NASA / TM--1998-208498 AIAA-98-3736

Launch Vehicle Performance With Solid Particle

Feed Systems for Atomic Propellants

Bryan Palaszewski

Lewis Research Center, Cleveland, Ohio

Prepared for the

34th Joint Propulsion Conference and Exhibit

cosponsored by AIAA, ASME, SAE, and ASEE

Cleveland, Ohio, July 13-15, 1998

National Aeronautics and

Space Administration

Lewis Research Center

November 1998

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LAUNCH VEHICLE PERFORMANCE WITH SOLID PARTICLE FEED

SYSTEMS FOR ATOMIC PROPELLANTS

Bryan Palaszewski*

National Aeronautics and Space Administration

Lewis Research Center

Cleveland, Ohio 44135

SUMMARY

An analysis of launch vehicle Gross Lifloff Weight (GLOW) using high energy density atomic propellants with

solid particle feed systems was conducted. The analyses covered several propellant combinations, including atoms

of aluminum (Ai), boron (B), carbon (C), and hydrogen (H) stored in a solid cryogenic particle, with a cryogenic

liquid as the carrier fluid. Several different weight percents (wt%) for the liquid carrier were investigated and the

gross lift off weight (GLOW) of the vehicles using the solid particle feed systems were compared with a conventional O2/H 2 propellant vehicle. The potential benefits and effects of feed systems using solid particles in a liquid

cryogenic fluid are discussed.

NOMENCLATURE

A fixed mass scaling parameter, kg

AI aluminum

B boron

B propellant dependent mass scaling parameter, kg/kg Mp

C carbon

GLOW gross lift off weight

H atomic hydrogen

He helium

H 2 molecular hydrogen

Isp specific impulse, s

Mp propellant mass, kg

NLS National Launch System

O/F oxidizer to fuel ratio, or mixture ratio

O., oxygen

wt % weight percent

* AIAA AssociateFellow. Leader. NASA Advanced Fuels.

NASA/TM-1998-208498 I
INTRODUCTION

Newtechnologies inatomisolationandthephysicsofmaterial manipulationhaveledtothediscoveryandsynthesisofmaterialsthatcanbeusedasrocketpropellants(Refs.1through25).Solidcryogenicpropellantsstoring

atomsofAI,B,C,andH,orotheratomicadditives, requireauniquepropulsionsystemdesignwherethefuelsare

storedatliquidhelium(He)temperatures duringgroundhandlingandtlight.Feedingatomicpropellantsfromapropellanttankthroughafeedsystemtoarocketenginewillbeaformidablechallenge.

Thereareveryextensivepotential benefitsforusingatomicpropellants. Figure1showstheGLOWreductions

withatomichydrogenasalaunchvehiclepropellant forseveraltomloadings. WithatomichydrogenatanIsp

valueof 750 seconds, the GLOW can be reduced by 44% over the O2/tt 2 baseline case. The baseline case is the

National Launch System (NLS] with a specific impulse (Isp) of 430 selonds (Ref. 1). The 750 second atomic H lsp

performance level requires a 15-wt% of atomic hydrogen stored in solid H 2. The reduction of the GLOW would

result in a significant reduction of the cost of space launch, simplificati _n of the ground support equipment and reduction in the investment in launch facilities.

This paper provides analyses of the rocket engine performance for several atomic propellants, and shows their

effect on the GLOW of an Earth to Orbit rocket transportation vehicle. Several concepts for the formation, storage,

and transport (i.e., feed systems) for atomic propellants are discussed. Also, analyses of the effects of using solid

particle feed systems, and the challenges that must be overcome are pr_ sented.

WHY HEDM PROPELLAN FS?

The overarching vision for HEDM is to create a propellant combination that has at least the performance of

O2/H 2 (typical of the Space Shuttle. which delivers a specific impulse of 452 seconds, in vacuum) but with a higher

overall propellant density. The goal is to reduce the vehicle GLOW, simplify vehicle ground operations, and ultimately reduce the cost of space access. Atomic propellants can theoretically offer an extremely high specific impulse over O2/H 2 propellants. The high-energy atomic propellant must be formulated very meticulously because

they do not occur readily in nature. (Ref. 12, Collins). The atoms in the propellant must be stored in a stabilizing

medium, such as a cryogenic solid, so as to inhibit or delay their recombination into molecules. Atomic propellants

theoretically deliver very high specific impulse as the atoms recombine, release large amounts of energy, and heat

the surrounding medium that is used to stabilize the atoms. Using these propellants is more complex than traditional

propellants because of their unique chemistry and atomic interactions. Next generation RLV propulsion systems

could perhaps use these propellants consisting of atoms in frozen hydrc,gen particles, within a cryogenic liquid carrier, such as helium (Ref. 10).

VEHICLE DESIGNS AND FEED SYSTEMS

Calculations of rocket engine performance conducted in the past (l',ef. I and 11) have considered the atomic

hydrogen and other atoms that are stabilized in a solid cryogenic mater al, such as hydrogen. This solid, however, is

not easily ted though a conventional feed system. Previous propulsion :_tudies have considered either a monolithic

solid containing the atoms, or a segmented solid, much like the concep_ of a throttleable or controllable solid rocket

motor, with preprogrammed pulse elements, each separated by an inhil-itor layer. While this may be a viable approach is some cases, the potential for the atoms remaining in a cryogenic atomic state is questionable. As the grain

is exposed to the combustion environment, it's temperature goes up quickly, and the ability of the remaining propellant to remain in the atomic state drops dramatically. Isolation of the remaining propellant is needed to have the propellant remain in the atomic state at very low cryogenic temperature, where its energy is not released prematurely. A

very light weight inhibitor, or other method of propellant conditioning a,ould be needed. A premature release of the

atom recombination energy will result in extremely high thrust, high a_ celeration, or explosion of the vehicle.

Solid particle feed systems can alleviate the problems of a monolit lic solid fuel grain. The analyses presented

here illustrate the possible designs for launch vehicles using these feed systems. A two-stage vehicle was analyzed

with the solid particle feed systems. Comparisons of the NLS design and GLOW (Ref. 1. 10) with the analyses of

two-stage atomic AI. B. C, and H rockets was conducted. These comparisons will show the effects of the solid

N ASA/TM- 1998-208498 2
particlefeedsystemsonGLOWofthevehicles. Thevehiclemassisestimatedusingthetraditional masscaling

relation:

Mdry=A+B"Mp

where:

Mdry

A

B

Mp

vehicle dry mass, kg

fixed mass scaling parameter, kg

propellant dependent mass scaling parameter, kg/kg Mp

propellant mass, kg

Each of these parameters was estimated with detailed tank mass estimation codes, and scaling from existing

detailed designs (Ref. 10). The addition of He was also modeled, and all of the mass scaling equations are provided

in Tables 1 through 4. The tank maximum operating pressure was 50 psia, the rocket engines used a 30 psia chamber

pressure, and we assumed the propellant is pressure fed. In the mission analysis |or the atomic rockets, the total

velocity change (delta -V) was 9,700 m/s. which is more than 500 m/s higher than the delta-V for the NLS design.

