nasa report - air launching manned spacecraft - x-20 dyna soar

8/14/2019 NASA Report - Air Launching Manned Spacecraft - X-20 Dyna Soar

1/38

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

TECHNICAL MEMORANDUM x-636PRELIMINARY PERFORMANCE APJALYSIS OF A I R LAUNCHING

MANNED ORBITAL VEHICLES*By Donald R . Bellman and Harold P. Washington

SUMMARY

A pre l imina ry performance a na lys i s w a s made t o determine t heca pa bi l i ty of l a r ge subsonic and supersonic bombers fo r a i r l aunchingmanned hypersonic and sa t e l l i t e ve hic les . The bombers consid ered nowe x i s t o r a r e b e i n g d ev el op ed i n t h e U nite d S t a t e s . F ou r b o o s t e rc o n f i g u r a t i o ns w er e u se d i n t h e c a l c u l a t io n s , wi th a winged r eh ic l e o ft h e Dyna-Soar ty pe as t h e payl oad . Comparisons were made on t h e b a s i sof vacuum sp ec i f ic impulse , burnout veloci ty , r a t i o of payload weightt o l aunch -package g ro s s we igh t, and s t r uc t u ra l w e i gh t.

The st ud y showed th a t bo os te r packages weighing no more th an200,000 pounds a r e capab le of acce l e ra t i ng a 10,000-pound wingedv e h i c l e t o o r b i t a l v e l o c i t y a f t e r b e in g l au nc he d e a st wa rd f rom asubsonic bomber, i f a vacuum sp e c if ic impulse of ab out 335 seconds canbe ach ieved i n t h e boos t e r eng i nes .

It w a s a l s o f ou nd t h a t a 1-pe rcen t va r i a t i o n i n vacuum s pe c i f i cimpulse from a nominal value of 320 seconds r e s u l t s i n app rox i m a te l y a1-pe rcen t v a r i a t i o n i n bu rnou t ve l oc i ty ; w he reas, n i n c re a s e t o6 pe rcen t i n t he r a t i o of pay load we ight t o l aunch -package g ros s w e igh tfrom a nominal value of 5 pe rcent dec rea se s t h e bu rnou t ve l oc i t y by1,400 f e e t p e r s e co nd .

I t w a s de te rmi ned a l s o t h a t t h e h igh d rag o f t h e boos t e r packager e q u i r e d t o f i t t h e super son i c- l aunch a i rp l an e o f f se t s t h e per fo rmanceadvan t age o f l aunch i ng supe r son i ca l l y r a t he r t h an subso n i ca l l y .


2/38

2

INTRODU CT ION

The use of winged recover ab le v eh ic l es p ro pe l l e d by e f f i c i en t a i r -brea th ing engines as f i r s t - s t a g e b o o s te r s f o r hy pe rs on ic and s a t e l l i t eveh ic l es has cons ider ab le mer i t , rang ing f rom reduced boo s te r cos t whena l a rg e number of l aunches a r e t o be made t o incr ease d ope ra t io na lv e r s a t i l i t y .sounding rocke t s has been f requent ly advoca ted . A d i scuss i on of t h etechnique i s p r e s e nt e d i n r e f e r e n c e s 1 and 2. Launching a body in to anear th orb i t by such means was proposed i n 1956 by A . C . Robott i , whobased h i s ca l cu l a t i ons on an F-102 a i r p l a n e ( r e f . 3 ) . A i r launching i sa l s o the ob jec t i ve of th e more recen t P ro j ec t Ca leb , conducted by th eU . S . N a v y , i n which F4D and F4H air pl an es a r e used ( r e f . 4 ) .

