.

In those systems where a screen coated with a chemical catalyst is employed as the igniter or ignition sustainer, the effects of component vibrations of the generator itself, of the supply lines connected thereto, coupled with the cumulative flight vibration effects of the vehicle in which employed, tend to weaken the coating on the screen to such an extent that the coating or catalyst pellets carried by the screen crumple and present a hazard of either a serious reduction in vehicle operating performance or possibly ultimate destruction of the vehicle.

By employment of my invention, simple and effective means are provided which permit the heretofore unknown use of hydrazine as the gas source fuel for a large size generator capable of supplying the abnormally large quantities of gases required for sustained and prolonged operation of large size auxiliary power units used in long range rockets, missiles, and related air and space borne vehicles.

Briefly stated, the present invention contemplates a gas generator system employing hydrazine as the fuel and an appropriate oxidizer, such as nitrogen-tetroxide, which is hypergolically reactive with hydrazine for producing the gases in the generator employed to operate auxiliary power units, such as turbo pumps. To initiate operation of the gas generator, to raise the operating temperature of the gas generator to a level sufficient to accelerate decomposition of the hydrazine and oxidizer and to raise rapidly the operating pressure of the exhaust gases to the desired level for auto-decomposition of the hydrazine, a predetermined portion of hydrazine is supplied to the gas generator to hypergolically react with a predetermined amount of oxidizer through pas sages formed in the generator.

Once the appropriate pressure and temperature have been established in the gas generator, the main fuel valve is automatically opened to permit fuel flow through a plurality of nozzles in an injection plate into a reaction zone of the gas generator.

The reacting mixture of fuel and oxidizer and burning gases produced thereby then fiow into a second zone defined by a pair of pervious dividers which retain therebetween a plurality of coiled wires which act as catalysts particularly when their glow temperatures have been reached thereby further promoting and enhancing decomposition of that portion of the mixture of hydrazine and oxidizer which may still be present in the burning gases.

The dividers serve the dual purposes of acting not only as flame stabilizers but also as means for reducing the size of any droplets of fuel and oxidizer which may be present in the gases in a still unburned condition. The burning gases then flow into a third zone and are discharged through an exhaust nozzle for operation of auxiliary power units, such as mentioned above.

Apparatus constructed in accordance with my invention is capable of delivering from about 1300 psi. to about 1500 psi exhaust pressure for operating turbines of auxiliary power units within less than one second after the main fuel valve has been opened and continuously maintain such pressure levels without pressure fluctuation. Hydrazine may be introduced into the chamber at a continuous flow rate of about 89 g.p.m. while under a pressure of about 1670 psi. At this rate, the decomposition reaction in the generator chamber is substantially stable, and sustained vehicle operation at these high flow rates and pressures are maintained without significant pressure fluctuations.

It is therefore an object of the present invention to provide improved gas generation means having special applicability in large size auxiliary power units for long range missile, rocket and related air and space-borne vehicles.

It is another object of the present invention to provide a hydrazine gas generation system having stable decomposition reaction characteristics in a relatively small and compact gas generator.

It is a further object of the present invention to provide hydrazine gas generation apparatus operating at high fluid fuel and gas flow rates and under high supply pressures.

Another object of the present invention is to provide effective starting of a hydrazine gas generator without the hazard of explosive hydrazine decomposition.

It is a further object of the present invention to provide a hydrazine gas generator device having starting characteristics which reduce the danger of explosion in the case of a false start.

It is a further object of the present invention to provide gas generation means wherein hydrazine fuel to be supplied under high pressures is not introduced into the gas generator device until the chamber reaction conditions are established.

A still further object of the present invention is to provide a method of generating hydrazine gases flowing at a gas rate which is substantially constant throughout the operating time.

It is a further object of the present invention to provide a hydrazine gas generation system which is simple and compact in construction and effective and constant in operation.

These and other objects, features and advantages of the present invention will become more apparent upon a careful consideration of the following detailed description, when considered in conjunction with the accompanying drawing, wherein like reference characters and numerals referred to like or corresponding parts throughout the several views.

On the drawing:

FIGURE 1 is a view in partial section illustrating a gas generator constructed in accordance with my invention.

FIGURE 2 is a view in partial elevation illustrating the injection head of the device of FIGURE 1.

FIGURE 3 is an end view taken along lines IIIIII of FIGURE 1.

FIGURE 4 is a schematic view illustrating the gas generator system of the present invention.

As shown on the drawing:

As appears in FIGURE 1, a gas generator, generally indicated by the reference numeral defines a decomposition chamber separated into three zones 10a, 10b and 100 respectively.

