Apollo Experience Report Launch Escape Propulsion Subsystem

8/8/2019 Apollo Experience Report Launch Escape Propulsion Subsystem

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N A S A T E C H N I C A L N O T E N A S A T N D-7083

M000

C,ASE F I LE. COPY

APOLLO EXPERIENCE REPORT -LAUNCH ESCAPE PROPULSION SUBSYSTEMby Neil A , TownsendMunned Spacecrafi CenterHoustotz, Texas 77058N A T I O N A L A E R O N A U T IC S A N D S PA CE A D M I N I S T R A T I O N W A S H I N G T O N , D. C. M A R C H 1973


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1. Report No.NASA TN D-7083

APOLLO EXPERIENCE REPORTLAUNCH ESCAPE PROPULSION SUBSYSTEM

2. Governme nt Accession No. 3. Recipient's Catalog No.

March 19734. Title and Subtitle6. Performing Organization CodeI5. Report Date

7. Authods)N e i l A . Townsend, MSC9. Performing Organization Name and Address

Manned Spacecraft CenterHouston, Texas 77058

8. Performing Organization Report No.MSC S-343

10. Work Unit No.914-11-00-00-7211. Contract or Grant No.

17. Key Words (Suggested by Author(s) 1Apollo Launch Escape PropulsionSolid Rocket MotorsTower Jettison

* Pitch-Control Motor' Launch-Escape Motor

13. Type of Report and Period CoveredTechnical Note2. Sponsoring Agency Name and Address

18. Distribution Statement

National Aeronautics and Space Admini strationWashington, D.C. 20546

19. Security Classif. (of this report) 20 . Security Classif. (of this page) 21 . NO. of PagesNone None 29

14. Sponsoring Agency Code

22 . Price$ 3 .OO

I15. Supplementary NotesThe MSC Director waived the use of the International System of U nits (SI) for thi s ApolloExperience Report because, in hi s judgment, the use of SI Units would impai r the usefu lne ssof the report or result in excessive cost.

16. AbstractThe Apollo launch escap e propulsion subsys tem contained th ree so lid rocke t motor s. Thegen eral design, development , and qualification of the solid-propellant pitch -control, tow er-jett ison , and launch-escape m oto rs of the Apollo launch escap e propulsion subsystem werecompleted during the y ear s 1961 to 1966. The launch escape system components are de-scrib ed in gener al te rm s, and the sequence of events through the ground-based tes t pro gra msand flight-test programs is discussed. The initial ground rul es established for this sy stemwere that it should use existing technology and designs as much as possible. The pract ical-ity of th is decision is proved by the minimum number of probl ems that wer e encounteredduring the development and qualification progr am.


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CONTENTS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. . . . . . . . . . . . . . . . . . . . . . . . . 2P i t c h - C o n t r o l M o t or . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3T o w e r - J e t t i s o n M o t o r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Launch-Escape Moto r . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .N o r m a l L a u n c h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A b o r t C a p a b i l i t ie s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

BASED TE ST PROGRAM . . . . . . . . . . . . . . . . . . . . . . .P i t ch -C on t ro l Moto r Qua l i f ica t ion -T e st P r o g r a m . . . . . . . . . . . . . .T o w e r - J e t t i s o n M o t o r Q u a l i f ic a t io n - T e s t P r o g r a m . . . . . . . . . . . . .Launch-Escape Moto r Qua l i f i ca t i on -Tes t P rog ram . . . . . . . . . . . . .P i t c h - C o n t r o l M o t or Q u a li fi c at io n a nd P r o d u c t io n P r o b l e m s . . . . . . . . .

. . . . . . . .T o w e r - J e t t is o n M o t or Q u a l if ic a ti o n a nd P r o d u c t i o n P r o b l e m sLaunch-Escape Moto r Qua l if i ca ti on and P roduc t i on P r ob l em s . . . . . . . .

PAD-ABORT TEST PROGRAM . . . . . . . . . . . . . . . . . . . . . . . . . .Apollo Pad A b o r t 1 M i s s i o n . . . . . . . . . . . . . . . . . . . . . . . . . .Apollo Pad A b o r t 2 M i s s i o n . . . . . . . . . . . . . . . . . . . . . . . . . .

5

666788991011 '13 ,1313

LITTLE JOE TES T P R OGR AM . . . . . . . . . . . . . . . . . . . . . . . . . . 14ATURN AND AP OL LO UNMANNED FLIGH T-TEST .PROGRAM . . . . . . . . 21ANNED- FLIGH T PROGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

CONCLUDING REMA RKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24iii


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T A B L E S

T a b l eI SE L E CT E D DE SIGN CHARACT E RIST ICS O F L E S MOT ORS . . . . .I1 L IT T L E J OE I1 FL IGHT PROGRAM OBJ E CT IVE S . . . . . . . . . .

(a) LE S l aunch.eh ic le qualif icat on . . . . . . . . . . . . . . . . . .(b) Ap o ll o A-0 01 mi s s i o n t r an s o n i c ab o r t at h i gh d y n am i cp r e s s u r e . . . . . . . . . . . . . . . . . . . . . . . . . . . . .(c ) Apollo A-002 m iss ion abo r t at m a x im u m d y na m ic p r e s s u r e . . .(d) Apol lo A-003 miss ion h igh-a l t i tude abor t . . . . . . . . . . . .(e ) Apol lo A-004 m iss io n ab or t in the power-on tumb l ing. . . . . . . . . . . . . . . . . . . . . . . . .b o u n d a ry r eg i o n

I11 APO L L O L E S QUAL IFICAT ION FL IGHT S . . . . . . . . . . . . . .FIGURE S

F i g u r e1234

Ap ol lo l aun ch e s c ap e s y s t e m . . . . . . . . . . . . . . . . . . . . .Pi t ch -co n t ro l mo t o r . . . . . . . . . . . . . . . . . . . . . . . . . .T o wer - j e t t i s o n mo t o r . . . . . . . . . . . . . . . . . . . . . . . . .L au n ch -e s cap e mo t o r(a) Mo t o r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .(b) Igni ter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

' 567a9

1 0111 2

Ma jor even t s of Apol lo PA-2 m iss io n . . . . . . . . . . . . . . . .Ma jor even t s of Apol lo A-001 m iss io n . . . . . . . . . . . . . . . .Ma jor even t s of Apol lo A-002 m iss ion . . . . . . . . . . . . . . . .Ma jor eve n t s of Apol lo A-003 m iss ion . . . . . . . . . . . . . . . .Ma jor eve n t s of Apol lo A-004 m iss ion . . . . . . . . . . . . . . . .Apol loBP.13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .M ajor ev en t s of Apol lo AS-101 m iss ionM ajor eve nts of Apol lo AS-102 m iss ion

. . . . . . . . . . . . . . .. . . . . . . . . . . . . . .

1 51 61 6i a1 922

P a g e234

56

1 420202020212121

iv


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Page

13 M i s s i o n -ab o r t p o i n ts i n r e l a t i o n t o Sa tu rn lau n ch -v eh ic l ef l igh t enve lope . . . . . . . . . . . . . . . . . . . . . . . . . . .Test r e g i o n an d a b o r t p o i n ts for the Apollo A-004 m iss io n . . . . .

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APOLLO EXPERIENCE REPORTLAUNCH ESCAPE PROPULSION SUBSYSTEM

By Ne i l A . TownsendM a n n e d S p ac e cr af t C e n t e rSU MMAR Y

The Apo l lo l aunch escape p ropu l s ion subsys t em con t a ined t h re e so l i d -p rope l l an troc ke t m o to r s : t he l aunch -escape m o to r , t he t ower - j e tt i son mo to r , and t he p i t ch -con t ro l mo to r . The l aunch -escape mo to r , t he main mo to r in t he l aunch esca pe sys t e m ,had a t h rus t o f 155 000 pounds and wa s capab l e of moving the command module awayfr o m and out of the path of the re ma in ing p or t ions of the launch vehic le i f a l aunch -veh i c l e ma l func t i on occu r red and an abo r t w a s r equ i red . The t ower - j e t t i son -moto rf u nc ti on w a s t o s e p a r a t e t h e l a u nc h e s c a p e s y s te m f r o m t h e c o m m a n d m o d u le b e f o r edep loymen t of t he comm and modu le pa rach u t es if an a b o r t o c c u r r e d . T h e t o w e r-j e tt i so n m o t o r a l s o w a s u s e d t o r e m o v e t h e l au nc h e s c a p e s y s t e m a w ay f r o m a n d ou tof the path of a norm al ly funct ioning launch vehicle . The p i tch- con t ro l mo tor w a se s s e n t i a l t o e s t a b l is h a s a f e t r a j e c t o r y of t h e ac ti va te d la u n ch e s c a p e s y s t e m . T h edes ign , qua l i fi ca t ion , and t e s t i ng of the l aunch escape sy s t em com ponen t s w er e com -p le te d d u r i n g t h e y e a r s 1961 t o 1966 a nd w e r e r e m a r k a b l y free of fai lures .