The use of t h i s technique f o r launching upper-atmosphere

For many yea rs th e ai r- lau nch ing techniqu e was used t o l aunch t heX - 1 , X - 2 , and D-558-11 a i r c r a f t a nd i s now bein g used wit h th e X - 1 5r e sea rch a i rp l ane s . The r e su l t a n t ga i n s i n per fo rm ance and ope ra t i ona lsaf e ty have been appre c iab le . To a i r - l aunch manned sa t e l l i t e veh i c l e s ,however, w i l l re qu ir e much g r ea te r launch-package weight . Some an al ys tsh av e p ro po se d t h e c o n s t r u c t i o n of l a r g e , s p e c i a l l y b u i l t a i r p l a n e sp r o p e ll e d b y t u r b o j e t a nd ra m -j e t e n gi n es f o r b o o s ti n g s a t e l l i t e v e h i c l e sof such s i z e th a t the y could be manned ( r e f s . 5 and 6 ) .enormous c os t and th e t ime t h a t would be req ui r ed t o develop such a i r -planes , i t i s b e l i e v e d ex p ed i en t t o e x p lo r e t h e c a p a b i l i t i e s o f t h elarger bombers t h a t now e x i s t o r a r e be i ng deve loped i n t h e U n it edS t a t e s .ana l y t i ca l s t udy o f t he per fo rm ance o f s a t e l l i t e veh i c l e s l aunched fromtwo of th es e bombers . Sim i la r s t ud ie s have al s o been made by othe ri n v e s t i g a t o r s ( r e f . 7, f o r exam ple ).

Because of the

P re se nt ed i n t h i s p a pe r a r e t h e r e s u l t s of a pre l i m i na ry

I n the in ve st ig at ic n, most of t he launches were made a t a highsubso nic Mach number; however, t o show the e f f e c t of l aun ch speed anda l t i t u d e a few launches were made a t a Mach number of 3 . A l t i t u d e swere chosen th a t were ap prop r i a t e t o the speed and type of a i r p la nebeing considered.u s i ng fou r d i f f e r en t boos t e r con f i gu ra t i ons . A lt hough a payload weightof 10,000 pounds was u se d f o r most o f t h e c a l c u l a t i o n s , l i g h t e r andheavier weigh ts were a l so inv es t iga ted .

Launch-package weights ranged up t o 200,000 pounds

The laun ch o0 p o


3/38

3

of n i t r og en te t ro x i de and mixed hydrazine fue l as t h e p r o p e l l a n t . Aran ge of vacuum s p e c i f i c impulse from 300 seconds t o 34 0 seconds wascho sen i n o r d e r t o c o ve r t h e p r a c t i c a l v a l u e s of t h i s p r o p e l l a n t combi-na t i on and t o show th e e f f e c t of vacuum sp e ci f ic impulse on vehic leperformance .

Calculations were made a t t h e NASA F l i g h t Research Center, Edwards,C a l i f .c o n s id e r e d t h e c u r v a tu r e of t h e e a r t h , bu t n o t t h e e a r t h ' s r o t a t i o n .

An IBM 650 d i g i t a l computer was used wi th a program t h a t

SYMBOLS

ax l o n g i t u d i n a l a c c e l e r a t io n , g unitsCD d r a g c o e f f i c i e n t , b a se d on a r e f e r e n c e a r e a of 330 sq f t

l i f t - c o e f f i c i e n t v a r i a t i o n w it h a n gl e of a t t a c kCLaD d ra g, l bF t h r u s t , lbggv

2l o c a l a c c e le r a t i o n of g r a v i ty , f t / s e cc e n t r i p e a l a c c e l e r a t i o n , f t s c2

h a l t i t u d e , f t1; r a t e of change o f a l t i tu d e wi th time , f t / s e c

vacuum s p e c i f i c impulse, secI PL l i f t , lbM Mach number

P ambient p res sure , lb / s q f tq dynamic p r e s s u r e , l b / s q f tr r a d i u s o f t h e e a r t h , f tS t o t a l wing a r e a , sq f tt t ime , sec


4/38

4

CONFIGURATIONS

I f a l aunch veh ic le -boos te r -pay load package, u t i l i z i n g a p r e s c r i b e d .payload and an ex is ti n g bomber, i s t o b e compat ible , var io us modif i -ca t io ns t o the bomber w i l l be nece ssary and th e boos ter must be designedt o f i t both the bomber and t h e payload. With launch-package weig htsapproaching those of th e l aunch veh ic le , pos i t i on i ng o f the cen t e r o fg r a v i t y i s very important , and, because th e payload w i l l be manned,a c c e s s t o the cockp i t i s h i g h l y d e s i r a b l e . These fac to rs have beencons idered i n t h i s s t u d y . A n a r t i s t ' s concept ion of a subsonic bombercar ryi ng one of th e payload-b ooster combinations i s shown i n f i g u r e 1.

