UN CLA~S”Ifliii LA-4541-MS ‘NJ ‘% Ff
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APPROVED FOR PUBLIC RELEASE ● ☛☛ A b VERIFIED UIVCLAslFIED. UN CLA~S”iFliii LA-4541-MS ‘NJ ‘% ff. /?~y _~— CIC-14 REPORT COLLECTI REPROEXJCTK’N ~; ~ ~- COPY ‘i LOS ALAMOS SCIENTIFIC LABORATORY ~ of the University of California LOS ALAMOS ● NEW MEXICO i VERIFIED UNCLASSWIED Per 7-/0-79 . Nuclear Pulsed Space Propulsion Systems (U) -1 _ UNITED STATES = =U) ATOMIC ENERGY COMMISSION >=_b ma := CONTRACT W-7405 -ENG. 36 “=% kg AEC RESEARCH AND DEVELOPMENT REPORT ~—s=== m _——0 ~~-o ~-ca 3=-m .sSm cJ—-1-—m = m ..-. .—_. 1 ____ .— ~’i . .— APPROVED FOR PUBLIC RELEASE — ● m . APPROVED FOR● PUBLIC● O9 RELEASE● . 9 m. : .’. ● .,* c “.,.:”~’+.: .*!ii.‘ ● * 89m ●&’ ... ~.. ... ‘ :: 0:: .: :. ● ● . :: : ● ::. OQ . .:. : ● 00 , . b This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Atomic Energy Commission, nor any of their employees, nor any of their contrac- tors, subcontractors, or their employees, makes any warranty, expre= or im- plied, or assumes any legal liability or responsibility for the accuracy, com- pleteness or usefulness of any information, apparatus, product or process dis closed, or represents that its use would not infringe privately owned rights. ,. This report expresses the opinions of the author or authors and does not nw- essarily reflect the opinions or viewa of the Los Alamos Scientific Lalmratory. s- ● ☛☛ ● 9* ● 0 9** ● ● ● * ● 9 ● 90 ● 8 ● 0 ● e ● ● ● m ● 0 ●:0 ● *9 ● * ● , ● C: ,,, . :00 :0. i“; ● 00 ● *em ● ● ● *a ● ☛✚ ● ● e ● ** ● e ● m APPROVED FOR PUBLIC RELEASE ., , APPROVED FOR PUBLIC RELEASE .,” ! ‘-”● ● 00 9** .:= :~= :* -u~~~AJJ,; ● *0:000 ..: 9* ● 0:: ,0 .:00 .0 Written: October 1970 ● ..* ● . 900 ba LA-4541-MS C-91, NUCLEAR REACTORS Distributed: November 1970 FOR ROCKET PROPULSION M-3679 (64th Ed.) LOS ALAMOS SCIENTIFIC LABORATORY of the University of California LOS AL.AMOS s NEW MEXICO CtA:SIFICtiTIONCH.’dW~ ‘1’OUNCIA$SIFED BYMJ’I’W=~-f~~4wmGwii.&3 VERIFIEDBY (SIGNA’1’JJRE Nuclear Pulsed Space Propulsion Systems (U) by J. D. Balcomb L. A. Booth C. P. Robinson —— T. P. Cotter T. E. Springer J. C. Hedstrom C. W. Watson UNITED STATES ATOMIC ENERGY COMMISSION .-- —————.—— CONTRACT W-7405 -ENG. 36 ● m ● .* ● 90 ● *9 ● ea ● a - UNCI .ASNFIED APPROVED● **..* FOR PUBLIC● *** RELEASE >, .,. APPROVED FOR PUBLIC RELEASE . ... - ● ☛ ●9: 9** .*. ::..:.:: -~ . b ● . — . .’ ...— k~ . * . .. .. ‘,. .’-—4. :-” ------- ----- ii :O-s O.. ● APPROVED FOR PUBLIC RELEASE APPROVED FOR PUBLIC RELEASE !l!AmaOF (xmENTs . ● Abstract 1 I. Introauctial 1 II. Nucl.cmReactionsfor PulsedPropulsion 3 Fusion 3 Fission 3 LaserInittition of NuclearReactions 3 III. PreliminaryDesignConcepts & Oeneral 4 ConceptA-1, External~stem with PusherPlate 5 ConceptA-2, ExternalSystemwith Magnetic Field and PusherPlate 6 ConceptB, InternslSystem 6 PulseUnit DesignConcepts -i’ DesignDsplicationsof PayloadShielding 8 Iv. MissicuConsiderationsand PerformanceEstimates 9 General 9 scalingIaws 10 OptimizationProcedure IL Comparisonof Externaland ~ternal ~stem Concepts 12 PerformanceLimitatIons u+ PerformanceEstimates 15 Acknowledgments 17 References l-f Appendices A. LaserConceptsand Consideraticms 18 B. Es* Considerationsfor pusher-propellantrnte~ction 20 c. NeutronEnvironmentalConsiderationsfor the ExternalSystem 22 . 