This additional delta-V should accommodate any performance losses or altitude compensation losses incurred with

the lower engine chamber pressure. The vehicle diameter was 6. I meters, and the tankage was cylindrical, with ellipsoidal dome ends.

A slurry or gel of solid hydrogen in liquid helium was considered to control the flow of the atom-solid particle

propellants. The CET rocket performance code (Ref. 26) was used to estimate the effects on Isp for the addition of

He as a carrier fluid. In general, the effcct of the He on the vehicle should be a reduction in the Isp of the rocket, but

there is also an increase in the propellant density, in some cases. The lsp drops due to the addition of the inert helium and the density of the propellant increases because the helium is a higher density fluid than the solid hydrogen.

The lsp reduction is addressed in the rocket pertormance section. For the monopropellant atomic hydrogen

rockets, the solid H 2 particles (encapsulating the atomic H) using a 40-wt% liquid helium carrier has a density of

0.091 g/cm 3 for the cases that were investigated. The solid hydrogen with the encapsulated atoms has a density of

0.077 g/cm 3, about 15 percent lower density than the solid hydrogen liquid helium slurry or gel.

Propellant Types

Several different atomic species were analyzed as rocket propellants. The aluminum (AI), boron (B), carbon

(C), and hydrogen (H) atoms were stored (or encapsulated) in solid hydrogen, and a variety of helium mass Ioadings

were used to irivestigate the performance changes due to the helium carrier fluid. In some cases, oxygen was used

as an oxidizer (as a bipropellant), to improve the performance of the atomic A1 rocket propellants. The B. C, and H

propellants typically had very high Isp performance, and the addition of O 2 would not increase the Isp values. Adding O 2 to the B, C, and H fuel was investigated however, as an option to reducing the total mass of atomic propellants needed for the Earth to Orbit mission. Reducing the total amount of atomic propellants needed would simplify

the ground support equipment at the launch site, and the propellant production facility.

Atom Weight Percent

The atom weight percent (wt%) values are the mass of trapped atoms to the total mass of the atoms and the encapsulating solid H 2. The atom wtC_ values were selected based on the several criteria. A 5-mole percent (moleC?/,)

loading in the solid H2 was selected based on past experimental results (Ref. 2). Current research has concluded that

the maximum atom loading that may be possible in the near term is 5-moleqb. The 5-mole% loading is translated to

a wt% in Appendix A.

The 5 mole% cases translate into different atom wt% for each propellant. With atomic hydrogen, the value is

2.5 wt%. Based on CET Isp calculations, there is no Isp increase for this atomic fuel over O2/H 2, thus a higher goal

for atom storage must be set. If the Isp of the rocket is lower than O2/H 2, the GLOW will be increased, and the complexity of the very low temperature cryogenics will not be considered worthwhile investment lk_r a less than attractive lsp value.

N ASA/TM- 1998-208498 3
TheIspperformance fortheatomicmonopropellants ismuchmoreattractiveathigheratomwt%values.With

BandC,theIspperformanceismoreattractive: 689secondsforB(at_,0wt%),and733secondsforC(at60wt%).

AtomicHdeliversanIspvalueof750seconds(at15wt%).AnatomicAIrocketenginewilldeliveralowlspatless

than390seconds(at80wt%),andseemstobeunattractive.

Theremainingcasesthatwereanalyzedincludeitherthetheoretical peakspecificimpulsesofthepropellant

combinations, orIspvalueswheretheGLOWoftheatomicpropellant vehicles was comparable to or lower than the

O2/H 2 vehicle GLOW. Many of these atom loadings are very high: 50 to 60 wt%. While these atom Ioadings are

high compared to the near term practical maximum levels noted earlier (the 5 molar%), they are nonetheless interesting cases, and represent the ultimate goals that should be pursued fol successful use of atomic propellants in

rocket propulsion systems.

Atomic Propellant Densities

The overall density tbr the atomic propellants is computed using the equations in Appendix B. Tables 5 to 20

shows the propellant densities for the combinations used in the analyses. The fuel densities are dependent upon the

mass fraction of atoms stored and the amount of helium carrier fluid used. The densities of the atom-solid H2 combinations (without He) varied from 0.077 g/cm 3 (15-wt% H in H 2, Table 18) to 149.73 g/cm 3 (50-wtC_ AI in H 2,

Table 6). The analyses using a He carrier fluid were conducted with 10, 20, and 40-wt% of He. The 40-wt% He

cases represent a mixture of 70-volume% of the atom-solid (H/H2) combination, with 30-volume% He. This value

was chosen as the maximum value of volume fraction tbr the solid H2 in slush hydrogen used in the National Aerospace Plane (NASP) program (Re(. 27). This 30 volume% of liquid carrier was considered the minimum needed for

the practical flow of slush H,,.

ATOMIC PROPELLANT ENGINE PERFORMANCE

Several values of wte/,,:of stored atoms are used in the simulations, and the lower values represent wte/c judged

to be possible with near term technology. A 5 mole% value of atoms st,_red in a solid H 2 is considered technically

feasible in the near term. The mole% is translated to wt% values for th_s analysis. Table A I (Appendix A) shows

the near term practical values of mole¢?_ versus wtCh, for the four propeliants. It will be shown later that to reduce

launch vehicle GLOW. much higher values of atom storage will be required.

Tables 5 through 20 show the Isp performance degradation for using a helium carrier fluid to feed the panicles

to the recombination chamber. The heats of formation used in the CET code for the various atoms are listed in Appendix C. In the cases with low atom mass fractions in the solid H 2 (10 to 15 wt%), the influence of the He is strong,

and it significantly reduced Isp performance. At higher atom Ioadings ( _0 wt%), the performance degradation is

much lower, with a much reduced effect. The reduced Isp is also accorr partied by an increase in propellant density

with the atomic H. This density increase is also evident with B and C, f,)r their low atom wt% cases: 22 and 24 wt%

respectively. At the higher atom wt% values, the density decreases as the He is added. All of the engines operated at

a 30 psia chamber pressure with a 60:1 expansion ratio. A 95% engine efficiency on Isp was assumed.

Propellant Mixture Ratios (C/F)

In addition to estimating the rocket lsp for the atomic propellants a _monopropellants, the bipropellant Isp pertbrmance (with O_ as the oxidizer) was computed for several cases. Th,_'se data were generated to illustrate the potential for reducing GLOW by using a higher density oxidizer, rather than a pure monopropellant. Also, if a

bipropellant had an attractive performance level, then the production ol the atomic fuel could be significantly reduced, thereby simplifying rocket launch operations and reducing the c_)st and extent of atomic fuel production.

The lsp performances for the atomic fuels with O 2 were also compated with the three levels of He addition: 10,

20 and 40 wt_.. These data were also used in the selection of the O/F f_ r the bipropellant cases, as the addition of He

did have a strong effect on engine Isp.