Pay1oadThe pay load used i n t h i s s tudy was a winged ve hi cl e of t he D y n a -

A l i f t i n goa r type, having an assumed wing area of 330 square f e e t .payload was s e l e c t e d b e ca u se i t r e p r e s e n te d t h e more d i f f i c u l t b o o s t e r -design problem.mass r a t i o as a r e s u l t o f l e s s demanding s tab i l i z ing- f in requ i rements .

A n o n l i f t i n g p a ylo ad would hav e s l i g h t l y g r e a t e rper fo rmance ca pa b i l i t y because of reduced d rag and inc reas ed p ro pe l lan t

~

v v e l o c i t y , f t / s e c2ir

nvW veh ic le we ight , l ba ang le o f a t t a ck , deg7 f l i g h t -path angle, degi.P a tmospher ic dens i ty , s lug s /cu f tSubscr ip t s :0 s e a - l e v e l c o n d i t i o nbo burnoutvac vacuum

ra te of change of ve lo ci ty wit h t i m e , f t / s e cin c re m e n ta l change i n v e lo c i t y , f t / s e c

r a t e of change of f l i gh t- pa th angl e with t i m e , deg/sec


5/38

5For most of th e ca l cu l a t i on s a payload weighing 10,000 pounds wasA f e w c a lc u la ti o n s were made using 5,000-pound and 15,000-poundsed .

pay loads t o de t e rm i ne t h e e f f ec t o f payl oad w e i gh t.

BoostersThe fou r ba s i c boos t e r con f i gu ra t i ons u sed t o pe r fo rm t he ca l cu -

l a t i o n s are des i gna t ed as t ypes A, B, C , and D . V ar i a t i ons o f t heb o o s t e r s are i n d i c a t e d by numer ica l subs cr ip t s , f o r example A1.i c a l d a t a on t h e b o o s te r s are p re se nt ed i n t a b l e I.e qu ip pe d w i t h s u f f i c i e n t f i n area t o make t he booste r-paylo ad combi-n a t io n n e u t r a l l y s t a b l e a t launch. All o f th e f i n s were cons ideredf i x e d , s i n c e i t was assumed t h a t a j e t a t t i t u d e - c o n t r o l s ys te m was i no p e r a t i o n a t l aunch .

Phys-Each booster was

A drawing of t he ty pe A b o o s te r s w it h f i n s a t t ac h e d i s shown i nf i g u r e 2 .t h r e e s i m u lt a n e ou s l y f i r i n g r o c k e t e n g in e s of 100,000 pounds vacuumt h r u s t e a c h .

These boosters were assumed t o be s i n g l e s t a g e a n d t o have

The type B b o o s t e r s were of th e two-stage tandem typ e, as shown i nf i g u r e 3. These boos te rs used th r ee engines , two dur ing the f i r s ts t a ge and th e remain ing one fo r second-s t age o pera t ion .th ree engines produced a vacuum thrust of l50,OOO pounds.

Each of the

F i gu re 4 a n d f i g u r e 5 show the type C and type D boos t e r con f i gu -ra t i o ns , r e sp ec t i v e l y . These con f i gu ra t i ons were a l so equipped wi thf i n s t o make t h e v e h i cl e n e u t r a l l y s t a b l e a t l aunch .r a t i o n s u s e d t h r e e e n g i n e s , two during the f i r s t - s t a g e o p e r a ti o n andthe remain ing one for second-stage oper at ion . Each engine of bo thcon f i gu ra t i ons p roduced a vacuum thrust of l50,OOO pounds.of t he pay load d i f fe re d between th e type C and type D c o n f i g u r a t i o n .Fo r t he t ype C conf igu ra t ion , t h e pay load was placed ahead of thec l u s t e r of b o o s t e r s ; f o r t h e t yp e D con f i gu ra t i on , t he pay load wasp l aced on t op o f t h e boos t e r c l u s t e r .