INTRODUCTIONT h e A p ol lo l a u n ch e s c a p e s y s t e m (LES) as des igned t o p rov ide a p o s i t i v e m e a n sof c r e w e s c a p e if b o o s t e r failure oc cu r re d du r ing t he in i t i a l pha se of launch . Thesy s t e m had t o ach i eve su f f ic i en t a lt i tude fo r dep loymen t of t he com man d modu le (CM)p a r a c h u t e s a nd t o e n s u r e s a f e lateral separa t i on . L a t e r a l s e p a r a t io n w a s a c h ie v ed b yf i r i n g s i m u l ta n e o u s l y th e p i t c h - c o n tr o l m o t o r and t h e l a u n c h - e s c a p e m o t o r f o r l ow -a l t i t ude abo r t s . The p i t ch -con t ro l mo to r w a s not r eq u i re d fo r h igh -a lt i tude ab o r t s .T h e s y s t e m is no l o n g e r r e q u i r e d after second-s tage igni t ion and is j e t t i soned afterve r i f ic a t io n of ign i t ion .The pu rpose o f t h i s r epo r t is to ident ify those p r o b l e m s th a t w e r e e n co u nt er edi n t h e L E S p r o p u ls i on c o m p o n e n ts p r o g r a m . Where pos s ib l e , an exp lana t i on is m a d eof how these p rob l ems migh t be avo ided i n any fu tu re p r og ra m .


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A - ba l l a s s em bly#COMPONENT CONF l GU RAT l ON

T h e p i t c h -c o n t r o l m o t o r , t h e t o w e r -j e t t i son mo to r , and t he l aunch -escapemo to r cons t i t u ted the p ropu l s ion com po-n e n t s of th e L E S, a n d t h e s e m o t o r s p r o -v ided t r a j ec to ry shap ing , LES - j e t t isonc a p a b i l it y , a n d p r i m a r y p r o p u l s io n , re-spect ively . Also , the LES fig. 1) ncludedt h e Q - b a ll a s s e m b l y , t h e l a u n c h - e sc a p et o w e r c a na r d s y s t e m , t h e s t r u c t u r a l s k i r t ,t h e to w e r s t r u c t u r e , t h e t o w e r a n d C Ms e p a r a t io n s y s t e m , t h e f o r w a r d - h e a t -sh i e ld s epara t i on and re t en t i on sys t em,and the boost p ro tec t ive cover . . Selectedd e s i g n c h a r a c t e r i s t i c s of th e LES m o t o r sare given in table I.

Item

1 B a l l as t c om pa r t m en t Cana r d - s uppo r ts t r u c t u r e

rd c P i t c h - c o n t r o l

LE SI31 ft 11 ir

I

T ower - j e t t i s on m o t o r

4 ' t owe r - j e t t i s on mot h r us t - v ec t o r ang le

1 .

I 1 t h r us t - v ec t o r ang le

m o t o rI n t e r s t a g e s t r u c t u r e

\ Launc h - es c ape m o t o r- t r u c t u r a l s k i r tI\l o w e r s t r u c t u r e

F o r wa r d - hea t - s h i e l d -separat ion sys teml o w e r leg (separated byexplod ing bo l t sys tems)

F i g u r e 1. - Apol lo l aunch escape sys t em.TABLE I. - SELECTED DESIGN CHARACTERISTICS O F LES MOTORS

Weight, lbLength, in.Diameter, in.Thrust level at sea -levelpressure, lb

Thrust-ris e time from appli-cation of firing curren t toreach 90 percent of maxi-mum, msec

pressure, lb-secTotal impulse at sea-level

Satisfactory performanceafter uniform soak temp er -atures, OFMaximum, " FMinimum, " F

Pitch-control motor51

22.0010.5154000

.___~-

60 o 120 (to reach80 percent ofmaximum)1750 70" F) (t3per-

cent)c

14020

Tower -jettison motor53555.6228.00

31 200 to 36 000 (140" )'

~~

(average thrust)29 400 o 33 900 (70" F)28 000 o 32 400 (20" F)

75 to 150

(average thrust)(average thru st)

35 900 to 37 700 (140"F)35 800 o 37 600 70 " F)35 700 to 37 500 (20" F)

14020

Launch-escape motor4850185.5753.66

5200 000 (120"F)(maximum vacuumthrust)

b z 1 4 7 000 (70" F)2121 000 (20' F)(minimum thrus t)

50 to 120

515 000 70" F)(minimum)d

12020

aTemperatures in parentheses ar e propellant-grain temperatures .bAverage thrust between 0.12 and 2.0 seconds at a pres sure altitude of 36 000 feet.'Capability af te r modification fro m 1550 o 3000 lb-sec.dMinimum deliv ered t otal impu lse between 0.12 and 2.0 seconds + 233 064 lb-sec.

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P itch-Control MotorT h e co mb u s t i o n ch am b er wa s t h e ma j o r s t ru c t u re o f t h e p i t ch -co n t ro l mo t o r(f ig . 2). T h e o u t s i d e wa l l of t h e co mb u s t i o n ch am b er h ad p ro v i s i o n s fo r mo u n t in g th em o t o r h o r i zo n t a l l y wi th i n t h e can a r d - s u p p o r t en c l o s u re . T h e c o m b u s t io n c h a m b e r h a dt h r e e basic p a r t s : a c y l i n d e r , a f o r w a r d c l o s u r e -d o m e a s s e m b l y , a nd a n aft c l o s u r e -

d o m e a s s e m b l y.

F i g u r e 2. - Pi t ch -co n t ro l mo t o r .

Th e so l id -p rope l l an t g r a in of the p i tch -con t ro l m otor w a s of a 1 4 -p o i n t i n t e rn a l -b u rn i n g star co n f ig u ra t io n . T h e s o l i d -p ro p e l lan t g r a i n ( ap p ro x i ma t e l y 8.9 p o u n ds ) wa sc a s t d i r e c t l y a g a i n s t t h e c o m b u s ti o n c h a m b e r l i n e r s . In t h e o r i g i n a l LES m i s s i o n re-q u i r e m e n t s , it w a s s p e c i fi e d t h a t t h e p i tc h -c o n tr o l m o t o r m u s t be s u i t ab l e fo r mo d i fi -ca t i o n so t h a t a to ta l im puls e of 1550 to 3000 pound-seconds cou ld be prov ided wi thou tm a j o r r e d e s i g n , r e d e v e lo p m e n t , o r requa l i f i ca t ion . The p i t ch -co n t ro l -m otor con-t r a c t o r me t t h i s d e s i g n r eq u i r em en t by v a ry i n g th e p ro p e l lan t -g r a i n l en g th ; t h e ad d it io nof au x i l i a ry m a t e r i a l s s u ch as g r a i n s u p p o r t s o r i n e r t s l i v e r s w a s n ot n e e de d . U l ti -m a t e l y , i n A p oll o m i s s i o n r e q u i r e m e n t s , a t o t a l i mp u l s e of 1 7 5 0 p o u n d - s eco n d s w asp r e s c r i b e d ; t h e r e f o r e , t h e s o l i d -p r o p e ll a n t g r a i n le n gt h w a s a p p r o x im a t e l y 8.2 i n ch es .T h e m ax i mu m s o l i d -p ro p e l lan t g r a i n len g t h t h a t was u sed d u r i n g d ev e l o p men t w asa p p r o x im a t e l y 1 5 . 9 i n c h e s.T h e s o l i d -p ro p e l l an t g r a i n w a s ignited b y mea n s of an i g n i t e r a s s e m b l y t h a t co n -s i s t ed o f a p e l l e t -b a s k e t -t y p e i g n i t e r , t wo p re s s u re t ap s , an d t wo p y ro t ech n i c igniterc a r t r i d g e s . E a c h p y r o te c h n i c i g n i t e r c a r t r i d g e c o n s is te d of a b o o s t e r c h a r g e a n d a nAp o l lo s t an d a rd i n i t ia t o r ( h o t-b r id g ewi re - ty p e i n i t ia t o r ) . T h e p y ro t ech n i c i g n i t e rca r t r i d g e s of t h e p i t ch -co n t ro l m o t o r we re i d en t i ca l t o t h e p y ro t ech n i c i g n i t e r car-t r i d g e s that w er e u s ed i n th e l au n ch -e s cap e mo t o r an d cou l d be in s ta l l ed at the l aunchp ad .