NASA/TM- 1998-208498 4
Atomic Aluminum

The predicted performance for aluminum is fairly low compared to O21H 2. As shown in Figure 2, the peak Isp is

390 s, significantly lower than the 430 s Isp for the O2/H 2 case. In the engine pertbrmance analyses, it was found

that atomic A! Isp values were significantly increased with the use of 02 as an oxidizer. With 0 2 as an oxidizer, the

Isp values increase and the maximal value is 507 s at an O/F of 0.5, and a 60 wt% of atomic AI. The atoms of aluminum have a high molecular weight (MW), and hence the addition of O 2 reduces the exhaust MW and increases Isp.

The Isp performance is still fairly low, however, and was dropped from consideration after pertorming some GLOW

analyses.

Atomic Boron

Boron performance is high, over 600 seconds for many cases. Figure 3 shows the map of Isp values. A peak

monopropellant performance of 689 seconds is delivered at a 60-wt% of B atoms. At a 50-wtC_ atom loading, the

Isp value was 651 s. Adding 02 as an oxidizer did not increase the 50- and 60-wt% atomic B Isp over the monopropellant cases.

At 22-wtC_, the Isp does increase with the addition of 02. In Figure 4, the addition of He to the propellant (at an

atom loading of 22-wt%) showed that a peak Isp value occurs at an O/F of 0.5. The monopropellant Isp, sans He.

was 436 s, whereas with an O/F at 0.5, the Isp ranged from 530 s (10-wt% He) to 473 s (40-wt% He). Figure 5

shows the effect of He with a 50-wt%: B cases. At this high atom loading, the He has only a small effect on the

rocket Isp.

Atomic Carbon

The atomic carbon engine performance is also very high, and it's Isp values were 696 seconds for the 50-wtC_

atomic C case, and 733 s for the 60-wt% case, as shown in Figure 6. As with the atomic B, adding 02 as an oxidizer

will not increase Isp for the high atom wt% cases. The monopropellant performance at a 24-wt% level was 513 s.

Figures 7 and 8 show the influence of He on the atomic C Isp at 24- and 50-wt%, respectively. In the 24-wt%

atomic C case, the addition of O 2, in general, decreased engine Isp. At an O/F of 1.0, the Isp is 504 s (10-wt% He) to

471 (40-wt% He). At this O/F value, the Isp reduction due to the addition of He is relatively small compared to

other O/F values. This design point may be worth investigating in future launch vehicle optimizations.

Atomic Hydrogen

The performance with atomic H was the highest of any of the cases investigated. It's lsp values range from 600

to nearly 1300 s. In Figure 9, the highest monopropellant performance is 1500 seconds delivered at a 100-wt% of H

atoms. It's unlikely that we will be able to store 100-wt% of atomic H, so the lower levels of 10, 15, and 50-wtC_

were investigated in the GLOW analyses. Adding 02 as an oxidizer will not increase Isp.

Figure 10 shows the monopropellant performance for atomic H with both equilibrium and frozen flow. There is

a potential for the high wt c&atomic hydrogen engine cases to act as a frozen flow, instead of an equilibrium flow.

Additional analyses of the combustion assuming frozen flow could be conducted, and the reduction in rocket Isp

assessed. All of the analyses presented in this paper use equilibrium flow results, and hence may be optimistic for

the high atom wt% cases.

The effect of He on Isp was computed for the 10-wt% and the 50-wt% atomic H cases, and is shown in

Figures I I and 12, respectively. In the 10-wte/c case, the addition of He always reduced Isp, but the Isp influence

seemed smallest at the O/F value of 1.0. As with the atomic C cases, these O/F analyses may be useful in future

launch vehicle optimization. With the 50-wtC_ case, the addition of He reduced the Isp, but its effect was relatively

small compared to the 10-wt% case.

NASA/TM- 1998-208498 5
GLOW RESULTS AND COMPARISONS

In Figures 13 through 16, the GLOW values of the four atomic propellant launch vehicles are presented. In

most cases, the minimum wt% atomic propellant cases (corresponding _o 5-mole%) did not produce Isp values high

enough to allow a GLOW reduction over O2/H 2 technology. Several higher atom storage cases were run to determine the minimum Isp needed for allowing a GLOW reduction. The cases included the atom stored in H 2 as a

monopropellant and some cases with 02 as an oxidizer. Additional cases were run to investigate the effect of helium addition at the 10, 20, and 40-wt% levels.

Atomic Aluminum

The cases with atomic AI are very poor performers when compared with O2/H 2 technology. As a monopropellant, all of the predicted specific impulse values were 390 seconds. Using 02 as an oxidizer does improve the overall

perlormance level, to nearly 493 to 507 s Isp, but the overall additional mass for the tankage and structure does not

allow the vehicle to deliver a GLOW reduction. Figure 13 shows the GLOW comparison for atomic AI with O2/H 2.

Even with the high 493. I second Isp value (using an O/F of 0.5, and 50-wt% atomic A1), the vehicle GLOW was

still greater than the O2/H 2 vehicle by 27%. Because of its poor performance, this propellant type was dropped from

further consideration.

Atomic Boron

Atomic B has a very good chance of reducing the GLOW of the vehicle when compared with O2/H 2 propellants. The only drawback is that the B atom wt% must be 50 or 60 percent, which is more than double the 22 wt%

value. The 22-wt% cases produced a GLOW of 4.85 times that of O2/Iq2 vehicle. Using a value of 50 and 60-wtC_

B, the GLOW was reduced significantly: by 40 and 50% respectively

Helium addition had a powerful effect in increasing the GLOW. Figure 14 shows the sensitivity of GLOW to

helium addition, with the 22, 50, and 60-wt% B atom cases. The 60 wt% cases were least affected, but the 22 wt%

cases produce unusually large GLOW values: up to 43.5 times the GLOW of the O2/H2 case. Clearly the 22-wt%

cases will not be attractive for this application. With the 50-wt% cases, the addition of 10-wtC_ He does not severely

affect the vehicle GLOW, but as the He goes up to 40-wtC_, the vehicle GLOW is higher than thc O2/H 2 case.

Atomic Carbon

The monopropellant atomic C cases at the 50 and 60-wt% levels h:td reduced GLOW values over the O2/H 2

baseline. However, a 24-wt% atomic C case did not produce a GLOW reduction. The GLOW increase for the

monopropellant case with no He was 74%.

Figure 15 presents the GLOW results for atomic C. The atomic C _ases produced generally higher Isp values

that the atomic B cases, and so their predicted GLOW values were less affected by the addition of He. Both the 50

and 60-wte,_ cases were able to deliver GLOW reductions even alter adding the 40-wt% He.

Atomic Hydrogen

Figure t6 illustrates the GLOW values for atomic H. With atomic -I, no GLOW reductions were possible until a

15-wt_ of atoms were used. At the 10-wt% H level, the atomic H GLI)W was 4% greater than the O2/H 2 baseline.

At a 15-wt% level, the GLOW is reduced by 44%. With a 50-wt% atom loading, the GLOW is reduced by 78%.