Both configu-

Placement

B ecause o f t he s pe c i f i c con f igu ra t i ons o f t he l aunch a i r p l a ne ss e l e c t e d , t h e A, B, and C t ypes w ou ldbe most s u i t a b l e fo r t he subson ic -l a un c h a i r p l a n e a nd t h e D t ype f o r the supe rson i c- l aunch a i rp l an e .would be poss ibl e , however, t o dev ise a D -type con f i gu ra t i on t h a t cou l dbe u sed w i t h bo t h l aunch a i rp l ane s .t i l i t y f o r a sing le-b oos ter development , b ut dec rea se t h e performanceca pa b i l i t i e s f rom t he subson ic l aunch.

I tThis des ign would inc re ase versa-

Booster volumes were based on the use of ni t rogen te t roxide andmixed hydraz ine f u e l as t h e p r o p e l l a n t .d e n s i t y o f 75 pounds per cub i c foo t . This combination ha s an averageFor most o f t he ca l cu l a t i ons , t he


6/38

6basic booster structure was assumed to be 4 percent of the combinedweight of the structure and the fuel. In a few instances, values of2 percent and 8 ercent were used.additional 6 pounds per square foot.150,000-pound-thrust engines were assumed to weigh 1,250 pounds and1,900 pounds, respectlvely.theoretical vacuum specific impulse of about 330 seconds, with a'+O to 1 expansion nozzle. In the calculations, vacuum specific-impulsevalues of 300 seconds, 320 seconds, and 340 seconds were used to showthe effect of the variable on performance.

The fins were assumed to weigh anThe 100,000-pound-thrust and

The chosen propellant combination has a

Carrier AirplanesNone of the proposed launch packages will fit completely in the

bomb bay of either the subsonic or the supersonic carrier airplane beingconsidered. However, for this study the packages are designed so thatrequired modifications to the carrier airplanes would involve only thelanding gear and nonstructural components of the fuselage and, possibly,strengthening of the attach points.

For most of the launch-package configurations, the landing gear ofthe subsonic-launch airplane would have to be extended and the treadwidened, which would make it impractical to retract the landing gear inflight. In the computations the launch speed and altitude were reducedfrom the normal cruise conditions to account for the increased dragcaused by the launch package and the extended landing gear.

It was assumed that the supersonic-launch airplane would havesufficient excess power to compensate for the added drag of the launchpackage, but streamlined fairings would have to be added.

COMPUTATION METHOD

The trajectories used for this preliminary analytical study werecalculated on an IBM 650 digital computer by using the Runge-Kuttamethod of numerical integration. The equations of motion solvedassumed a nonrotating spherical earth.of motion then are The two-dimensional equations


7/38

7

whereh = V s i n 7

2=

D ur ing t he num er i ca l - i n t eg ra t i on p rocess , t he r equ i r ed va l ues ofp r e s s u r e and de ns i ty were o b ta ined from a se r i e s of cu rve f i t s f o r t h eARDC model atmosphere (ref. 8 ) . Each condit ion was computed by usingan i n t e g ra t i o n i n t e r va l o f 2 s econds f rom launch t o bu rnou t .

P re sen t ed i n f i g u r e s 6 (a ) t o 6(d) are plots of the aerodynamic-d r ag c o e f f i c i e n t s u se d i n t h e c a l c u l a t i o n s f o r t h e v a ri o us c o n fi g u-r a t i o n s .on wind- tunnel re s u l t s f rom refe re nce 9 and a compi la t ion of e mpi r i ca lr e s u l t s f r o m r e f e r e n c e 10.

The elements which made up th es e d rag c o e ff ic ie nt s were based

Values of C b used for t he four l aunch-package con f igu ra t io nsw ere ca l cu l a t ed f rom t heo ry fo r con f i gu ra t i ons s i m i l a r t o t h os e u se d i nt h i s p a pe r . F o r c o n f ig u r a ti o n s A, B, C, and D , t he va l ues o fused were, re sp ec t i ve ly , 0 .0556 deg-l , 0 .0449 deg-l , 0 .0274 deg-l , andcLa0.0375 deg- l .a r e a ( s e e t a b l e I ) and were assumed constant throughout the Machnumber range.