Zone 1% may be considered the initial decomposition zone and is defined by the end wall 12 which carries the injection assembly and a wire mesh screen 13, FIG- URE 1, which, if desired, may also comprise a plurality of wire mesh screens, suitably secured to the housing chamber wall as by welding. The second zone 10b of the decomposition chamber is defined by the mesh screen 13 and a perforated retaining plate 15, FIGURE 1, suitably secured to the inner chamber defining wall. Randomly positioned within the second zone 10b for completely filling the volume thereof is a plurality of metallic wires or coils 16 which act as a catalyst to propagate decomposition of the hydrazine in the chamber once the glow temperatures of the wires have been reached. The wires or coils 16 are packed in the second zone 1% between the dividers 13 and 15 in such a manner that gas fiow therethrough is permitted. The third zone 10c of the chamber is defined by the retainer plate 15 and the chamber end wall 16a which has radially extending therefrom in communication with the chamber an outlet 17 connected to a flange carrying conduit 18 which, depending upon the particular application involved, may be connected to a turbine or similar means requiring gas initiated motive power.

For ease of assembly, the chamber housing may be constructed in two parts 19 and 20, each of which is provided with complementary threads, as shown.

The end 2% of the housing assembly which supports the injection nozzle assembly is provided with a plurality of nozzles 21 arranged in concentric series. These nozzles are adapted to introduce hydrazine fuel into the decomposition chamber. An end cap 22 is suitably secured to the end wall 20 to define an annular chamber 24 providing thereby a manifold for supplying fuel to the nozzles 21 through a port communicating therewith and with a fuel feed line.

Centrally located within the chamber 24 is a generally cylindrical housing 25 defining a chamber 25a which communicates through a nozzled aperture 25b with the disassociation chamber for supplying a metered quantity of hydrazine thereto for purposes hereinafter described The chamber 25a communicates with a hydrazine fuel line through a fitted conduit 2'7.

Adjacent the fuel inlet conduit 27 is a fitted conduit 28 for introduction of an oxidizing agent hypergolically reactive with hydrazine into a main passage 28a formed in the housing adjacent the fuel chamber which communicates with an annular passage 2% which feeds a plurality of oxidizer injection passages 28c which are annularly arranged concentric with the fuel chamber. An oxidizer injection nozzle 29 is fitted in each of the inlet passages 280, each of the nozzles having an inwardly flared outlet for supplying the oxidizer in impinging contact with fuel injected from the fuel chamber 25a.

As appears in FIGURE 4, the gas generator 16 may be provided with a supply system including an oxidizer source 30 and fuel source 31. Conventional pump means 32 and 33 may be provided to supply the oxidizer and fuel respectively to the gas generator 10.

The gas generator communicates with the oxidizer source 30 through the conduit 28 which may be provided with a one-way check valve 34 and a main valve 40 for control of flow to the generator. Similarly, the gas generator 111 communicates with the fuel source 31 through a conduit 35 which may have positioned therein a oneway check valve 36. Conduit 35 has positioned therein a main valve 37. Conduit 35 also communicates with the generator starting fuel chamber 25a, as shown in FIG- URE 1, through a conduit 38 having a one-way check valve 39 therein. Thus valves 34, 36 and 39 permit fiuid flow to the generator and prevent return flow through the lines to the oxidizer and fuel sources respectively. The starting fuel conduit 38 has a branch conduit 38a which supplied a portion of the starting fuel to the main fuel manifold 24 (FIGURE 1) to cool the manifold during the ignition starting period. A valve 381) is provided to control by-pass of fuel to the fuel manifold as is a check valve 330.

Conventional control valve means 41 may be provided to regulate actuation of the main fuel valve 57, main oxidizer valve 4% and by-pass valve 381;. Valve means 41 may be energized from a remote source such as the autopilot system of the vehicle with which the gas generator is employed in response to the gas pressure requirements of the generator 111 or associated components. Thus the opening and closing of the main oxidizer and fuel valves and by-pass valve 381) may be synchronized so that the fuel and oxidizer are supplied to the gas generator in the desired proportions to ensure proper initiation of decomposition therein. Similarly, the pumps 32 and 33 respectivcly may be actuated by the control means 41 for proper synchronization of fuel and oxidizer flow to the gas generator through the main valves.