When adding He to the flow for the 10-wt% Atomic H cases, the (,LOW is 22% to 106% higher than the

baseline case. as shown in Figure 16. The 15-wt% atomic H cases only exceed the baseline GLOW when the He is

at a 40-wte_ , level. The range of GLOW reduction for the 15-wt% cases was from 37% (with 10-wt% He addition) to

a GLOW increase of 6% with the 40-wt% He added. The 50-wt% atomic H cases are almost unaffected by the He

addition. The GLOW reduction is 72_)_ over the O2/H 2 vehicle GLOW, even with the 40-wt% He addition.

NASA/TM- 1998-208498 6
DISCUSSIONANDOBSERVATIONS

AtomicBdemonstrated veryhighperformanceandgoodGLOWreductionsoverO2/H2,butonlyif thestored

atomvaluesareabove50-wt%.AtomicCalsodemonstrated excellent performanceandabilitytoreduceGLOW

overO2/H2vehicles.AswiththeatomicBcases, thehighestGLOWreductionsarepossibleatthehigheratomwt%

levels:50-and60-wt_.Thehigheratomloadingsdemonstrated agoodinsensitivityoHeaddition,whichwillbe

important foranyvehicleusingacryogenicsolidparticlefeedsystemata4Ktemperature.

WithatomicHata10-wt%level,noGLOWreductionsoverO2/H2vehicleswerepossible. At15-wt%atomic

H,therewereverysignificantGLOWreductions, lorallbutthe40-wt%Headditioncase.The50-wt%atomcases

showedastronginsensitivitytoHeaddition.

Masssummaries ofthepromisingatomicCandHvehicleshowingtheirsubsystemmassesforeachoftheirtwo

stagesareprovidedinTables2I,and22,respectively. TheatomicCvehicleuseda50-wt%atomloading,andthe

atomicHvehicleuseda15-wt%atomloading,andnoHeaddition.Themasseslorthesubsystems aregenerally

conservativeespeciallythestructural masses, whicharetypically7percent of thepropellant mass.A20%contingencymassisaddedtothedryweightsofthevehiclesaswell.Thiscontingencylevelisconservative, basedonpast

preliminaryspacevehicledesignrules,andit accommodates manydesignunknowns. Thedelta-Vusedforthevehiclesizingisalsoconservative, atover9,700m/sforthetriptolowEarthorbit.Thishigherthanusualdelta-V

valuecanalsoaccommodate manydesignunknownsinbothdrymassandengineperformance.

Veryfewcombustiontestshavebeenconductedwithatomicpropellants, andthereforeit'sdifficulttopredict

theexactcombustionefficiency. Insuchahighenergyrocketengine,it willbedifficulttoextractalloftheenergy

notedinthepredictedrocketengineIsp.Enginefficiencysensitivitystudiesshouldbeconductedonallofthecases

inthispaper.

TheselectionofH2asthesolidcryogenforatomstorageisverylikely.Hydrogenisanexcellentrocketpropellant,andcanaddsignificant energyduetotheatomrecombination, aswellascombustion. Othersolidcryogensthat

havebeenconsideredaresolidneonandargon.Thesesolidshavebeenusedinatomstorageexperiments, andmay

beviablecandidates issomeground-based applications. Theirlowercombustionenergiesandhighermolecular

weightsdonotmakethemasattractiveasH2,butfurtherinvestigations arewarranted, if highertemperaturestorage

ofatomsbecomesdesirable.

Theengineandvehiclefficiencyisalsomoststronglyinfluencedbytheabilitytoflowthe4-Ktemperature

fueltoa2000-K(orhighertemperature) engine,whilepreventingprematureatomrecombination. Theheattransfer

betweenthefeedsystemcomponents, theengine,andthepropellant willcreateamajorengineeringchallenge. Duringthetransferofthe4-Katom-solidhydrogen-heliumslurryorgel,thetemperatureofthefuelmustnotvarymore

thanafewdegrees. Theatomswillbegintorecombineif thesolidhydrogensoftens. Additionally, theenginewillbe

quitehot- about2000Ktemperatureintherecombination -combustionchamberfortheatomichydrogencases.

Maintainingtheintegrityofthefrozenhydrogenwiththetrappedatomswillbedifficult,tosaytheleast.Specialized

insulationtechniques, orothersynergisticcoolingtechniques, tolowertheheatfluxtothefeedsystemwillnodoubt

havetobedeveloped. Heattransferinvestigations willbeneededtocreateauniqueandeffectivehighlyintegrated

engineandfeedsystemdesign.

CONCLUSIONS

AtomicBandChadsignificant increasesinIspoverO2/H2.WithBandC,theIspperformancewas689secondsforB(at60wt%),and733secondsforC(at60wt%).AtomicHdeliversanIspvalueof750seconds

(at15wtCh).AnatomicA1rocketenginewilldeliveralowlspatlessthan390seconds(at80wtC_).ThislowIsp

doesnotreducethevehicleGLOW,andthereforeatomicA1seemstobeanunattractivepropellant.

AtomicHdeliversthathighestpossibleIspincreases, butthepropellant mustbestoredatleasta15-wtf_level

todeliverasignificant GLOWreductionoverO2/H2.

Several valuesofwt%ofstoredatomswereinvestigated, andthelowestvaluesnotedrepresent thewt%judged

tobepossiblewithneartermtechnology. A5moleC/cvalueofatomstoredinasolidcryogen, suchasH2,isconsideredtechnicallyfeasibleinthenearterm.However, todeliverareductionivehicleGLOW.muchhighervaluesof

atomstoragewillberequired.

TheGLOWoflaunchvehiclesusingatomicB,C,andHwassignificantlyreducedoverthatforO2/H2propellants.AtomicBreducedGLOWby12to50'_//ata60-wlc/catomlevel.AtomicCallowedGLOWreductionsof8to

NASA/TM-1998-208498 7
48%(ata50-wt%level)andatomicHthepredictedGLOWsavingsisupto44%ata15-wt%atomlevel,andupto

78%witha50-wt%ofatomstorage.Adding He to the fuel to create a gel or slurry with the solid H 2 particles does

reduce rocket lsp, but the overall effect is small at the highest atom wt% values.

CONCLUDING REMARKS

Atomic A1 did not have any significant performance increase over OJH._, and hence the GLOW for these vehicles was very high. The atomic A1 cases were not investigated extens:vely,-but their performance may prove useful

in very high density applications.

Helium addition to the atomic fuels reduced performance, but the performance effects were very small for high

atom mass fractions: above 60 wt%. At the lower atom loadings of 50-wt%, the He addition has a sizable effect, but

the atomic vehicle GLOW was still lower than or comparable to the O2/H 2 vehicle GLOW. Methods of flowing

solid H 2 particles with small wte_ values of He will therefore be desirable.

Additional analyses can be conducted for atomic AI, B, H, and C, carried in solid hydrogen with liquid helium.

In some cases, the density of the combination of atoms and the solid hydrogen may be overestimated, as it is unknown as to what are the exact interactions of the atoms and the solid H 2 once the atoms are stored in the H 2. Therefore, in addition to the using the densities noted for atomic AI, B, and C, a worst-case lowest density assumption of

0.077 from 3 atomic fuel density can be assumed for the different propellants.