T hese va l ues were based on t he t o t a l l i f t i ng - su r f ace


8/38

8

TRAJXCTORIES AND STAGING

For t he pu rposes o f t h e c a l cu l a t i o ns , i t was assumed that eachcon f i gu ra t i on was l aunched i n t o a h o r i z o n t a l f l i g h t p a t h w i th t h es i m ul taneous i g n i t i on of t he f i r s t - s t a ge boos t e r eng i nes and w i t h anang l e of a t t a ck o f 1.5".s p e c i f i e d t i m e , t hen a z e r o - g t r a j e c t o r y was i nduced and he l d un t i lburnout. The t i m e t o change ang l e o f a t t a ck was cons i de red neg l i g i b l e .The time spent a t an ang l e of a t t a ck of 15" was a d j u st e d t o o b t a inv a r i o us f l i g h t - p a t h a n g l e s a t burnout of th e l a s t s t ag e . The id ea lburnout po in t would be when th e f l ig h t -p a t h angle i s zero and the a l t i -t ude and ve l oc i t y a re t h o s e r e q u ir e d f o r e q u i l i b ri u m g l i d e .

T h i s ang l e o f a t t a ck was h e l d c o n s t a n t f o r a

On t h e veh i c l e s l aunched subso n i ca l l y , t h e f i n s were d ropped a t t h eend of the pu l l -up .on veh i c l e s launched supe r s on i ca l l y , s i nc e f i r s t - s t ag e bu rnou t occu r redsoon a f t e r t h e end of t h e pu l l -up .

F i n s were r e t a i n e d u n t i l t h e f i r s t - s t a g e b ur no ut

A t f i r s t - s t a g e b u r n ou t , t h e f i r s t - s t a g e b o o s t e r s were im me dia te lysepa ra t ed f rom t he veh i c l e , and t he second - st age boos t e r i g n i t e d imme-d i a t e l y and rema ined w i t h t he pay l oad fo r t h e r em ai nde r of t he t r a j e c -t o r y . For t he subso n i ca l l y l aunched veh i c l e s , s t ag i ng occu rred a tdynamic pressures of 50 pounds per square fo o t , o r l e s s . For thesupe r s on i ca l l y l aunched veh i c l e s , s t ag i ng occu rred a t lower dynamicp re s su re s .

F igures 7(a) and 7 ( b ) show t r a j e c t o r i e s f o r t y p i c a l s u b so n ic andsupe r son i c l aunches . F l i g h t -p a t h ang l e , ve l o c i t y , dynamic p re s su re ,a l t i t u d e , and l o n g i t u d i n a l a c c e l e r a t i o n a r e p l o t t e d a g a i n s t t i me .

RESULTS

R esu l ts of t he va r i ous com pu ta ti ons a r e p re sen t ed i n t a b l e I1 andi n f ig u re 8. The t ab l e shows t h e i n t e r po l a t ed va l ues a t which a h o r i -z o n t a l f l i g h t - p a t h a n g le c o i n c i de s w i th b u r n o u t, r a t h e r t h a n t h e e x a c tp o i n t s of t h e c om pu ta tio ns . I n a c t u a l f l i g h t , i t would be necessaryfo r bu rnou t t o occur when t he veh i c l e a l t i t u de i s n e a r t h e e q u i l i b r i u mr e e n t r y p a t h and a l s o when t h e f l i g h t p a t h i s w i t h i n 1" or 2" ofh o r i z o n t a l . A s can be s e en i n f i g u r e s 8(a ) t o 8 ( h ) , t h e s e c o n d it io n sa r e not a lways compat ible . However, adjustm ents of th e bo os te r- th ru stprograming and t h e i n i t i a l f l i g h t - p a t h a n g le can o f t e n produce t h ed e s i r e d r e s u l t s . B ecause of t h e p re l i m in a r y n a t u r e of t h i s i n v e s t i -g a t i o n , o n l y f l i g h t - p a t h - a n g l e v a r i a t i o n s were made. No a t t em p t wasmade t o ad j us t boo s t e r - t h r u s t p rogram ing.