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Tower-Jettison MotorThe t ower - j e t t i son mo to r had two maj o r pa r t s : t he combus ti on ch am ber and t hein t e r s t age s t ruc tu re ( f i g . 3 ) . T h e c o m b u s ti o n c h a m b e r a n d inter stage-structure as-s e m b ly w e r e 26 i n c h e s in d i a m e t e r , were 55.6 inc he s in length , and weighed527 pounds.

5 5 . 6 in .

Combustion- Aft-closure-TH e a d- e nd anachmenl ring /-chamber cylinder

F i g u r e 3 . - Tower - j e t t i son mo to r .The i n t e r s t age s t ruc tu re , des igned and deve loped as a n i n te g r a l p a r t of t h e t o w e r -j e t ti son mo to r , was u s ed t o a t ta c h t h e t o w e r - je t t is o n m o t o r t o t h e l a u n c h - e s c a p e m o t o r .The 90 .3 -pound cy l i nd r i ca l i n t e r s t ag e s t r uc tu re had a d i a m e t e r of 26 i nche s and alength of 30 n c h e s .The two exhaus t nozz l es of t he t ow er - j e t t i son mo to r w er e bo lt ed t o the aft c l o s u r eof the combus t ion cha m be r ( f ig . 3 ) . T h e n o z z l e s w e r e s u b m e r g e d i n t h e c o m b u s ti o nchamber and ex tended through the i n t e r s t a g e s t r u c t u r e w a l l .The so l id-p rope l lan t gra in of the tow er- je t t i son mo tor w as of a 10-poin t , double-web, in ternal -burn ing star conf igurat ion . T h i s com pos i t e so li d -p rope ll an t g ra in , w h ichweighed approximately 205 pounds , was cast d i r e c t l y a g a in s t th e c h a m b e r l i n e r (fig. 3).The so l id -p rope l lan t g r a in d id not r e qu i re t he add it i on o f such aux i l i a ry m at e r i a l asg r a i n s u p po r ts o r i n e r t s l i v e r s t o m e e t t h e d e s i g n o b j ec t iv e s .

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An ign i t e r a s sem bly w as u sed t o i gn i t e t he so l id -p rope l lan t g ra in of the t o w e r -j e t t i son mo to r . The i gn i t e r a s se mb ly cons i s t ed of t he i gn i t e r combus t i on cham ber , t hep res s u re - t a ke -o f f po r t , t h e pe l l e t - con t a ine r a s sem bly , and t he i gn i t e r so l i d -p rope l l an tg r a i n .The main ch ar ge of t he i gn i t e r a s se mb ly , a compos i t e so l i d -p rope l l an t i gn i t e r

gra in , cons i s ted of approximately 1 . 8 3 pounds of the sa m e type of p rope l lan t that wa sused i n t he t ower - j e t t i son mo to r . The p rope l lan t w a s c a s t in a l i ne r t ube t ha t wascom pose d of a p a p e r - b a s e p h e n o l i c r e s i n . The c a s t g r a in w a s i n s e r t e d i n the i g n i t e rca se and w as bonded i n p l ace . The i gn i t e r a s sembly w a s ign i ted by m ea ns of redu ndant(tw0) yro t echn i c i gn i t e r cart i dge s.Launch-Escape Motor

Th e ca se as se m bly of t he l aunch -escape mo tor ( f ig . 4 (a )) w as ma de of hea t -t r ea t ed s t e e l and inc luded a cyl indr ica l mount ing f lange at t h e f o r w a r d e nd f o r u se inmoun t ing t he t ower - j e t t ison mo to r ( f ig . 1). T he aft c l o s u r e d o m e of the l a u n c h - e s c a p emoto r w as made of hea t - t r ea t ed h igh - s tr eng th s t ee l and w as a t t ached t o t he ca se as-sembly by m ea ns of a bo l ted f l ange . The dome con ta ined p rov i s ions fo r a t t achmen tof the fou r fi xed -exhaus t nozz l es , fo r moun ting of t h e m o t o r - c a s e a s s e m b l y , a ndf o r m a t in g of t h e d o m e w i th t he s t r u c t u r a l s k i r t .

F o u r e x ha u st n o z z l e s w e r e s e c u r e d t o t he aft clo su re dom e. Off-s iz ing of ther e s p e c t i v e e x h a u st -n o z z le t h r o a t d i a m e t e r s , as was done on the t ower - j e t t i son mo to re x h a u s t n o z z l e s , p r ov id e d t h e m e a n s f o r e ff e c ti v e t h r u s t - v e c t o r d e f le c ti o n f r o m t h e .m e a n g e o m e t r i c m o t o r c e n t e r l i n e .The so l i d -p rope l l an t g ra in of t he

l aunch-escap e mo to r had an e igh t -po in t,i n t e rna l -bu rn ing star conf igurat ion . Themoto r w as i gn it ed by m ean s of an i g n i t e ra s s e m b l y ( fi g. 4 ( b) ). T h e i g n i t e r a s s e m b l yw a s mounted on the forw ard end of them o t o r - c a s e a s s e m b l y a nd w a s c o n c e n t r icwith the moto r cen t e r l i ne . The igniter as-semb ly con ta ined a b o o s t e r c h a r g e p r o p e l -l a n t c h a r g e a n d a m a i n p r o p e l l a n t c h a r g e .T h e b o o s t e r c h a r g e w a s c om p o s e d of borona n d p o ta s s i u m n i t r a t e ; t h e m a i n p r o p e l l a n tc h a r g e w a s of t h e s a m e t y p e as t he l aunch -e s c a p e m o t o r p r o p e l l a n t .

--- I4igniter-wirecartridge

(a) Motor .F i g u r e 4. - b u n c h - e s c a p e m o t o r .

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I nner post( fiber g l as s1 7

0 50 in ( w a s 0.310 in . )E l - ! I-

PropellantR od (0.435-in. diameter)

grainA

Potting Nozz lelone-piece.phenolic1

(b) Ign i t e r .F i g u r e 4. - Concluded .

O P E R A T I N G MODESN o r m a l L a u n c h

L A

During a no rm al l aunch , j e t t i son of the LES (f ig. 1)w as i n i ti a ted man u a l l y .No rma l l y , t h e to wer - l eg ex p l o si v e b o l t s an d t h e t o wer - j e t t i s o n mo t o r w e r e i g ni teds imul taneous ly . The LE S and the boost p ro tec t ive co ve r w er e pu ll ed ou t of the pa th oft h e o n co min g l au n ch v eh i c l e . T h e l a t e r a l - s ep a ra t i o n man eu v e r en s u red a m i n i m u mm i s s d is ta n c e of 150 feet. F o r wo r s t - ca s e co n d i ti o n s, t h e L E S co ul d s ep a ra t e an davo id recon tac t wi th the l aunch veh ic le . If t h e t o wer - j e t ti s o n mo t o r ma l fu n c t io n ed , t h el au n ch -e s cap e m o t o r co u ld b e u s ed fo r t h e LES j e t t i s o n wi th o u t i mp a i r i n g t h e s a f e t y oft h e c r e w m e n .

Abort C apabi it esThe six t y p e s of a b o r t c a p a b i l i t ie s th a t w e r e c o n s i d e r e d n e c e s s a r y f o r th e L E Sw e r e as fo l lows .Pad escape . - F o r a n a b o r t j u s t b e fo r e o r s h o r t l y a f t e r l if t- of f, t h e L E S w o uldhave separa ted the C M f r o m t h e s e r v i c e m o d ul e (SM) an d t h e lau n ch v eh i c l e . T h e C Mwould have been p rope l led to an adequate he igh t f o r p rop er opera t ion of the CM e a r t hland ing sys te m . Suf f ic i en t ran ge would be o b ta i ned t o mi n i mi ze w i n d -d r i f t p ro b l em s .T h e a b o r t - t r a j ec t o ry p l an e was f i x ed n o mi n a ll y i n a d o wn - ran g e d i r ec t i o n . T h em i n im u m - a lt it u de r e q u i r e m e n t f o r p ad a b o r t s w a s 3000 feet at apogee .