Stored atoms in solid hydrogen are the penultimate step in the development of higher pertbrmance, higher density propellants. Future vehicle and engine designs using atom-based propellants have the potential to deliver sizable performance improvements over traditional chemical propulsion systems, as well as commercial benefits

(Ref. 29). Commercial aspects of the propellants are being addressed in current research programs. The advanced

propellants will require longer development times, so they will take a k_nger time to be commercialized than more

traditional propellants. Elements that are related to the propellant feed system technology might be commercialized

in the near future. Near term prospects related to these high energy species might be in the following areas: production methods of the atoms or species, the cryogenic feed system components, superinsulation, valves, flow control

and flow measurement components, feed lines, cryogenic storage, and leak detection systems.

Atomic propellants, such as B, C, and H, have an enormous potential for high lsp operation, and their pursuit

has been a topic of great interest for decades. Recent and continuing advances in the understanding of matter, and

the development of new technologies of simulating matter at it's most basic level, and manipulating matter through

micro- and nanotechnology will no doubt create a bright and exciting ft_ture for atomic propellants.

NASA/TM- 1998-208498 8
AppendixA--Specificimpulsesfor5-mole%

atomcases

Table A I.--Weight_ values for 5-mole% of atoms in

solid H.

Atmn Weight% Monopropellant

(for 5-nloleg_) Isp (s)

AI 41.0 less than 400*

B 22.0 436

C 24.O 513

H 2.6 less than 400*

Expansion ratio = 6/): 1. Chamber pressure = 30 psia.

*Performance not calculated by CET. as the exit

temperature is too low to complete the calculation.

Appendix B--Propellant Densities

The overall density for the atomic propellants is computed using the equations below.

Density = I

Or if helium is added:

( (t- M:,,,,,/density solid H.) + (M,,,,m/density of atom) )

= I

( (I-Mu,,-M hJdensity solid H:) + (M,,.,/density of atom) + (MhJdensity of He)

Where:

M,,,H _ = Atom wtC_ /100

Mh,. = He wt%/100

Density of solid H2 = 0.077 g/cm _

Density of liquid He = 0.125 g/cm _

Density of atoms:

Aluminunl 2.700 g/cm

Boron 2.340 g/cm _

Carbon 1.800 g/cm

H_cdro_cn 0.077 _/cm

Appendix C--CET Heat of Formation Input Data

Table C I.IHeat of Formation for fuel components-All

components at 4 K. except O_. at 90 K

Component

AI atom

B atom

C alom

H atom

H_ Is)

He II)

O_ (1)

Heat of formation (cal/mole)

;'78,800.0

_'135,000.0

" 171,3(X) O

:'52,2(X) 0

:'-2.210.0

_-1.477.8

_-3,102.0

"Ref. 1 I.

bRef. 28.

' Ref. 26.

NASAfI'M- 1998-208498 9
REFERENCES

I. Palaszewski, B.:"AtomicHydrogenPropellants: Historical Perspe_tivesandFuturePossibilities,"NASA

LewisResearchCenter,AIAA93-0244,presentedatthe31stAIAA Aerospace Science Meeting, Reno, NV,

January !1-14, 1993.

2. Carrick, P.. and Tam, S., Editors: "Proceedings of the High Energy Density Materials (HEDM) Contractors'

Conference held 4-7 June 1995 in Woods Hole, MA," USAF Phillips Laboratory, Report Number PL-TR-95-

3039, January 1996.

3. Thompson, T.L., and Rodgers, S.L., Editors: "Proceedings of the High Energy Density Materials (HEDM) Contractors' Conference held 5-7 June 1994 in Crystal Bay, NV," USAF Phillips Laboratory, Report Number

PL-TR-94-3036, December 1994.

4. Thompson, T.L., Editor: "Proceedings of the High Energy Density Materials (HEDM) Contractors' Conference

held 6-8 June 1993 in Woods Hole, MA," USAF Phillips Laboratory, Report Number PL-TR-93-3041,

November 1993.

5. Berman, M., Editor: "Proceedings of the High Energy Density Materials (HEDM) Contractors' Conference held

5-7 June 1992 in Crystal Bay, NV," Air Force Office of Scientific Research, November 1992.

6. Thompson, T.L.. Editor: "Proceedings of the High Energy Density Materials (HEDM) Contractors" Conference

held 24-27 February 1991 in Albuquerque, NM," USAF Phillips Laboratory, Report Number PL-TR-91-

3003, October 199 I.

7. Davis, L., and Wodarczyk, F., Editors: "Proceedings of the High Energy Density Materials (HEDM) Contractors' Conference, 25-28 February 1990, Long Beach, CA," Air Force Office of Scientific Research, May

1990.

8. Wiley, T.G, and van Opinjnen, R.A., Editors: "Proceedings of the High Energy Density Materials (HEDM)

Contractors' Conference held 12-15 March 1989 in New Orleans,., LA," USAF Astronautics Laboratory

(AFSC), Report Number AL-CP-89-002, July 1989.

9. Davis, L., and Wodarczyk, F., Editors: "Proceedings of the High Energy Density Materials (HEDM) Contractors' Conference, 28 February-2 March 1988, Newport Beach, CA," Air Force Office of Scientific Research,

May 27, 1988.

10. Palaszewski, B.: "'Atomic Hydrogen As A Launch Vehicle Propellant," NASA-Lewis Research Center, AIAA

90-0715, presented at the 28th AIAA Aerospace Science Meeting, Reno, NV, January 8-I 1, 1990.

I I. Carrick, P.: "'Specific Impulse Calculations of High Energy Densit3 Solid Cryogenic Rocket Propellants, 1:

Atoms in Solid Hydrogen," USAF Phillips Laboratory Report PL TR-93-3014, April 1993.

12. Collins, G., et al.: "Triggered Energy Releases in Solid Hydrogen Hosts Containing Unpaired Atoms," Physical

Review Letters, Vol. 65, No. 4, pp. 444--447, July 23, 1990.

13. Lee, T.J., and Rice, J.E.: "Theoretical Characterization Of Tetrahedral N4," Journal of Chemical Physics,

Vol. 94, Jan. 15, 1991, pp. 1215-1221.

14. Segal, C., Friedauer, M.J., Udaykumar, H.S., Shyy, W., and Marchand, A.P.: "Ignition Characteristics Of A

New High-Energy Density Fuel In High-Speed Flows," Journal of Propulsion and Power, Vol. 13, No. 2,

Mar.-Apr. 1997, pp. 246-249.

15. Seidl, E.T., Schaefer, H.F., 111, "Theoretical Studies Of Oxygen Rings_Cyclotetraoxygen, (O4)," Journal of

Chemical Physics, Vol. 88, June I, 1988, pp. 7043-7049.

16. Gordon, E.B., et al.: "Metastable Impurity-Helium Solid Phase: Ex _erimental and Theoretical Evidence,"

Chemical Physics, Vol. 170, (1993), pp. 411-426.

17. Scharf, D., et al.: "Nature of Lithium Trapping Sites in the Quantum Solids Para-Hydrogen and OrthoDeuterium," Journal of Chemical Physics, Vol. 99, No. I !, December 1993, pp. 9013-9020.