9/38

9

22

-

O r b i t a l v e l o c i t y i s achi eved when t h e r e l a t i v e ve l oc i t y i s about24,600 f e e t per second, assuming an eastward launch from th e la t i tu d e sof t h e s o u th e r n p a r t of t he U n it ed S t a t e s .10,000-pound pay load could reach t h i s o r b i t a l ve loc i ty f rom th e subsonic-launch con di t ion by means of b ooste r c onf igu rat ion s B and C2 ( f i g s . 8 ( c )and 8 ( e ) ) . However, vacuum spe cif ic- imp uls e val ue s of about 335 secondswould be req ui r ed . The supersonic- launch con di t ion reduces the req ui r edvacuum sp e c i f ic impulse t o 305 and 301 seconds f o r B an d C2 bo o st e rc o n f i g u r at i o n s , r e s p e c t i v e l y ( f i g s . 8 ( d ) and S ( f ) ) . I t a l s o p e r m it s t h euse of boos te r conf igura t ion D, but , aga in , a vacuum s p e c if ic impulse of335 seconds i s r e q u i r e d ( f i g . 8 ( h ) ) .advantange of th e sup ersonic l aunch can be l o s t i f i t i s n e c es s a r y t ouse a high-drag conf igura t ion such as type D.

The stu dy showed t h a t a

Thus, i t i s a p p ar e n t t h a t t h e

Although not as s i g n i f i c a n t as o r b i t a l v e l o c i t y , a v e l o c i t y of20,000 f e e t per second i s a va l uab l e r e sea rch goa l . A v e h ic l e a t t a i n i n gspeeds i n t h i s r ange can expe rien ce the maximum he at in g ra t e s of ar e e n t e r in g o r b i t a l v e h i c le .b e a t t a i n e d w i t h a si ng le -s ta ge 150,000-pound bo os te r package, w ith avacuum s p e c if ic impulse o f l e s s than 340 seconds , l aunched subs onica l ly .To avoid dup l i ca t ion of booster -development e f f o r t , a p r a c t i c a l p la nmight be t o c o n s t r u c t a type C b o os te r which i n i t i a l l y w i l l a t t a i nv e l o c i t i e s i n e xc es s of 20,000 f e e t per second, b u t no t o r b i t a l speed .Engine and s t r u c tu r a l improvements or , p oss ibly , a sw i tch t o a supe r -son ic l aunch would permi t fu tur e a t t a inment of o r b i t a l speeds .

F igure 8(b) shows t h a t such a v e l o c i t y can

The vario us booste r conf igura t ions a re compared on th e ba s is ofvacuum s pe c i f i c impulse and burnout v e l oc i ty i n f i gu re 9(a) f o r t h esubson i c launch and i n f i g u re g (b ) for t h e supersonic l aunch . Thesed a t a a re combined i n f i gu re 10, which shows th e incre men tal ve lo c i t yre su l t in g f rom devia t io ns i n vacuum sp ec i f i c impulse f rom a value of320 seconds. A 1-pe rcen t i nc rea se i n vacuum sp ec i f ic impulse r e s u l t si n a bo ut a 1-pe rcen t i nc rea se i n burnout ve l oc i t y ; t he re fo re , a1-second change i n vacuum sp ec i f ic impulse r e s u l t s i n a change of about70 f e e t pe r second in burnout ve loc i ty .

For a subsonic l aunch , burnout ve lo c i t i es o f var ious pay loadweight s wi th a t ype C boos te r a re shown i n f ig ur e 11. The effect onb u rn o ut v e l o c i t y o f v a r i a t i o n s i n t he r a t i o o f p a y lo ad we ig ht t o g r o s sweight was i n v e s t i g a t e d f o r t h e c o nf ig u ra ti on C boos t e r bo t h by va ry i ngthe pay load weight wi th a cons t an t gross weight and by varying the grossweight fo r a constant payload weight . The r e s u l t s are compat ible , asshown i n fi gu re 1 2. Changing th e payload weight by 1 pe rcen t of t h elaunch-package gr os s weight from the nominal v alue of 5 p e r c e n t a f f e c t st h e m a x im u m ve l oc i t y i nv e r s e l y by 1,400 f e e t pe r s econd for t h e t y p e Cboos t e r l aunched subson i ca l l y .