In operation, the control means 41 are energized and the pumps actuated to force fuel from the oxidizer source 30 and fuel source 31 through the conduits 28 and 35 respectively upstream of the valves 40 and 37. The control means 41 open the normally closed oxidizer valve 40 and open the conduit 35 downstream of the valve 37 for communication with the starting fuel line 38. The oxidizer and fuel therefore are metered through the lines 28 and 38 respectively into the primary or initial ignition zone a (FIGURE 1) where contact therebetween results in hypergolic decomposition establishing the required chamber conditions for initiating auto ignition of hydrazine when introduced from the main fuel line. Valve 38b is similarly opened to permit flow to the manifold 24 (FIG- URE 1).

It has been discovered that the hydrazine decomposition process includes at least two imperceptible steps wherein hydrazine is first decomposed to ammonia and the elemental forms of nitrogen and hydrogen and then the ammonia, in the decomposing environment and at the hydrazine decomposition temperature, decomposes into the elemental forms of nitrogen and hydrogen, all in the gaseous state. The initial decomposition of hydrazine results in reaction or decomposition chamber temperatures which are sufficient to promote secondary decomposition of the ammonia component and, the ammonia decomposition being endothermic in nature, results in a lowering of the reaction or decomposition chamber temperature to levels permitting the utilization of lower weight and more readily available materials for exhaust nozzles and gas generator conduits. Additionally, if hydrazine is used as the gas generation means for a turbine assembly, the reduction in temperature of hydrazine disassociation permits introduction of the hot gases from the gas generator directly into the turbine, eliminates the requirement for turbines constructed of expensive and difficulty obtained refractory materials and alloys, eliminates the requirement for cooling means for the gas generator exhaust conduit, and eliminates the requirements for pressure regulators between the exhaust conduit and the turbine thereby further eliminating the differences in the effects of induced vibrations on the generator and turbine which have a decided effect on turbine and generator performance since the mode of vibration of each may be different. With my invention, the gas generator may be mounted adjacent the turbine means and eliminate the latter problem. Thus hydrazine containing fuels, because of the hydrazine disassociation phenomenon, are advantageously employed as fuels for rockets, missiles and related air and space-borne vehicles.

Three types of vibrations have been observed in various rocket thrust chamber assemblies. First, chamber pressure oscillation with relatively low frequencies of to 0.1 cycles per second which alternately increase and decrease injection pressure drop, vary propellant fiow and in turn vary chamber pressure. The second type appears to be caused by excitation of the natural frequency of the metal parts of the combustion chamber and associated elements. The third type is a high energy vibration associated with the combustion process. These oscillations may become so violent as to cause structural failure of components and attached equipments in a very short time, usually less than one second. Additionally, the induced vibrations of the natural frequency of the vehicle in flight contribute to the overall vibrations acting in and on the combustion chamber. Means heretofore employed to avoid the effects of these various vibrations have proved ineffective for large size gas generators proposed for the purpose of supplying abnormally large quantities of gases for driving large size rocket engine turbopumps or for pressurizing the fuel and oxidizer tanks of intercontinental ballistic missile systems.

As far as I am aware, a large size generator, employing hydrazine as the propellant, which will withstand the vibrations encountered in the operation of large size rockets and the like and which will be operable at pressures of approximately 1500 p.s.i. at a maximum flow rate of approximately 89 g.p.m. has heretofore not been developed.

The generator of the present invention withstands such vibrations inasmuch as the generator employs metallic decomposition catalysts, and has extremely smooth performance over a wide range of propellant mixture flow conditions. In addition, the start up flow conditions may be maintained indefinitely.

In starting or initiating decomposition of a liquid fuel system, the starting procedures must be accurately controlled so that a smooth and even combustion initiation is achieved. Thus, conditions of starting become critical, since an unignited explosive mixture of propellants in the combustion chamber may be formed. The initial propellant flow rate for starting purposes is usually less than the flow rate for sustained operating purposes. The lesser initial flow rate for starting purposes tends to prevent excessive accumulation of unignited propellant in the combustion chamber.

For starting decomposition of hydrazine in accordance with the practice of the present invention, a portion of the hydrazine from the fuel tank may be introduced into the reaction chamber through the starting fuel line at a pressure of approm'mately 1900 p.s.i. An oxidizer, hypergolically reactive with hydrazine, may be introduced into the combustion chamber in reaction proportions to the hydrazine under a pressure of approximately 250 p.s.i. Upon coming in contact in the combustion chamber, the hydrazine and oxidizer, such as nitrogen tetroxide, react hypergolically and raise the temperature at the exhaust end of the chamber which, when measured by appropriately placed thermocouples, rose from 70 F., ambient temperature to 1730 F. in a period of 20 seconds, and the chamber pressure rose from atmospheric to 265 p.s.i. during this period, as indicated in Table I below.