18. Eaton, P., Or, Y., and Branca. S.:"Pentaprismane," Journal of the Amelican Chemical SocieO', Vol. 103 (1981),

pp. 2134-2136.

19. Matsunaga, N. and Gordon, S.: "Stabilities and Energetics of lnorg mic Benzene Isomers: Prismanes,'" Journal

_[the American Chemical Society, Vol. 166, (1994), pp. 11407- 1419.

20. Lauderdale, W., Stanton, J., Bartlett, R.: "Stability and Energetics _.f Metastable Molecules: Tetraazatetrahedrane (N4), Hexaazabenzene (N6), and Octaazacubane (N8)," Joutvtal of Physical Chemisto', Vol. 96,

(1992), pp. 1173-1178.

2 I. Watts, J.D. and Bartlett, R.J.: "'Coupled-cluster calculations on the C2 molecule and the C2(+) and C2(-) molecular ions," Journal of Chemical Physics, Vol. 96, April 15, 1!_92, pp. 6073-6084.

N ASA/TM- 1998-2(18498 10
22.Fajardo, M.E.,"LimitationsOnStoredEnergyDensitiesInSystemsOfSeparatedIonicSpecies, "Journal of

Propulsion and Power, Vol. 8, Jan.-Feb. 1992, pp. 30-36.

23. Fajardo, M., Carrick, P., and Kenney, J. III, "Matrix Isolation Spectroscopy Of Metal Atoms Generated By

Laser Ablation. I - The Li/Ar, Li/Kr, And Li/Xe Systems," Journal Of Chemical Physics, Vol. 94, May 1,

199 I, pp. 5812-5825.

24. Brazier, C. and Carrick, P.: "Observation Of Several New Electronic Transitions Of The B2 Molecule," Journal Of Chemical Physics, Vol. 96, No. 12, June 15, 1992, pp. 8684-8690.

25. Palaszewski, B., Ianovski, L., and Carrick, P.: "Propellant Technologies: A Persuasive Wave of Future Propulsion Benefits," presented at the 3rd International Symposium on Space Propulsion, Beijing, China,

August 11-13, 1997.

26. McBride, B. and Gordon, S.: "Computer Program for Calculation of Complex Chemical Equilibrium Compositions and Applications. Part 1: Analysis," NASA RP-131 I, October 1994.

27. Hardy, T.: "FLUSH: A Tool for the Design of Slush Hydrogen Flow," NASA TM-102467, February 1990.

28. McCarty, R.: "Thermophysical Properties of Helium-4 from 4 to 3000 R with Pressures to 15000 psia," National Bureau of Standards (NBS) Technical Note 622, NASA CR-128445, September I, 1972.

29. Bushnell, D.: "Far Term Visions: The Frontiers of the Responsibly Imaginable," Transportation Beyond 2000:

Technologies Needed for Engineering Design, pp. 261-295. Feb. 1, 1996.

NASA/TM-1998-208498 I I
TABLE I.--ATOMIC ALUMINUM

MASS SCALING EQUATIONS

He wt% I A, kg I B, kg/kgM_

50 wt% Atomic AI, O/F = 0.50

0 [ 11"5170 I 0.211136

TABLE 2.--ATOMIC BORON MASS

SCALING EQUATIONS

He wt'7, [

22 wick

0

10

20

40

22 wick

(X'I ]

50 wick

o

10

2O

4O

6o

0

10

2O

40

A, kg B, kg/kg Mp

Atomic B, O/F = 0.00

I 1,934.3 0.293811

I 1,934.3 0.293357

I 1,934.3 0.289915

I 1.934.3 0.28302 I

Atomic B. O/F = 0.50

I 1,517.0 0247787

Atomic B. O/F = 0.(X)

I 1,934.3 0.242283

I1.934.3 0.244281

11,934.3 0.246291)

11,934.3 0.250301

wtck Atomic B, O/F = 0.00

11,934.3 0.222803

11,934.3 0.226758

11,934.3 0.230708

11,934.3 0.238616

TABLE 3.--ATOMIC CARBON MASS

SCALING EQUATIONS

He wtck A. kg B. kg/kg Mp

24 wt% Atomic C, O/F = 0.00

0 I 1.934.3 0.293403

10 I 1.934.3 0.290286

20 I 1,934.3 0.287177

40 11.934.3 0.280970

24 wtck Atomic C. O/F = 1.00

00 I 1,934.3 0.221568

51) wick Atomic C, O/F = 0.00

0 I 1,934.3 0.243276

10 I 1,934.3 0.245180

20 I 1,934.3 0.247086

40 11,934.3 0.250895

60 wt_ Atomic C. O/F = t).(_)

0 I 1,934.3 0.223998

10 I 1,934.3 0.227831

20 I 1,934.3 0.231671

41) II ,934.3 0.239328

TABLE 4.--ATOMIC HYDROGEN MASS

SCALING EQUATIONS

He wt% I A, kg B. kg/kg Mp

10 wt% Atomic H, O/F = 0.00

0

_0

tO

1 1,934.3 0.339661

I 1,934.3 0.331936

11,934.3 0.324184

10 I 1,934.3 0.308675

15 wt% Atomic H, O/F = 0.00

0 11,934.3 0.339661

'.0 I 1.934.3 0.331936

20 I 1.934.3 0.324184

40 11,934.3 0.308675

50 wlck Alomic H, O/F = 0.00

(1 11,934.3 11.339661

!0 11,934.3 0.331936

20 I 1.934.3 0.324184

,t0 II ,934.3 0.308675

TABLE 5.--ATOMIC ALUMINUM

ENGINE PERFORMANCE AND

PROPELLANT DENSITY

41 wt% Atomic AI, O/F = 0.5

He wick Fuel density. Isp (s)

_/cm

) 0.1280 n/a

t) 0.1277 454.8

20 0.1274 441.4

_;1) 0.1268 413.3

TABLE 6.--ATOMIC ALUMINUM

ENGINE PERFORMANCE AND

PROPELLANT DENSITY

51) wt% Atomic AI, O/F = 0.5

H_ wlCk

0

10

20

4O

Fuel density, Isp (s)

_/cm

0.1497 493. I

0.1 468 479.9

0.1 440 465,7

0,1388 4.M.0

T,,xBLE 7.--ATOMIC BORON ENGINE

PERFORMANCE AND

PROPELLANT DENSITY

22 wt% Atomic B, O/F = 0.0

H.• wt%

0

10

2O

40

Fuel density, lsp (s)

_:/cm 3

0,1D78 435.5

0.1000 411.7

0.102-3 385.6

0.1071 329.6

NASA/TM- 1998-208498 12
TABLE8.--ATOMICBORONENGINE

PERFORMANCE AND

PROPELLANT DENSITY

50wt%AtomicB,O/F=0.0

Hewt% Fueldensity,lsp (s)

0

10

21)

40

_/cm 3

0.1491 651.2

0.1463 624.7

(1.1436 n/a

0.1384 522.3

TABLE 12.--ATOMIC CARBON ENGINE

PERFORMANCE AND

PROPELLANT DENSITY

24 wt% Atomic C, O/F = 0.0

He wt% Fuel density, g/cm _ Isp (s)