10/38

10

For most o f t h e c ompu tat i ons , t he s t r u c t u r a l w e igh t w a s 4 pe r c e n tof th e combined f u e l and s t r uc tu re we igh t . For th e type A b o o s t e rc onf igu r a t i on , va lue s of 2 percent and 4 pe r c e n t w ere u s ed ; f o r t het y p e C boos t e r , va lue s of 4 percent and 8 percent were used.of t h e v a r i a t i o n s i s shown i n f i g u r e 1 3 . D e cr ea si ng t h e r a t i o o fs t r u c t u r a l we ig ht t o f u e l - p l u s - s t r u c t u r e w ei gh t f rom 4 p e r ce n t t o3 pe r c en t i nc r e a s e s t he bu rnou t ve loc i t y by 750 f e e t pe r s ec ond.c r ea si n g t h i s r a t i o f rom 4 p e r ce n t t o 5 p e r c e n t w i l l de c r e a s e t h e bu rn -o u t v e l o c i t y b y 550 f e e t p e r s eco nd f o r t h e c a s e s c o n s i d er e d .

The e f fec t

I n -

CONCLUSIONS

From a pr e l im in a r y pe rf or ma nc e a n a ly s i s of t h e u s e of la rg e bombera i r p l a n e s t o a i r l aunch manned hypersonic and s a t e l l i t e vehi c le s , i t i sconcluded t h a t :

1. Booster packages weighing no more than 200,000 pounds a r ec a pa b le o f a c c e l e r a t i ng a 10,000-pound winged ve hi c le t o o rb i t a lv e l o c i t y a f t e r being launched eas tward f rom a sub son ic bomber, i f avacuum specific impulse of about 335 seconds can be achieved i n th eb o o s t e r e n g i n es .

2 . For m ost of t h e boo s t e r c o n f igu r a t i o ns s t ud i e d , a d e v i a t i o n o f1 percent i n vacuum specific impulse from a nominal value of 320 secondsr e s u l t s i n a bout a 1 - p er ce n t v a r i a t i o n i n b u rn o ut v e l o c i t y .

3 . I nc r e a s ing t he r a t i o of pay load w e ight t o l aunc h- pa ckage g r o s sweight t o 6 percent f rom a nominal value of 5 p e r c en t d e c r e a s e s t h eb u rn o ut v e l o c i t y b y 1 ,400 f e e t pe r s ec ond f o r t h e t ype C b o o s t e rlaunched subsonica l ly .

4. Con fig ura t ion require ments imposed on t h e bo os te r package byt h e l a unc h a i r p l a ne are a n i m po rt an t c o n s id e r at i o n . I n t h i s s tu d y t h ehigh drag of t he boos t e r package requ i red t o f i t t he s upe r s on i c - l a unc ha i r p l a ne o f f s e t s t he per fo rm ance a dva n t a ge s of l a unch ing s upe r s on i c a l l yr a t h e r t h a n s u b s o n i c a l ly .

F l ight Resea rch Cente r ,Nat ional Aeronaut ics and Space Adminis t ra t ion,

Edwards, Calif ., October 9, 1961.


11/38

11

REFERENCES

1. R O S S , Malcolm D . : Aircraf t Launched Rockets , Par t I . Rockair .Sound ing Ro ckets , Homer E . Newell, J r . , ed., McGraw-Hill Book Co.,I n c . , 1959, pp. 165-180.

2. Kraf f , Lou is , J r . , and Slavin, Robert M . : Aircraf t Launched Rockets ,P a r t 11. Ro cka ire . Sounding Rocket s, Homer E . N e w e l l , J r . , ed. ,McGraw-Hill Book Co., In c . , 1959, pp . 181-189.

3 . R o b o t t i , A u r e l i o C . : S a t e l l i t e Launching From an F-102. Miss i lesand Rockets, vol . 1, no. 2, Nov. 1956, pp. 54, 56, 58.

4. Anon. : Navy's A ir-Launch S a t e l l i t e Program S ta r t s F l i g h t T e s t sUnder "Caleb" Project a t Mugu. Western Av ia ti on , Miss i le andS p a c e I n d u s t r i e s , vol. 40, no. 10, Oct. 1960, pp. 4-5.