0 <-0% ● m ● om ● *O ● *9 ● 9* ● e -MICLAWFIED ‘“ ● .** APPROVED8***** FOR PUBLIC● .** RELEASE APPROVED FOR PUBLIC RELEASE a at end of mission,relativeto the apacecrdt, a Pw3her-plateaccelerat im, n/se# a. 2pacec~ accelention at end of mlssl~, relatiweto an Inertialf’rsms of referunce, m/sec2 b J-, a~--ss 60 Stsntlardacceleraticn of gravity,9B m/eec2 I IIIWIMSdeliveredto the spacecraftby one @se unit,!?-e.ec Im 2pectiichqnil.ee,(1~ = Ve/go),sec in Pulse-unitmass,kg M Totalspacecraftinitialnmas,kg Ma M==n*-absor~r IUSSS(Ma = Me + ~), W Initifil.epacecrz&tpmpeKlaat mass,kg, n pulseunitsof % consisting of m,es Is, (~= nnl) Me Mcmentum-conditionernuss,kg kg Pavbad mass.k. AnY mass not desimated othexvise;Includesstructure (&her than Ma)‘andI&s laserunit, ~Mo = M - Ma - H). pusher~latemass,kg % n Numberof @se units,dimensionless q Pulse-unitenergym=lease,J u InitialvelncityOr the pusherplate ($ustafterthe pulse-unitinteraction) relativeto the spacecraft,m/see Ve EffectiveVelQCitYof the propellantexhaust,m/see Averagevelocityof propellantimpingingagainst *he puslmr-plate ‘i surface,m/see w Materialstrength+8eightconstantdefinedby Eq. (6),m/see Xa Ma/M,dissmaimless xo Me/M,ditu?nsionkss a DiJIIMMkdlSSE efficiency term definedby lul.(5) for fiteti system at Dinb?nslonlesa efficiency term def Inedby ~. (5)for externe3system 9 collimation factor def tied by Eq. (17), dinmaionless At T- Intenral betueen pulse-unit detonatlons$ sec & Relative M.etauce OS travel> or stroke, of the pusher plate relative . to the spm2ecraftj m N Mise%on-aquivalanttie-space velocityclmnge,m/see , T Efficiencyte= deftiedby Eq. (2),dimensionless v Disk?nsbn.lessparamder for en energyscalinglaw, definedby 2q. (8) u’ Dimensionless~ter it&&&@e”&#& ~, definedby lzq.(15) ● .: :* ● . .- ● 9 .* ● em ● m. 9:9 :.. iv ● ✎ 0s0 --- ; -*- -em APPROVED FOR PUBLIC RELEASE APPROVED FOR PUBLIC RELEASE ● ‘@[email protected] ● 00 :00 :a :.* :.O ● ● :.* *:.: : ● *: .:** .0 ● ● ** ● .*. :** ● . NUCIEARPUKED SPACEPROPUWION SYslms w J. D. Balcomb L. A. Booth c. P. Robinson T. P. Cotter T. E. Springer J. C. Hedstrom c. W. Watson AWIRACT Inltislconsiderationsare presentedfor advancedspace-propulsion conceptsthat are basedon ener~ producticn by laser-driventhermonuclear pulses. Preliminarydesignconceptsare comparedin which en individual pulseunit, locatedeitherintemaJJy or externeXlyto the system,Imparts ~ me to the SIX?.cecI’Sf’t.Max?vpulseunits- sequentiallydischarged and initiatedunt11 the desiredspacecraftvelocityis reached. various means Of shockabsorptionand shieldingagainstfast neutronsgeneratedby the therwnuclearreactionsare investigated.Indicationsare that the maximumspecificimpulsefor an internalsystemwould be . 