0 0.1000 512.5

I0 0.1020 488.0

20 0.1041 462.11

40 0.1087 41)2.8

TABLE 8,--ATOMIC BORON ENGINE

PERFORMANCE AND

PROPELLANT DENSITY

50 wt% Atomic B, O/F = 0.0

He wt% Fuel density. Isp (s)

_/cm

0 11.1491 651.2

10 0.1463 624.7

20 11.1436 n/a

40 1).1384 522.3

TABLE 13.--ATOMIC CARBON

ENGINE PERFORMANCE AND

PROPELLANT DENSITY

50 wt_ Atomic C. ()IF = 0.1)

He wtCh Fuel density. Isp (s)

:_/cm

0 0.1477 696.3

10 0.1451 668.5

21) 0.1425 638.3

40 0.1377 570.7

TABLE 10.--ATOMIC BORON ENGINE

PERFORMANCE AND

PROPELLANT DENSITY

22 wtCk Atomic B. O/F = 0.5

He wt_

0

10

20

40

Fuel density, lsp (s)

_/cm

0.0978 518.9

0. IIXXI 502.5

0.102,3 485.5

0.1071 449.1

TABLE 14.--ATOMIC CARBON

ENGINE PERFORMANCE AND

PROPELLANT DENSITY

60 wtC_ Atomic C, O/F = 0.0

He wtCk Fuel density, Isp (st

1)

10

20

40

_.]cm x

O.1809 733.4

0.1732 712.2

0.1660 684.5

11.1535 612.5

TABLE 1 I.--ATOMIC BORON ENGINE

PERFORMANCE AND

PROPELLANT DENSITY

511 w'tC_ Atomic B. O/F = I).25

He wtqb Fuel densit]¢, g/cm _ lsp (s)

0 0,1491 632.()

I0 0.1463 614.1

20 0.1436 594.5

411 0.1384 n/a

TABLE 15.--ATOMIC CARBON

ENGINE PERFORMANCE AND

PROPELLANT DENSITY

24 wt% Aton'lic C, O/F = 1.11

He wt% Fuel density.

_/c m

0 0. I(XX)

10 0.1020

20 0.1041

40 0.1087

Isp (sl

487.8

478.2

468.4

447.3

NASA/TM- 1998-208498 13
TABLE16.--ATOMIC CARBON ENGINEPERFORMANCE AND

PROPELLANT DENSITY

50wt%AtomicC,O/F = 0.25

He wtCk Fuel density, Isp (s)

Jcm :_

o O. 1477 644.7

10 0.1451 621.1

20 0.1425 595.9

40 0.1377 539.9

TABLE 17.--ATOMIC HYDROGEN

ENGINE PERFORMANCE AND

PROPELLANT DENSITY

10 wt% Atomic H, O/F = 0.0

He wt% Fuel density, Isp (s)

Jcm _

0 0.0770 611.8

10 0.0801 583.2

20 0.0834 551. I

40 0.0910 rda

TABLE 18.--ATOMIC HYDROGEN

ENGINE PERFORMANCE AND

PROPELLANT DENSITY

15 wit/, Atomic H. O/F = 0.O

He wt'k Fuel density. Isp (s)

_w/cm

0 0.0770 750.0

10 0.0801 713.4

20 0.0834 674.4

40 0.0910 587.6

TABLE 19.--ATOMIC HYDROGEN

ENGINE PERFORMANCE AND

PROPELLANT DENSITY

50 wt% Atomic H, O/F = 0.0

He wt'7, Fuel density, lsp (s)

0

10

20

40

0.0770 1281.5

0.0801 1231. I

0.083,1 I 176.2

0D c)10 1046.0

TABLE 20.--ATOMIC HYDROGEN

ENGINE PERFORMANCE AND

PROPELLANT DENSITY

50 wt_k Atomic H, O/F = 0.25

He wtc/, Fuel density,

JC III ;

0.0770

lsp (s)

o I 156.3

10 0.0801 I 112.4

20 0.08,_.I 1065.0

40 0.0910 954.7

TABLE 2 I.--ATOMIC CARBON

LAUNCH VEHICLE MASS

SUMMARY

Subsystem ] Mass, k_

50 wt% Atomic C, O/F = 0.00

Payload

Fairing

Payload adapter

Stage 2:

lankage

Thermal control

[ngine and feed system

Struclure

Residuals and holdup

( ontingency

Propellant

lnterstage adapter

Stage 1:

I an kage

I hermaI control

Engine and feed system

Structure

Residuals and holdup

Contingency

Propellant

] oral

95,708

7,648

5,441

9,717

9,964

10,0(X)

11,758

2,558

8,799

167,965

17,345

29,012

29,187

I0,(X_0

34,704

7,550

22,091

975.220

FABLE 22.--ATOMIC HYDROGEN

LAUNCH VEHICLE MASS

SUMMARY

50 with , Atomic C, ()IF = 0.00

Payload

Fairing

Payload adapter

Slage 2:

3 ankage

I hermal control

I: ngine and feed system

S _ructure

I, esiduals and holdup

( ontingency

F ropellant

I _terstage adapter

Stage 1:

"1ankage

"1hermal control

I-ngine and feed system

S tructure

I; esiduals and holdup

( ontingency

Propellant

'] oral

95,708

7,648

5,441

18,614

14,247

I 0,000

11.647

2,534

11,408

166,384

18,086

57,465

43,474

10,000

35,737

7,774

30.890

1,057,583

NASA/TM- 1998-208498 14
2000 ]

1soo

1000

o 500 ÷

i

0 4 ....

Atomic hydrogen rockets: no helium addition

Atom wt% = 10 15 50

NLS: H:

Isp Isp

430 s 612 s

_ IDPropulsion

,_[] Payload f

" I ......

H: H:

Isp Isp

750 s 1282

s

Propulsion technology

Figure 1 .--Atomic hydrogen GLOW: monopropellant H/H2, no helium addition.

O/F

Atomic aluminum engine performance: 02 as oxidizer

800

600

400

200

0

o3 o

o_ ¢N o I_

,P. o i_

o o3

o o ,- Atom wt%

Figure Z--Atomic aluminumengineperformance.

m

e_

._o

o

Q.

U_

NASA/TM-1998-208498 15
Atomic boron engine performance: 02 as oxidizer

O/F

800

600

200 g

O.

(/)

e_ 0

o o o Atom wt%

Figure 3.--Atomic boron engine performance.

v

m

.e

O.m

.m

O

O.

U)

600

5OO

400

300

200

100

0

Atomic boron: 22-wt%, with helium

• • | I

I × x x x ! !

x

I"lO-w,% ,eI

x 40-wt% HeJ

0 1 2 :! 4 5

O/F

Figure 4.--Atomic aluminum engine performance.

NASA/TM- 1998-208498 16
A

u)

E

o

u

U)

700

600

500

400 I

300

200

i

100 +

oi

0

Atomic boron: 50-wt%, with helium

x x

o0-wt°ioi_e

• lO-wt% He

• 20-wt% He

x 40-wt% He

1 2 3 4 5

O/F

Figure 5.--Atomic boron engine performance.