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Low - a l ti t u d e a b o r t . - T h e L E S w a s c a p a b le of s e p a r a t i n g t h e C M f r o m a t h r u s t i n glaunch vehic le at a l t i t u d e s at which range -safety cons ide ra t i ons p roh ib i t ed t e rmina t i onof l aunch -veh i c l e boos t e r -eng ine t h r us t ; t ha t is, unt i l approximately 40 s e c o n d s a f t e rl i f t -off .A b o rt a t h ig h dy n a m i c p r e s s u r e . - The LE S had t he capab i l i t y t o func ti on at t h e

m a x i m u m d y n a m i c p r e s s u r e t h a t w a s e x p e c te d d ur in g la u n c h . T h e a b o r t w o uld bei n i t i a ted be fo re s t r uc tu r a l b reaku p of t he l aunch veh i c le .Abor t be low 10 0 000 feet a l t i t ude . - T r a n s i ti o n a l t i tu d e w a s a p p r o x i m a t e ly100 000 feet. An abor t cou ld be i n i ti a t ed e i t he r manua ll y o r au tomat i ca l l y by m ean sof a n e l e c t r i ca l s i gna l t ha t o r i g ina t ed f ro m the l aunch -veh i cl e em erge ncy de t ec t i onsyste 'm. If a n a b o r t s i g n a l o c c u r r e d , t h e l a u nc h - e sc a p e m o t o r , p i t c h -c o n t r o l m o t o r ,and C M-to -SM t ens ion - t i e p y ro t e chn i cs wou ld be i gn i ted s imu l t aneou s ly . The p i t ch -con t ro l mo to r and t he l aunch -escape mo to r would p rov ide t h ru s t fo r app rox im ate ly

0.6 and 4 . 0 s ec onds , r e spe c t i ve ly . The p i t ch -con t ro l mo to r cou ld p roduce a l a r g ep i tch ing momen t of r e l a t i ve ly s ho r t du ra t i sn . The l a rg e p it ch ing mom en t would i n -c r e a s e t h e r a n g e c a p a b il it y f o r p a d a b o r t s a nd would i n c r e a s e lateral s e p a r a t io n f r o mthe f l igh tpath of the launch vehic le- f o r a b o r t s at h igher a l t i t udes . A t 42 s e c o n d s a f t e rl i ft -of f, the p i tch- con t ro l m oto r would be deac t i va ted , e i t he r au tomat i ca l l y by a t i m e r -c o n t r o ll e d r e l a y o r m a n u a l ly b y a c r e w m a n - o p e r a t e d s w i t c h .Subsequent to an 11 . 0 - second de l ay a f t e r abo r t i n i ti a t ion , t he can ar ds would bedep loyed t o r eo r i en t a t e t he L ES and t he CM in t he hea t - sh i e ld - fo rwa rd a t t it ude . Then ,after a 3 . 0 - s e c o n d d e l a y , o r after d e s c e n t t o an alti tude of 25 000 feet, t he LES and t hedock ing mech an i sm wou ld be j e t t i soned by me an s of s i m ul ta ne ou s igni tion of the tow er-j e t t i son mo to r , t he LES tower - l eg exp los ive bo l t s , and t he dock ing -mechan i sm py ro -t echn i cs . The boos t p ro t ec t i ve cov er , wh ich is a t tached t o t he L ES tower s t ru c tu re ,would be j e t t i soned wi th the LES.Abor t above t r ans i t i on a l t i t ude . - A t a l t it u d e s g r e a t e r t h a n 1 0 0 000 feet, t h e c r e w -men wou ld use t h e r e ac t i on con t ro l sy s t em of t he C M to p rov ide a pos i t ive p i tch ingmo men t fo r t he LES and CM. The can ar ds would be dep loyed 11 s e c o n d s after a b o r ti n i ti a t ion , and subsequ en t eve n t s wou ld be s im i l a r t o those de sc r ibe d i n t he p reced in gp a r a g r a p h .M a x i m um a b o r t a l ti t u d e . - T h e m a x im u m a lt it ud e f o r a n L E S a b o r t w a s c o m p a t i b lewi th the com plet ion of l aunch-ve hic le second-s tag e igni t ion , wi th the sep ara t ion ofj e t ti soned componen t s , w i th t he ach i evem en t of a l a u nc h - v eh i c le d y n a m i c p r e s s u r e , a n dwi th t he r e su l t i ng low d rag that facilitated the us e of the SM propuls ion sy s tem . Th ep a r a m e t e r s that w e r e e s t a b l i sh e d as max imal fo r t he opera t i on of t he LES w ere an alti-tude of 320 000 feet, a Mach num ber of 8.0, a n d a d y n a m i c p r e s s u r e of 0 . 5 t o

1.0 lb/ft .GROUND-BASED TEST P R O G R A M

Th e LES qua l i f ica t i on - t es t p rog ram cons i s ted of env i ronm en ta l t e s t i ng and statictest f i r i n g of LE S p i t ch -con tro l , t ower - j e t t i son , and l aunch -esca pe m o to r s . The s t a t i c

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test f i r i ng s cons i s t ed of f i r ing the LES s o l i d -p ro p e l l an t test m o t o r s a f t e r t h e p ro p e l -lants had been s tabi l ized at s e le c t e d t e m p e r a t u r e s . A l l static test f i r in g s w e r e a c c o m -p l i s h ed wi t h m o t o r s t h a t h ad p re f i r e s o l i d -p ro p e l l an t t em p e ra t u r e s of 20", 70", o r120" F. T h e s e t e m p e r a t u r e s r e p r e s e n t e d m i n im u m , n o m i n a l , a nd m a x im u m e x p e ct e dm o t o r t e m p e r a t u r e s . A l l LES s o l id - p r o p el la n t m o t o r s w e r e static test f i r e d at a n o m -i n a l p r e s s u r e of 14.7 p s i a .

Pitch Co n o l M o t o r Q u a li i c a t i on T es t P og r amE n v i ro n men t a l te s t i n g w as co n d uc t ed o n 14 p i t ch -co n t ro l m o t o r s . T h e p i tch -co n t ro l m o t o r s w e re d i vi d ed i n t o fi v e test g r o u p s : (1) emp era t u re cy c l i n g an d v i b ra t i o nt e s t i n g , (2 ) t e m p e r a t u r e c y c li n g an d d r o p t e s t i n g , (3) acce l e r a t ed ag i n g , (4 ) a c c e l e r a -t ion t es t ing , and (5 ) t e m p e r a t u r e - c y c l e t e s t i n g . Static test f i r i n g s w e r e co n d uc t ed o n1 7 p i t ch -co n tro l m o t o r s , i n c lu d i n g 10 m o t o r s th a t w e r e u s e d p r ev i o u s ly i n th e e n v i r o n -me n t a l t e s t in g . T h e p i t ch -co n t ro l m o t o r s we re d iv i ded in t o t h r ee g ro u p s b as ed o n p re -fire so l id -p rope l l an t t e m pe ra tu re s of 20" F (six m o t o r s ) , 70" F ( fo u r mo t o r s ) , an d

120" F ( s e v e n m o t o r s ) .Dur ing the qua l i f ica t ion phase of t es t ing , th e p i t ch -con t ro l mo tor m et all e n v i r o n -me n t a l an d s t ru c t u ra l - i n t eg r i t y test r e q u i r e m e n t s . A l s o , t h e m o t o r m e t allp e r f o rm a n c e - s p e c if i c a ti o n r e q u i r e m e n t s e x c e p t t h o s e f o r t h r u s t - r i s e t i m e . S p ec if i-c a ti o n r e q u ir e m e n t s f o r th r u s t - r i s e t i m e w e r e a minimum of 0.060 second and a m a x i -m u m of 0.110 second . One m otor tha t had a t h r u s t - r i s e t i m e of 0.117 s e c on d w a ss t a t i c t e s t f i r e d t o s i m u l a t e a f a i l u r e mo d e ( s i mu l a t i n g a n o z z l e - c l o s u r e f a i l u r e ) . T h i st h r u s t - r i s e t i m e w a s w i th in t h e s p e ci fi c at io n r e q u i r e m e n t s f o r t h e l a u nc h - e s c a pe m o t o r(a minimum of 0 .050 second and a maximum of 0.120 s eco n d ) , t h u s t h e d ev i a ti o n wa saccep t abl e b ecau s e t h e p i t ch -co n t ro l mo t o r w as i g n i ted co n c u r r en t l y wi t h th e l au n ch -e s ca p e mo t o r . T h e p it ch -co n t ro l mo t o r s p ec i f i ca t i o n w as ch an g ed t o ag ree wi t h t h et h r u s t - r i s e t i m e of th e l au n ch -e s cap e m o t o r .