2500 see, whereasthat for an externalsystemmightattain-7500 sec. 1. INTROI.XJCPION g- be- to studythe applicationof such energy pulsesfor spacepropulsion.VariousI.ASLgroups Studiesat Los AlamosSclentfficLaboratory (IASL)and at laboratoriesthroughoutthe world have have initiatedsupportingstudiesand experiments, indicatedthe passibilityof Lnitiating lcw-yield and are particularlyactivein investigationsof thermonuclearreactionsby the use of an intense laser-inducedthe.rnsmucleerreactions. laserpulseto heat to ignitiona very smellpellet The propulsionpotentialof nuclear-pulsedsys- of fusionablematerial. If a cufficientlyh%gh tem- tems is extraordinary:It offersthe possibilityof peratureand densitycan be achiwed in the pellet, approachingthe optimalutilizationof the ultimate thermonuclearreactionswill occurreleasingsub- kncwn sourceof energywith minimaladverseside stantialenergy. Presumably,this energyrelease effects. wouldbe much lower (O.1to 100 equivalenttons of The use of nuclearexplosionsfor propulsionwas TNT) than the minimumpracticalyieldspresently firstproposedby Uleml and has been investigatedin availablefrom fission-implosion systems. Possible detailbetween1958 and 1965 underProjectOrion.* applicationsof such small,cleanenergyreleases IiIthe finalconcept,fiss%onexplosionsof one to includeterrestrialelectricpurergenerationand 12 lcllotons(equivalentm explosiveenergyrelease) the ob~ectof this repoz’t:spacepropulsion. were to be detonatedbehinda spacec~ to accehr- Activitiesat I&L relatedto I.aeer+lriven ate propelMnt materialthatwould impe.rtmomentum thermonuclearreactionshavebeen underway for over to a massivepusherplate;this momentum,in turn, one year, includingthermonuclearburningstudies was to be transmittedmore gradusllyfrom the pusher end laserdevelopment.In J’une1970,the Advanced plateto the spacecraftthrougha pneumaticspring PropulsionConceptstask grcupwas formedwith the Wstem. @ studyWas terminatedbecauseof the in- specificob~ectiveof Investigatingadvancedpropul- herenjhuge sise of the resultingspacecraft(4000 ● 00 sion concepts;as part of this invest~O~i”&~t&’ ~ Uonr$,“becauseof the limitationsimposedby the ● * ● ● 9 9* :: **C ● ● * 9** ● ** ● O* ●:0 ● 0 1 APPROVED FOR PUBLIC RELEASE APPROVED FOR PUBLIC RELEASE ● m b ●*. 3 ‘. ●*: 9:0 ● mm . ● * ● . ● * ● ●: :: ...: -o =**. nucleartest-bantreaty,and becauseof the d~i:”” “%at ~f%&k ~2&eWurt withoutths eknents deterio- cultyOf testingthe system. N was, however,gen- rat*. Nuclear [email protected] pmgmldcm systems are shi- eI’611Yacknowledgedthat the conceptwas techni- 3x@y mites, but, becanseof the extrewdy short C- soundmd mighthave achievedthe vem high interactiontb of the pulses,at much highertem- specificimpulse(1 ) of - sec. Pemtures. The interactiontimes,of the orderof Sp 25m . nKU.iseconde,are simplytoo shortto causemuch The possibilityof producingrmIsIJ.,cleannu- cleare@osions mmmves the two primaxyobstacles destnwtive damage,especiaUy if ablative materials usea to furtherprotectthe expmea surfacesfmm . in the Orionconcept--largesize end spacepollu- are high temperatures. tion. Spacecraftcan now be envisionedthatmay be even smallerthen those curnentlyproposedfor the Although,at present,it is assumedthat the nuclearspaceshuttle,yet be able to greatlyout- genemtlon of laser-driventhernxmucl.e=reactions performeventhat high-performancesystem. @ ap@kable to apacepropulsionis feasible,i.e., systemcan alsobe meenin@iUy testedon or belcw that the largeeffortsat IASL and elsewherewilJ. -d. AMhou6h a laser-drivenpulsedpropulaim yieldthe expectedresults,It