Atomic carbon engine performance: 02 as oxidizer

800

,B

400

200

0

¢5 o o_ Atom wt%

O/F o

Figure 6.--Atomic carbon engine performance.

NASA/TM-1998-208498 17
600

.-._ 500

400 "

a.

E

•- a00

o

¢,3

a. 200 -

I

100 !

0

0

Atomic carbon: 24-wt% with helium

" • : ! =

K x

_ x

x

• O-wt% He

• 10-wt% He

i• 20-wt% He

I

x 40-wt% He l .......

1 2 3 4

O/F

Figure7.mAtomic carbon engine Isp:heliumaddition.

A

(n

(n

Q.

E

om

tJ

,'=_

(J

q)

Q.

U)

700

6

600 i

5O0

400

I

300

200

100

0

Atomic carbon: 50-wt%, with helium

x •

x

x K

0-wt% He 1

10-wt% He

20-wt% He

x 40-w1% He i

; 4 I ÷ _

0 1 2 3 4 5

•IF

Figure8,--Atomic carbon engine Isp:heliumaddition.

NASA/TM- 1998-208498 18
Atomic hydrogen engine performance: 02 as oxidizer

.... 0.50 0.25_o

0.00 o o_

O/F

Figure 9.--Atomic hydrogen engine performance.

1600

1200

800

400

o

Q.

.E

._u

o

(D

Q.

U_

2000 7---

1500

G)

B

Q.

.E 1000

,m i

N--

o.. 500 (/_

Atomic hydrogen: without helium

i• Equilibrium ]

i • Frozen ....

0.0 0.2 0.4 0.6 0.8 1.0

Atom wt%

Figure 10.--Atomic hydrogen engine performance.

NASA/TM- 1998-208498 19
A

w

Q.

E

*m

.2

,m

o

(/}

700 =

Atomic hydrogen: 10-wt%, with helium

600

500 t

40O

: : : ! z

X x X X X X_

300 -

200

100

J

0 _

0

* 0-wt% He

• 10-wt% He

• 20-wt% He

x 40-wW= He

1 2 3 4 5

O/F

Figure 11 .--Atomic hydrogen engine Islet helium addition.

A

(R

V

m

E

=m

.2

q,.

*m

O

03

1400 I

1200

1000

i

800

600

400

200

0

Atomic hydrogen: 50-wt%, with helium

× :

X

X

.|

×

I

* 0-wt% He I

i

• 10-wt% He I

I

• 20-wt% He J

× 40-wt%He I

0 1 2 3 4 5

O/F

Figure 12.--Atomic hydrogen engine Isp: helium addition.

NA SA/TM- 1998-208498 20
Atomic aluminum vehicle GLOW

2500

O_

Nm

O

U)

O

O

O

..I

(3

2000

1500

1000 _

50O

0 _

m

NLS Ah Isp 493 s

Propulsion technology

Figure 1 3.mAtomic aluminum vehicle GLOW.

[] Propulsion

[] Payload J

"8

b

o

o

o

..I

(3

10000

80OO

6OOO

40OO

2000

0

NLS

Atomic boron rockets: helium sensitivity

I I

B: 22-wt% B: 50-wt%

Propulsion technology

Figure 14.--Atomic boron vehicle GLOW.

B: 60-wt%

He Added!

O0-wt%

- lO-wt%

• 20-wt%

• 40-wt%

NASA/TM- 1998-208498 21
A

O)

J¢

I

k

O

3:

o

.J

4OO0

3500

3000

2500

2O0O

1_0

1000

500

Atomic carbon rockets: helium sensitivity

0

NLS

I I

C: 24-wt% C: 50-wWo C: 60-wt%

Propulsion technology

Figure 15.--Atomic carbon vehicle GLOW.

He Added

00-wt%

• 10-wt%

• 20-wt%

• 40-wt%

4000

350O

A 30OO

O1

2500

I

0

,.1

1000

50O

0

NLS

Atomic hydrogen rockets: helium sensitivity

I I

H: 10-wt% H: 15-wt% H: 50-wt%

Propulsion technology

Figure 1 6.--Atomic hydrogen ve'_icle GLOW.

i * 00-wt%

,* 10-wt%

. 20-wt%

N ASA/TM- 1998- 208498 22
Form Approved REPORT DOCUMENTATION PAGE

OMB No. 0704-0188

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources,

gathering and maintaining the data needed, and completing and reviewing the collection of information, Send comments regarding this burden estimate or any other aspect of this

collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson

Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to lhe Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503

1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE

November 1998

4. TITLE AND SUBTITLE

Launch Vehicle Performance With Solid Particle Feed Systems

for Atomic Propellants

6. AUTHOR(S)

Bryan Palaszewski

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Lewis Research Center

Cleveland, Ohio 44135-3191

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Washington, DC 20546-0001

3. REPORT TYPE AND DATES COVERED

Technical Memorandum

5. FUNDING NUMBERS

WU-260-98-09_00

8, PERFORMING ORGANIZATION

REPORTNUMBER

E-II294

10. SPONSORING/MONITORING

AGENCY REPORT NUMBER

NASA TM--1998-208498

AIAA-98-3736

11. SUPPLEMENTARY NOTES

Prepared for the 34th Joint Propulsion Conference and Exhibit cosponsored by AIAA, ASME, SAE, and ASEE. Cleveland,

Ohio, July 13-15, 1998. Responsible person, Bryan Palaszewski, organization code 5830, (216) 977-7493.

12a. DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified - Unlimited

Subject Categories: 15 and 20 Distribution: Nonstandard

This publication is available from the NASA Center for AeroSpace Information, (301) 621-0390.

12b. DISTRIBUTION CODE

13. ABSTRACT (Maximum 200 words)

An analysis of launch vehicle Gross Liftoff Weight (GLOW) using high energy density atomic propellants with solid

particle feed systems was conducted. The analyses covered several propellant combinations, including atoms of aluminum (AI), boron (B), carbon (C), and hydrogen (H) stored in a solid cryogenic particle, with a cryogenic liquid as the

carrier fluid. Several different weight percents (wt%) for the liquid carrier were investigated and the gross lift off weight

(GLOW) of the vehicles using the solid particle feed systems were compared with a conventional O2/H 2 propellant

vehicle. The potential benefits and effects of feed systems using solid particles in a liquid cryogenic fluid are discussed.

14. SUBJECT TERMS

Atomic hydrogen; Cryogenic fuels; Feed systems; Rocket propulsion; Slurry propellants:

Gelled propellants

17. SECURITY CLASSIFICATION

OF REPORT

Unclassified

NSN 7540-01-280-5500

18. SECURITY CLASSIFICATION

OF THIS PAGE

Unclassified

19. SECURITY CLASSIFICATION

OF ABSTRACT

Unclassified

15. NUMBER OF PAGES

28

16. PRICE CODE

A03

20. LIMITATION OF ABSTRACT

Standard Form 298 (Rev. 2-89)

Prescribed by ANSI Std. Z39-18

298-102