Tower-Jet t i son M o t o r Q u a l i i c a ti o n -T e s t P r o g r a mT h e s t a t i c - t e s t - f i r i n g p h as e of t h e q u a l i f ic a t i o n - t e s t p ro g ram w as con d u c ted o n2 1 t o wer - j e t t i s o n mo t o r s , i n c l u d i n g 15 m o t o r s t h a t w e r e t e st e d e n v i ro n m e n t a l ly . T h em o t o r s w e r e d i v id e d i n to f o u r test g r o u p s : (1) e m p e r a t u r e c y c l i n g , (2) a c c e l e r a t e dag ing , (3 ) t em p er a t u r e cy c l i n g an d i mp ac t t e s t i n g , an d (4 ) v i b ra t io n t e s t in g , t e m p e r a -t u r e cyc l in g , and i mp ac t t e s t i n g . T h e t o w er - j e t t i s o n m o t o r s w e re d iv i ded i n t o t h r eeg r o u p s b a s e d o n p r e f i r e s o l id - p r o p e ll a n t t e m p e r a t u r e s of 20" F (n ine m otor s ) , 70" F( f ive mo tors ) , and 120 " F ( s ev en mo t o r s ) .It was n o te d i n t o w e r - j e t t is o n - m o t o r s p e c i f i c a t io n s t h a t c e r t a i n p e r f o r m a n c ep a r a m e t e r s m u s t be wi t h i n s p ec i f i c t o l e r an ces at t h e p r e f i r e p r o p e l l a n t t e m p e r a t u r e sof 20",70", nd 120" F; h o w e v e r , b e c a u s e of co n d i ti o n in g p ro b l e ms , t h e static-test-f i r i n g d a t a were obtained at s o m e w h a t d i f f e r e n t p r e f i r e p r o p e ll a n t t e m p e r a t u r e s .

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L a u n c h -Es c a p e M o to r Q u a l i i c a t i o n - T e s t P r o g r a mT h e q u a l i f i c a ti o n - te s t p r o g r a m c o n s i s te d of s t a t i c f i r i n g t e s t s of 20 l aunch -escapem o t o r s . F o u r t y p e s of t e s t s w e r e i nv o lv e d; t h e s e tests i nc lu d e d f i r in g ( s e v e n m o t o r s ) ,a c c e l e r a t e d a g i ng (tw o m o t o r s ) , t e m p e r a t u r e c y cl in g (f o u r m o t o r s ) , a nd s e q u e n t i a l

tests ( s even mo to r s ) . The s equen t i a l t e s t s cons i s ted of f i r i ng s even l aunch -esc apem o t o r s that w e r e s u b je c te d t o a speci f ic sequence of env i ronm ents . Six m o t o r s w e r eeach sub j ec t ed succes s ive ly t o a t e m p e r a t u r e - c y c l e t e s t , a d r o p t e s t , and a f i r i n g t e s t .One moto r w as sub j ec t ed suc ces s iv e ly t o a vibrat ion test, a t e m p e r a t u r e - c y c l e test,and a f i r i n g t e s t .A l l l aunch -esca pe-m oto r spec i f i ca t i ons t ha t concern ed ba l l i s t ic pe r f o rm ance ,env i ronm en ta l t e s t i ng , and thrust a l in e m e n t ( e x ce p t f o r r o l l- m o m e n t t e s t i n g ) w e r e m e t .T h e t e s t d a t a in d i ca t e d t h a t t h e m a x i m u m r o l l l i m i t of 130 foot -pounds w as exceeded fo rf i ve m o t o r s ; however , an op t i ca l check of t he nozz l es i nd ica t ed that the m a x im u m m i s -a l i nemen t would r e su l t i n a m a x im u m r o l l of n o m o r e t h an 4 foot-pounds. Th e highr o l l m o m e n t s w e r e a t t ri b u te d t o test stand lo ad c e ll m e a s u r e m e n t e r r o r s rather t han

t o a des ign de f i c iency .P i t c h - C o n t r o l M o t o r Q u a l i f i c a t i o n a nd P r o d u c t i o n P r o b le m s

The m a x i m u m c o m b u st io n - c h am b e r p r e s s u r e a n d the m a x i m u m t h r u s t of a qual i -f i ca t i on s t a t i c - t e s t - f i r ed p i t ch -con t ro l mo to r were abnorm al ly high fo r t he 20" Fprefire -condi t ion ing te m pe ra tu re of the mo tor . Al though the test results ind icated thatthe p i t ch -con t ro l mo to r had met all spec i f i ca t i on r equ i remen t s , an i nves t i ga t i on wasc o nd u c te d t o d e t e r m i n e the ca use of the anoma ly .P o s t f i r e i n spec t i on of the expended ha rdware r evea l ed that t h e r e w e r e tw o hots p o t s i n t h e c o m b u s ti o n c h a m b e r at t h e f o r w a r d girth weld . F u r th e r i n spec t ion of thec o m b u s t i o n - c h a m b e r i n t e r i o r r e s u l t e d i n e v id e n ce of p r e m a t u r e s o l id - p r o p e l la n t b u r n -o u t i n t h e s e areas. A rev i ew of t he p roc es s ing and t e s t r e c o r d s i nd ic a te d t h a t , a f t e rrad iog raph i c i n spec t i on of t he mo to r , a n o n co n fo r m a nc e r e p o r t w a s w r i t t e n t o d o c u m e n ttwo so l i d -p rope l l an t c r ac ks . One c r ac k w as l ocat ed midway be tween the g i r t h we ld onthe aft end o f t he combus t i on cham ber , and t he o the r c r ac k w as l oca ted at the f o r w a r dg i r t h w e ld a p p r o x i m a t e l y tw o w e b s f r o m t h e a r e a w h e r e t h e ho t s p o t s w e r e no te d . T h eM a t e r i a l R e v ie w B o a r d d e c i s i o n , b a s e d o n e x p e r ie n c e w i th d e f e c t s s u c h as t h e s e d u r i n gt h e d e v e lo p m e n t p r o g r a m , w a s t o a c c e p t t h e p i tc h - c o nt ro l m o t o r w i th o ut r e p a i r . I n theop in ion of t he M ate r i a l R ev iew B oard , t hese de fec t s ( so l id -p rope l lan t c ra ck s ) would no ta f fe c t b a l l i s t ic p e r f o r m a n c e m a t e r i a l l y , w h e r e a s r e p a i r w ou ld n e c e s s i t a t e e x t e n s i v e

so l i d -p rope l l an t r emov a l . B ased on t he results of the inves t igat ion , the d e f e c t s at theg i r t h weld p ropag a t ed a long the we ld ; thus , a l a rge a r e a of so l i d -p rope l l an t unbond w a sproduced du r ing s t a t i c test f i ri n g . T h e c o r r e c t i v e a c t io n t o p r e v e n t a r e c u r r e n c e oft h i s a n o m aly w a s t o r e p a i r all s o l id - p r o p e l la n t c r a c k s b e f o re s h ip m e n t .D u r i ng t h e d r o p test of a pi tch-cont ro l motor that w a s b e i ng s u b j ec t e d t o t e m p e r a -t u r e c y c l i n g an d d r o p te s t i n g b e f o r e s t a t i c f i r in g , a n o t h e r f a i l u r e o c c u r r e d . The d r o ptest w a s p la n n ed t o d e m o n s t r a t e that the motor could be handled safe ly . The p i tch-c o n t r o l - m o t o r s o l id p r o p e l la n t w a s t e m p e r a t u r e c yc le d by m e a n s of s u c c e s s i v e stabili-za t i on at - 20" , 140", 20" , 140", and -20" F. At the f i na l -20" F condi t ion, thep i t ch -con t ro l m o to r w as pos i ti oned wi th the longi tudinal axis v e r t i c a l a nd the nozz l e

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t w o - l a y e r v i n yl -t a p e c o v e r o n t h e b o ro n / po t a ss iu m n i t r a t e p e l l e t c o n t a i n e r w a s r e d u c e dt o a s i n g l e - l a y e r - t a p e c o v e r t o p e r m i t easier t ape bu rn th rough . Th i s i gn i t e r i gn i ti on -d e l a y m a l f u n ct io n o c c u r r e d d u r i n g t h e t i m e t ha t t h e t o w e r - je t t is o n m o t o r w a s d u p l i c a -t i ng a doub le - fa i l u re mode (a f a i l ed i n i t i a t o r and a f a i le d n o z zl e c l o s u r e ) , a nd t h e r e isn o r e q u i r e m e n t f o r s u c c e s s f u l d e m o n s t r a t i o n w ith th e t o w e r - je t t is o n m o t o r u n d e r t h e s econd i t ions . B ec ause the i gn i t e r a s sem bly w as mod if ied and because a doub le - fa i l u rem o d e w a s b ei n g d u p li c a te d , t h e test r e s u l t s of t h e f a i le d m o t o r w e r e d e l e t e d f r o m t h ep e r f o r m a n c e e v a l u a t i o n . F