5 . Kappus, Peter G . : Air-Breathing Power Pl an ts i n th e Space E r a .Aero/Space Eng., vol . 17, no. 11, Nov. 1958, pp. 62-65, 69.

6. F e r r i , A., Daskim, W . , Feldman, L., and Nucci, L . M . : The Launchingof Space Vehicles by Air-Breathing Li f t in g Stages . Vol . 2 ofVistas i n A s tr o na u ti c s. P a r t I V Y Morton Alperin and HollingsworthF. Gregory, ed s. , Pergamon Pr es s, 1959, pp . 163-173.

7. Bulban, Erwin J . : B-52 Use as Fi rs t -S ta ge Boos te r S tud ied .Aviation Week and Space Technology, vol. 75, no. 9, Aug. 28, 1961,PP* 72, 77.

8. Minzner, R. A., and Ripley, W . S . : The ARDC Model Atmosphere, 1956.A i r Forc e Surveys i n Geophysics No. 86 (AFCRC-TN-56-204), A i rForce Cambridge Res. Center (Bedford, Mass.), Dec. 1956.

9. J o h n s to n , P a t r i c k J . , and Ladson, Ch arl es L . : E x p e r im e n ta l I n v e s t i -g a t i o n of L o n gi tu d in a l S t a t i c S t a b i l i t y of a Glider and 11BoosterConf igura t ions a t Mach Numbers From 1.62 t o 6 .86 . NASA TMX-356,1961.

10. Hoerner, Sigh ard F. : Fluid-Dynamic Drag. Pub. by t h e au th or(148 Busteed D r . , Midland Park, N . J . ) , 1958.


12/38

12

3 W( u . 39 1

r - r - I - I - I - I - I -

9 9n " .- r -


13/38

000000N t - r i 0 W - f+ N c o O f o\r l N N ( u N N0; 4-0;mi ;3-

000000000000000000

t n C - o \ Q O r lCUNNCU r r )Wd S Q"u*;

000 000000000 000000000 000000

r l m a t n t - r n m o 4NN(u N N N N r r ) ( rEo ;f-G-f-&-;;

p:-0 t-9-O m c3.- ?-3 m.-9-000-tnm n t nm t -

a

00

00m0--

H m0000 i fm m m

3000003 N-f 0 f7 ? m m m m w 3000003 Nif 0 ;fr n m m m m m000 000000O N 3 O N 7 i ; f O N - fm m m m m m m m m

wVdVQkM.d

r l4


14/38

1 4 "


15/38

L

ka,-Prn00P

a4cdas


16/38

16


17/38

u100P

cdkPI


18/38

18


19/38

/

a0


20/38

20

4-/

- - - - ----cuT00. 0 0

" 2 3rlxcdka,c,rn00P

9


21/38

21


22/38

22

s!0.d+J5bo.dk08acd0r lxcdke,+I,m00PFI

?

EE+av


23/38

23

X0

8D

>-I I I I I I I0 0 0 0 0 0 0 0 0c)3gooooom u c = M (u


24/38

24IC) c


25/38

25

II I--+00m

00cu

00- 0-


26/38

26

m 000- O N 3PI M M Mv1H o n 0

m000Tf-

x

m0X


27/38

27

00e

I '0" 7 1c)tw-cI:


28/38

28

rn M


29/38

Va,Ln000- O N 3Pi M M MrnH 0 0

X0loM

00m


30/38

I


31/38

rc)0

m I

1 0I 0 cU

cu cuX00 I

4-Y-


32/38

32

f I I ONX Lo0 0 0 0Ln 0 Lo 0rr) rr) cu cu -

4-recL


33/38

>-

33

k0rn

. r i

P$

4-10

VQ,v)I

m


34/38

34

--T\

\

0InM

\

1\, cu -I M rc)

M0X

\

uQ)v,cav)-


35/38

0arc)

0Lnrc)

0d-rc)

0rc)rc)

0Nm

0m-00rr)

0mN03

I I

t-Y-

35


36/38

m21

In In 0


37/38

37

VaJv)1cc

I I


38/38

38

nasa report - air launching manned spacecraft - x-20 dyna soar

Documents