Table I Fuel Chamber Supply Temp. Manifold Read. time rate press press (of) pressure g.p.m.) (p.s.i.) (p.s.i.) exhaust (p.s.i.)

20 sec 15. 75 265 1, 830 1, 730 360 MAIN FUEL VALVE OPENED As indicated in Table I, at the end of 20 seconds, tie main fuel valve was opened, and fuel was introduced into the reaction chamber through the manifold 24 under a supply pressure of approximately 1755 p.s.i. A very smooth start was obtained, as indicated, and a smooth pressure transition occurred when the main fuel valve was opened for introducing fuel into the reaction chamber from the manifold.

As is evident from the table, the chamber pressure in a transition period of about V5 second after the main fuel valve was opened increased over six times when compared with the chamber pressure existing before the valve was open even though the supply pressure was reduced. The exhaust temperature rose slightly over F. during the transition period, well Within acceptable temperature limits for operation of turbines and the like presently employed for missile and related applications. The chamber pressure to exhaust temperature ratio before the main fuel valve was opened was approximately 1 to 7, whereas, in less than one second after the main fuel valve was opened, the chamber pressure to exhaust temperature ratio was approximately 1 to plus 1.

The effects in the combustion chamber under these transition conditions would crumple the coated catalysts heretofore employed. However, by employing the coil catalysts of the present invention, the transition occurred smoothly and without any deleterious effects on the materials of construction or performance of the generator. The table also indicates that the exhaust temperature remain relatively constant with slight chamber pressure changes over time.

Thus the present invention provides an auxiliary power unit and generator therefore capable of supplying abnormally large quantities of gases for driving ICBM rocket engines components and the like which utilizes a metallic catalyst for the hydrazine fuel disassociation. Additionally, the generator will withstand the vibrations encountered in such applications and has extremely smooth performance in operation over a wide range of flow conditions. Furthermore, stable decomposition occurs in a relatively small and compact unit, as does effective starting without explosive decomposition and sustained running at high flow rates and pressures without pressure fluctuations.

Although various minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such embodiments as reasonably and properly come within the scope of my contribution to the art.

I claim as my invention:

1. A gas generation system adapted for use as a power source for missiles and the like comprising: a pressurizable source of hydrazine; a pressurizable source of an oxidizer hypergolically reactive with hydrazine; a housing defining a hydrazine disassociation chamber having a gas discharge outlet; first conduit means communicating the source of hydrazine with a manifold in said housing; injection means communicating said manifold with said chamber; second conduit means communicating the source of hydrazine with the chamber; third conduit means communicating the source of oxidizer with the chamber; selectively operable valve means for controlling pressurized flow of the oxidizer and hydrazine in the respective third and second conduit means to said chamber whereby a portion of said hydrazine may be introduced into said chamber through said second conduit means and said oxidizer may be introduced into the chamber to initiate hydrazine disassociation hypergolically and, once hydrazine disassociation is established, hydrazine may be introduced through said first conduit means and said manifold into said chamber; means for selectively controlling operation of said valve means and operative to cut-off the supply of oxidizer after hydrazine disassociation is established; and non-reactive metal coil hydrazine disassociation catalyzers in said disassociation chamber for catalytically maintaining hydrazine disassociation after said disassociation is hypergolically established.

2. A gas generation system adapted for use as an auxiliary power source for missiles and the like comprising: a pressurizable source of hydrazine; a pressurizable source of an oxidizer hypergolically reactive with hydrazine; a housing defining a hydrazine disassociation chamber having a gas discharge outlet; first conduit means communicating the oxidizer source with the chamber; first hydrazine conduit means communicating the hydrazine source with the chamber; second hydrazine conduit means communicating the source of hydrazine with a housing manifold; injection means communicating the chamber with the manifold; selectively operable valve means for controlling pressurized flow of the oxidizer and hydrazine to said chamber through said oxidizer conduit and said first hydrazine conduit to initiate hydrazine disassociation hypergolically in the chamber; valve means for controlling pressurized flow of hydrazine through said second hydrazine conduit for maintaining hydrazine disassociation in said chamber; means for selectively controlling said valve means and operative to cut-off the supply of oxidizer after hydrazine disassociation is established; perforated means in said chamber separating the chamber into three zones and non-reactive metal coil hydrazine disassociation catalyzers in the intermediate zone for catalytically maintaining hydrazine disassociation once said disassociation is established hypergolically. 3. The method of generating gases from hydrazine fuels comprising: introducing hydrazine under a pressure of approximately 1900 p.s.i. into a chamber having nonreactive metal coil catalysts retained therein and which is in communication with a gas discharge outlet, introducing an oxidizer which is hypergolically reactive with hydrazine into the chamber under a pressure of approximately 250 p.s.i., continuing introduction of said oxidizer and hydrazine into the chamber under said pressures for approximately 20 seconds to hypergolically establish hydrazine disassociation conditions therein, thereafter discontinuing introduction of the oxidizer while continuing to introduce hydrazine under a pressure within a range of from approximately 1665 p.s.i. to 1755 p.s.i. into the chamber whereby hydrazine disassociation is maintained catalytically by contact of the hydrazine with said non reactive metal coil catalysts.