After t he com ple t ion of t he t ow er - j e t ti son m o to r qua l i f i ca ti on - tes t p r og ra m , ani g n i t e r - t e s t p r o g r a m w a s c o n du c te d t o v e r i f y th a t t h e i g n i t e r m o d i f ic a ti o n s w e r e s u c -c e s s f u l . T h i s p r o g r a m w a s c o m p l e te d w i th ou t a n y f a i l u r e s .F a i l u re of t he i n t e r s t a ge s t ru c tu re of t he t h i rd t ower - j e t t i son mo to r t ha t w ass t a t i c test f i r e d c a u s e d t h e s u b se q u e n t d e s t r u c ti o n of t h e m o t o r a s s e m b l y . T h e f a i l u r e ,wh ich o r ig ina t ed at t h e i n t e r s t a g e s t r u c t u r e f o r w a r d a nd aft a t ta c h m e n t r i n g s , w a scau sed by she a r f a i l u r e of t he spo twe lds t ha t were u s ed t o a t t a c h t h e r i n g s t o t h e i n t e r -s t a g e s t r u c t u r e . B e c a u s e t h e r i n g s b e c a m e d e t ac h e d , t h e s o l id - p r o p e l la n t m o t o r p u ll edfree f r o m t h e test s tand , impac ted on the head-end wa l l of the test b a y , a n d s h a t t e r e dt h e m o t o r a s s e m b l y . D u r i n g p o s t f i r e i n sp e c ti o n , it w a s n o te d th a t t h e i n t e r s t a g e afta t ta c h m e n t r i n g w a s still b o lt ed t o t h e t e s t s ta n d , a nd t h e f o r w a r d a t t a c h m e n t r i n g h a drem ain ed bo lt ed t o t he m o to r a f t c l o su r e . By examina t i on of t he she a re d spo tw e lds onbo th r i ng s , ev idence of i nadequa t e we ld ing wa s ob t a ined . Dur ing subsequen t i nves t i ga -t ion of the spotweld ing ope rat ion , it w a s a s c e r t a i n e d t h a t i m p r o p e r m a t i n g of t h e c o m -p o n e n t s t o be welded cou ld have been an im por t an t f ac to r t ha t had con t r i bu t ed t o t heinadequa t e we lds . It w a s d i s c o v e r e d a l s o t h a t on e w e l d e r h a d r e w e ld e d t h o s e w e l d st h a t d id n o t p a s s v i s u a l in s p e c t io n . T h i s w ou ld h av e r e s u l t e d i n w e ld e m b r i t t l e m e n tand fa i l u re at l o w e r stress. Th ese f a c to r s l ed t o t he conc lus ion t ha t t he i n t eg r i t y oft he spo twe lds on all of t h e r e m a i n i n g i n t e r s t a g e s t r u c t u r e s w a s q u e s ti o n ab l e; t h e r e f o r e ,

t o p r e v e n t f u t u r e f a i l u r e s , t h e s p o t w e l d s of all of th e r e m a i n i n g i n t e r s t a g e s t r u c t u r e sw e r e s u p p le m e n t e d w i t h h i g h - s h e a r r i v e t s . Also, a p r o c e d u r e w a s i n c o r p o r a te d t oproof- load test all i n te r s t a g e s t r u c t u r e s at 1 . 1 5 t i m e s t h e d e s i g n l o a d , a n d a n o t h e rso l i d -p rope l l an t t ow er - j e t t i son mo to r w as added t o t he qua li f ica t i on -t es t p r og ra m tor e p l a c e t h e f a i l e d m o t o r .To v e r i f y t h e s t r u c t u r a l i n t e g r i t y of t h e r e d e si g n e d i n t e r s t a g e a s s e m b l y , tw oi n t e r s t a g e s w e r e s u b je c t ed t o t h r e e c y c l e s of p ro of l oa d in g ; t h en , t h e tw o i n t e r s t a g e sw e r e l o ad e d u n t il f a i l u r e o c c u r r e d . Failure was c o n s i d e r e d t o b e t h e p o i nt at whichin t e r s t a ge - s t ru c tu re de fo rm at ion con t inued wi thout a c o r r e s p o n d i n g l oa d i n c r e a s e . T h et w o i n t e r s t a g e s f a i l ed at pu l l l oads of 2.5 and 2.6 t i m e s th e d e si g n l o a d s , r e s p e c t i v e l y .T h e s e p u l l l o a d s w e r e g r e a t e r t ha n t h e u lt im a t e -l o a d r e q u i r e m e n t of 1 . 5 t i m e s t h e d e -s ign l oad . No r i v e t o r spo twe ld connec t i ons f a il ed du r ing t he u l t ima te - l oad tests. A sa r e su l t of the suc ces s fu l p roo f- load and u l tima te- load t e s t i ng , t he s t ru c tu ra l adequacyo f t h e i n t e r s t a g e r e d e s i g n w a s p ro v e n .

L a u n ch E s ca pe Mo to r Q u a l i ica t ion and P r o duc t io n Prob1em sL a u n c h - e s c a p e m o t o r cases w e r e m a n u f a ct u re d i n f o u r l o t s . D u r i n g t h e lo t 2a c c e p t a n c e test, o n e l a u n c h - e s c a p e m o t o r c a s e f a il e d at 2300 p s i g d u r i n g th e s e v e n t hp roo f cyc l e (2400 f 50 p s ig ) . T h i s f a i l u r e w as a t t r i bu t ed t o a weld defect . T h i s m o t o r

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ca s e w as b e in g u s ed t o v e r i fy t h e ad eq u acy of all t h e c a s e s f a b r i c a t e d i n lo t 2. It hadbeen subjected to six proof cyc les and the seven th test w a s t o h av e p r o c ee d e d t o burstp r e s s u r e w hen th e f a i lu r e o c c u r r e d . The fa i lu re inves t iga t ion conc luded tha t , i f th ecase had been sub jec ted to X-ray inspec t ion befo re the f ina l t es t , t he weld f l aw wouldh ave b een d e t ec ted . Ad d i ti o na l ly , t h e max i mu m o p e r a t i n g p r e s s u re w as 1800 p s i a ;t h e r e fo re , t h e ca s e h ad s h o wn a s a f e t y f ac t o r of 1.3. Bas ed o n t h i s r a t i o n a l e and be-c a u s e all ca s e s w e re s u b j ect ed t o X - ray i n s p ec ti o n a f t e r p ro of t e s t i n g , it w a s c o n-c l ud ed t h a t n o co r r ec t i v e ac t io n was r eq u i r ed .Dur ing the lo t 3 accep tance test, a l a un c h -e s ca p e m o t o r c a s e t h a t w a s b e in gtes ted fa i l ed at 2270 p s i g d u r i n g th e t h i rd p ro o f c y c l e (2400* 50 ps ig ) . Bec ause of th i sfailure, a s eco n d mo t o r ca s e w as a s s i g n ed t o th e l o t 3 a c c e p t an c e t e s t p r o g r a m , an dt h i s m o t o r c a s e f a il e d at 2250 ps ig dur ing the th i rd p roof cyc le (2400 * 50 ps ig ) . Bym ea ns of meta l lu rg ica l exam ina t ion , it w as shown tha t an unquali fi ed weld w i r e w asused in the manufacture of the lo t 3 l a u n c h -e s c a p e m o t o r c a s e s ; t h e r e f o r e , all lo t 3m o t o r c a s e s w e r e r e j e c t e d , a nd q u a li ty c o n t r o l p ro c e d u r e s w e r e i m p o se d o n t h e s u p -p l i e r t o e n s u r e t h a t t h i s failure would not occur again .Dur ing p roduct ion-accep tance s t a t i c f i r ing of a l au n ch -e s cap e mo t o r , t h e i n n e rf i b e r -g l a s s s o l i d -p ro p e l lan t g r a i n s u p p o r t of t h e p y ro g en i g n i t e r b ro k e l o o s e f ro m itsre ten t ion dev ice and ex i ted th rough the nozz le , s t r ik in g and b reak ing o ff the nozz le ex i tcone approx imate ly 6 i n c h e s f r o m t h e e n d. T h e r e s u l t s of an inves t iga t ion ind ica tedtha t the p re ss ur e of the m otor ign i t ion caused the pheno li c p lug in the end of the inn erf i b e r -g l a s s s o l i d -p ro p e l lan t g r a i n s u p p o r t t o b e fo r ced fo rward , i mp ac t in g t h e en d ofthe sup por t and expand ing ; th i s cou ld have b roken the bond be tween the pyroge n a ss em -b ly and the inne r f ib er - g la ss so l id -p rope l l an t g ra in suppor t (f ig . 4 (b ) ) .A d e ci si o n w a s m a d e to r e d e s i g n t h e i g n i t e r t o i m p r o v e t h e i n n e r f i b e r - g l a s ss o l id -p ro p e ll an t g r a i n - s u p p o r t c ap ab i l i t ie s b y mak i n g t h r e e ch an g es. A t ens ion rodw a s a d de d in th e i n n e r f i b e r - g l a s s s o l id - p r o p e ll a n t g r a i n s u p p o r t t o r e t a i n t h e s u p p o r t

i f a f a i l u r e o cc u r r e d . L a t e r a l d i s p l acemen t of t h e i n n e r f i b e r -g l a s s s o l i d -p ro p e l l an tg ra i n s u p p o r t at the a f t end dur ing f i r ing of the l aunch-escape m oto r w as p reven ted .T h e t o t a l m a s s of p a r t s w a s m i n im i z e d t o be co n s i s t en t wit h t h e o t h e r t wo ch an g es .To v e r i fy t h e s t ru c t u ra l i n t eg r i t y of t h e i mp ro v ed i g n i t e r u n d e r o p e ra t i n g co n d i -t ion s , the fo llowing t e s t cond i t ions were used .1. O v e r t e s t s at e x t r e m e t e m p e r a t u r e c o nd it io n s2. O v e r t e s t s at h ig h i g n i t e r -p r e s s u r e co n d i ti o n s3 . N o r m a l t e s t s of i g n i t e r s p r e v i o u sl y e x p o s ed t o t e m p e r a t u r e c y c li n g o r t ov ib ra t ion cond i t ions4. No rma l t e s t s of i g n i t e r s d u r i n g v i b ra t i o n co n d i t io n s5. N o r m al t e s t s of i g n i t e r s i n f u l l - sc a l e l a u n c h -e s c a p e m o t o r s6 . S t r u c t u r a l t e s t s t o f a i l u r e ( h y d r o b u r s t tests) of ign i t e r iner t componen t s

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T e s t - p r o g r a m r e s u l t s in d i ca t ed t h a t th e i m p r ov e d - de s ig n i g n i t e r p e r fo r m e ds a t i s f a c t o r i ly u n d e r e x t r e m e - t e m p e r a t u r e c o nd it io n s, h ig h i g n i t e r p r e s s u r e s , a ndwi th in t he spec i f i ca t i on r equ i remen t s . A minimum des ign m ar gin of safe ty of 1 . 4 w a sd e m o n s t r a t e d i n t w o s t r u c t u r a l t e s t s . The improved i gn i t e r des ign sus t a ined minorer os ion of the ou ter so l id-prop el lan t gr a in suppor t up s t r ea m of the junct ion wi th theign i ter noz zle . How ever , the ex ten t of eros ion w a s s o s l igh t that the in teg r i ty of thei g n i t e r w a s no t c o m p r o m i s e d .

PAD-ABORT TEST PROGRAMT h e p a d - a b o r t t e s t p r o g r a m w a s d e si gn e d t o pr o v id e a m ea ns by wh ich the LESpad-abo r t c apa b i l i t i e s could be dem ons t ra t ed . The t e s t p ro g ra m invo lved two f l i gh t s .

On both f l igh ts , the U S e q u i r em e n t s w e r e to pro pe l an unmanned Apol lo- type bo i ler -p l a te s p a c e c r a f t f r o m a l aunch pad to suff ic ien t height and or ien ted to the proper atti-tude so t ha t t he spa cec ra f t e a r t h land ing sys t em cou ld func t ion p rope r ly .

Apollo Pad Abort 1M i s s i o nThe Apol lo pad abor t 1 ( P A - 1 ) m i s s i o n was t h e first f l igh t test of a n Ap ollo-ty pes p a c e c r a f t . A l l f i r s t - o r d e r test ob jec t i ves of t he Apo llo P A-1 mi s s ion we re s a t i s f i e d .Aerodynamic - s t ab i l i ty ch a r ac t e r i s t i c s of t he Apol lo escap e con f igu ra ti on du r ing a pada b o r t w e r e d e t e r m i n e d . T h e LES and CM conf igurat ions were s t ab l e du r ing t he f l i gh t ;how ever , p i t ch , yaw, and ro l l w er e no t as predic ted dur in g the powered ph ase of thefl ig ht . The cap abi l i ty of the LES o p r o p e l a CM to a s a f e d i s ta n c e f r o m t h e l a u nc hvehic le w a s d e m o n s t r a t e d .The m os t s igni f icant anom aly of the Apollo PA -1 m iss ion app eare d dur in g thepos t f l igh t inves t igat ion . It w a s d i sc o v e r e d that l aunch -escape -mo to r exhaus t pa r t i c l e shad imping ed on the CM and had caus ed soot dep os i t s . A s a r e su l t of t h i s anomaly , aboos t p ro t e c t i ve c ove r fo r t he C M w as p rov ided on subsequen t veh i c l es .

Apollo P ad Abort 2 M i s s i o nThe Apo l lo pad abo r t 2 (P A-2 ) mi s s ion , t he s econd pad -abor t test, w a s r e q u i re dbecause of space c ra f t - con f igu ra t i on ch anges t ha t had been made . Th ese changes i n -c lu d e d c h a n g e s in m a s s c h a r a c t e r i s t i c s , t h e a dd it io n of a canard subsy s t em , and t headdi t ion of the CM boos t pro tect ive co ve r . A ll ob je cti ve s of the test were a c c o m p l i s h e dsucc es s fu l l y . The fl i gh t s equence of m a jo r even t s fo r the Apo llo P A-2 m i s s ion is givenin f i gu re 5 .A s p l anned , t he l aunch -escape mo to r and t he p i t ch -con t ro l mo to r w er e i gn i teds imu l t aneous ly . A mod era t e pos i t i ve - ro l l r a t e deve loped at l if t -o f f ; t h i s w as a t t r i bu t edt o t h e a e r o d y n a m i c a s y m m e t r y of t h e ve h ic l e c o n f ig u r a ti o n. T h e r o l l rate d id no t com -p r o m i s e t h e s u c c e s s of t h e m i s si o n . T h e c a n a rd s u r f a c e s w e r e d ep lo y e d s a t is f a c t o r i l yto des t a b i l i ze t he con f igu ra t ion and t o t u rn the con f igu ra ti on t o a main -hea t - sh i e ld -fo rward cond i t i on at t he t ime of t he d rogue-parachu te dep loymen t . Dur ing t he t u rn -a r o u n d m a n e u v e r , t h e LES and t he apex cover we re j e t t isoned succes s fu l l y .

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G r o u n d r a n g e I tT ime f rom l i l t - o l l ,

Event sec1. LI I I -of12. Canard dep loyment3 . l owe r j e t t i son4. CM apex-cover jet t is on5 . Drogue-parachute dep loyment6. Dr ogue - pa r ac hu t e d i s c onnec t7. Pi lo t -parachute dep loyment8. M a i n pa r ac hu tes lul l open9. CM land ing

010.914.014.416.028.628.645.5

112.6

F i g u r e 5. - M ajo r even ts of Apol loP A-2 mi s s ion .

LITT LE JOE TEST PROGRAMThe L i t t l e Joe f l igh t test p r o g r a mcon s is te d of f ive launch es of s im ula ted CMon L i t t l e Joe I1 l aunch veh i c l es . The L i t t l eJ o e I1 test p r o g r a m w a s c on d u ct ed at th e

Whi t e S ands M is s i l e R ange , New Mex ico .The p r im ar y ob j ec t i ves of t he L i t t leJ o e I1 f l ig h t s w e r e t o d e m o n s t r a t e t h a t t h eL E S co u ld s a fe l y a b o r t t h e C M u n d e r c r i t i -cal f l i gh t cond i t ions , t o ve r i fy t he i n t eg r i t yand re l ia b i l i ty of the ea r t h landing sy s te ma f t e r a n a b o r t , a nd to c o n f ir m t h e s t r u c t u r a li n t eg r i t y of t he ea r t h l and ing sy s t em and t heC M when exposed t o critical a b o r tcond i t i ons.T h e first flight of a qua l i f i ca t i on - t es tveh ic le wa s launched on Augus t 28 , 1963.A series of four Li t t l e Jo e II l a un c h e s w a sconducted on bo i lerp la te s of pro to type Apol lospa ce cra f t . The ob j ec t i ves of t he L i t tl eJ o e I1 test p r o g r a m are s u m m a r i z e d i ntable 11, a nd t h e m a j o r e v e n t s are shown inf i g u r e s 6 t o 9 .