4. The method of generating gases from hydrazine fuels comprising:

introducing hydrazine and an oxidizer hypergolically reactive therewith into a chamber for a sufficient length of time to establish hydrazine disassociation conditions in said chamber, discontinuing introduction of the oxidizer and supplying additional hydrazine to said chamber at a maximum flow rate of approximately 89 g.p.m., contacting said additional hydrazine with a non-reactive metal coil catalyst to catalytically maintain hydrazine disassociation, and maintaining a chamber pressure above 1000 p.s.i.

References Cited in the file of this patent UNITED STATES PATENTS 2,004,865 Grison June 11, 1935 2,433,943 Zwicky Jan. 6, 1948 2,573,471 Malina Oct. 30, 1951 2,852,916 Hearn et al Sept. 23, 1958 2,925,709 Mantell et a1. Feb. 23, 1960 2,930,184 Plescia Mar. 29, 1960 2,935,846 Neale et a1 May 10, 1960 2,938,330 Kolfenbach et al May 31, 1960 2,955,423 Perle Oct. 11, 1960 FOREIGN PATENTS 1,042,673 France June 10, 1953 OTHER REFERENCES Rocket Encyclopedia Illustrated, Aero Publishers, Inc., Los Angeles 26, California, pub. April 28, 1959, pages 210-213.

Claims (1)

1. A GAS GENERATION SYSTEM ADAPTED FOR USE AS A POWER SOURCE FOR MISSILES AND THE LIKE COMPRISING: A PRESSURIZABLE SOURCE OF HYDRAZINE; A PRESSURIZABLE SOURCE OF AN OXIDIZER HYPERGOLICALLY REACTIVE WITH HYDRAZINE; A HOUSING DEFINING A HYDRAZINE DISASSOCIATION CHAMBER HAVING A GAS DISCHARGE OUTLET; FIRST CONDUIT MEANS COMMUNICATING THE SOURCE OF HYDRAZINE WITH A MANIFOLD IN SAID HOUSING; INJECTION MEANS COMMUNICATING SAID MANIFOLD WITH SAID CHAMBER; SECOND CONDUIT MEANS COMMUNICATING THE SOURCE OF HYDRAZINE WITH THE CHAMBER; THIRD CONDUIT MEANS COMMUNICATING THE SOURCE OF OXIDIZER WITH THE CHAMBER; SECOND CONDUIT MEANS COMMUNICATING THE SOURCE OF HYDRAZINE WITH THE CHAMBER; THIRD CONDUIT MEANS COMMUNICATING THE SOURCE OF OXIDIZER WITH THE CHAMBER; SELECTIVELY OPERABLE VALVE MEANS FOR CONTROLLING PRESSURIZED FLOW OF THE OXIDIZER AND HYDRAZINE IN THE RESPECTIVE THIRD AND SECOND CONDUIT MEANS TO SAID CHAMBER WHEREBY A PORTION OF SAID HYDRAZINE MAY BE INTRODUCED INTO SAID CHAMBER THROUGH SAID SECOND CONDUIT MEANS AND SAID OXIDIZER MAY BE INTRODUCED INTO THE CHAMBER TO INITIATE HYDRAZINE DISASSOCIATION HYPERGOLICALLY AND, ONCE HYDRAZINE DISASSOCIATION IS ESTABLISHED, HYDRAZINE MAY BE INTRODUCED THROUGH SAID FIRST CONDUIT MEANS AND SAID MANIFOLD INTO SAID CHAMBER; MEANS FOR SELECTIVELY CONTROLLING OPERATION OF SAID VALVE MEANS AND OPERATIVE TO CUT-OFF THE SUPPLY OF OXIDIZER AFTER HYDRAZINE DISASSOCIATION IS ESTABLISHED; AND NON-REACTIVE METAL COIL HYDRAZINE DISASSOCIATION CATALYZERS IN SAID DISASSOCIATION CHAMBER FOR CATALYTICALLY MAINTAINING HYDRAZINE DISASSOCIATION AFTER SAID DISASSOCIATION IS HYRPERGOLICALLY ESTABLISHED.

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