Each of t he ab o r t m i s s io ns r esu l t ed i n so f t l and ings of t he C M bo i l e rp l a t es ; t h i si nc luded one unschedu led i n f l igh t emerg ency ab o r t t ha t w as caus ed by a malfunc t ion ofthe l aunch veh i c l e con t ro l sy s t em . S hor t ly a f t e r l i ft -o f f on t he Apo llo A-003 m i s s io n ,t he L i t t l e Joe 11 l aunch veh ic l e began an uncon t ro l led ro l l t ha t acce l e ra t ed as t he f l i gh tve loc i ty i nc rea sed . B efo re s econd-s t age i gn i ti on and wh i le still at low al t i tude , theL i t tl e J o e I1 l aunch veh i c l e d i s i n t eg ra t ed . An unp lanned (bu t succ es s fu l ) l ow-a l ti t udea b o r t w a s s ta r t e d 2 6 . 3 s e c on d s later, a n d s a t i s f a c t o r y e a r t h l a n di ng o c c u r r e d a p p r o x i -m a t e l y 4 . 5 m i n u t es later. B ecau se of t he ea r l y b rea kup of t he L i t t l e Jo e 11 l aunch veh i -cle, the high-a l t i tude-te st point (120 000 feet) w a s n o t a c h i e v ed , but a s u c c e s s f u llow-al t i tude (12 4 00 f e e t ) a b o r t f r o m a r ap id ly ro l l i ng ( app rox imate ly 335" / s ec ) l aunchv e h i c le w a s d e m o n s t r a t e d . A t t h e t i m e of t h e a b o r t , t h e M a c h n u m b e r , t h e d y n a m i cp r e s s u r e , a nd th e a l ti tu d e w e r e c l o s e t o S a t u rn IB and S a tu rn V nomina l - l aunch -t r a j ec to ry cond i t i ons .

The L i t t le J oe I1 test series res u l te d in the qual i f ica t ion of the Apol lo LE S and theC M e a r t h la n din g s y s t e m f o r m a nn ed m i s s i o n s . If t h e tests had been manned mi s s ions ,the crew me n would have landed sa fe ly .

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T A B L E 11. - L I T T L E J O E I1 FLIGHT PROG RAM-OBJECTIVES

Developmenti s s u e sP e r f o r m a n c e

In t eg r i t y

P r o c e d u r e s

I Env i ronmen t

(a) LE S launch -vehic le q ual i f ica t ion

~

Ob e c i v e sDem ons t ra t e capab i li ty t o pe r fo r m the l au n ch t r a j e c t o r y f o r

Dem ons t ra t e a b i l i ty o f launch veh ic l e t o c l ea r the l auncheraDem ons t ra t e Algo l t h rus t - t e rmina t ion sys t em aDem ons t ra t e func t iona l and s t ruc tu ra l adequacy of g round-suppor t

~ p o 1 1 0A-001 miss iona

bequ ipmen tD e m o n s t r a t e that f i n s are f l u t t e r f r eeaDem ons t ra t e s t ru c tu ra l i n t eg ri t y fo r Apo llo A-001 mi s s iona

~

De mo nst ra te adequacy of the pro ced ure f or wind compensat ion byaa iming l aun cher i n az imu th and e l eva ti onEva lua t e t echn iques and p roce dures wh ich con t r i bu t e t o e f f i c ien t

bl aunch opera t i on sEva lua t e p roc edure s f o r ground-command abo r t fo r app l i ca ti on t obApollo A-001 mission

~~~ ~~

D e t er m i ne b a s e p r e s s u r e sD e t e r m i n e base hea t i ngDe termin e f lex ib le body resp ons e of to ta l l aunc h veh ic le p lus payloac

F i r s t - o r d e r test object ive .bS econd-o rder t e s t ob j ec ti ve .

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TABLE 11. - L I T T L E J O E I1 F LIGHT P R OGR AM OB JEC TIVES - Continued(b ) Apo llo A-001 m i s s ion t r anso n i c a bo r t at h ig h d y na m i c p r e s s u r e

~~

Abo rt capabi l ity De mo ns t ra te the capabi l i ty of the LES to p rop e l t he C M sa fe lyaaway f rom the l aunch veh i c l eS tabi l i ty D e t e r m i n e a e r o d y n a m i c s t a b il i ty c h a r a c t e r i s t i c s of th e e s c a p eaconf igu ra ti on fo r t h i s ab o r t cond it ion

aS t ruc tu ra l i n t eg r i t ya n d p e r f o r m a n c e D e m o n s t r a te t h e s t r u c t u r a l i n te g r i ty of t h e e s c a p e to w e r

Separat ion D e m o n s t r a te s a t i s f a c t o r y t i m i n g s e q u e n c e i n th e e a r t h la n d in gas y s t e m=

I L E S i s s u e s 1 O b j e c t i v e s

R ecovery wi th ea r t hl and ing sy s t em Dem ons t ra t e p r op er ope ra t i on of t he app l i cab l e componen t s ofat h e e a r t h l an d in g s y s t e m

Effe ct s induced byenv i ronmen t

D e m o n s t r a te p r o p e r o p e r a t i o n of t h e CM/SM s e p a r a t i o nbs u b s y s t e mD e t e r m i n e a e r o d y n a m i c l o a d s t h a t a r e c a u s e d by l o c a l s u r f a c e

p r e s s u r e on t h e CM a nd SM dur ing a L i t tl e J o e I1 l aunchb

~

L ES i s s u e sAbor t capabi l i ty

(c) Apollo A-002 m i s s io n ab o r t at m a x i m u m d y n a m i c p r e s s u r e

Ob ec i v e sD e m o n s t r a te s a t i s f a c t o r y l a u n ch e s c a p e v e h i c l e ( L E V ) p e r f o r m -ance by t he u se of t he ca nard subs ys t em and boos t p ro t e c t i ve

c o v e r , a nd v e r i f y t h e a b o r t c a p a b il i ty at m a x i m u m d y n a m i cp re s s u re with cond i t ions t ha t app rox imate t he l im i t s of t hee m e r g e n c y d e te c ti o n s y s t e m a

D e t e rm i n e t h e p e r f o r m a n c e of the L E V in th e m a x i m u m -bd y n am i c - p r e s s u r e r e g io n

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TAB LE II. - L I T T L E J O E 11 FLIGHT PROGRAM OB JECTIVE S - Cont inued(c) Apollo A-002 m i s s i o n a b o r t at m a x i m u m d y n a m i c p r e s s u r e - Concluded

L E S i s s u e sS tabi l i ty

S t r u c t u r a l i n t e g r i tya n d p e r f o r m a n c e

~

S epara t i on

S epara t i on

R e c o v e r y w i th e a r t hl and ing sys t emEffec t s i nduced bye n v i r o n m e n t

Ob jec t i vesD e m o n s t r a te s a t i s f a c t o r y po w e r- o n s t a b il i ty f o r a b o r t in them a x i m u m - d y n am i c - p r e s s u r e r e g i o n with condi t ions that

a p p r o x i m a t e e m e r g e n c y d e te c t io n s u b s y s t e m l i m i t sD e m o n s t r a te s a t i s fa c t o r y c a n a r d d e p l o ym e n t , t u r n a r o u n d d y n amics , and main -he a t - sh i e ld - fo rward f l igh t s t ab i l i ty be fo re LES

jet t i son

b

bD e m o n s t ra t e t he s t r u c t u r a l p e r fo r m a n c e with the c a n a r d

Cs u b s y s t e mD e m o n s t r a te th e s t r u c t u r a l p e r f o r m a n c e of the b o o s t p r o t e c t i v ec o v e r d u r i n g a n a b o r t in the m a x i m u m - d y n a m i c - p r e s s u r e

r e g i o nCD e m o n s t r a te s a t i s f a c to r y s e p a r a t i o n of the L E S a n d b o o s t p r o -bt ec t i ve cover f rom the C MD e m o n s t r a te s a t i s fa c t o r y v e h i cl e s e p a r a t i o n f r o m the SM at a

se le cte d ang le of a t tack'D e m o n s t r a te s a t i s f a c t o r y o p e r a t i o n a n d p e r f o r m a n c e of the eartlbl anding sys te m by the us e of reefed dual d r o g u e s

~~~~ ~-Dete rm ine the CM pr es su re l oads , i nc lud ing pos s ib l e p lumebimp ingemen t , i n the m a x im u m - d yn a m ic - p r e s s u r e r e g i o n

the l aunch phase 'D e t e r m i n e t h e a e r o d y n a m i c p r e s s u r e l o a d s o n t h e SM d u r i n g t he

O b t ai n t h e r m a l e f f e c t s data o n th e CM d u r i n g a n a b o r t i n th em a x i m u m - d y n am i c - p r e s s u r e r e g i o n L

bSecond -or der test object ive .' T h i r d - o r d e r test object ive.

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TABLE 11. - L I T T L E J O E II FLIGHT PROGRAM OW EC TIVE S - Continued(d) Apollo A-003 m iss io n h igh-a l ti t ude a bo r t

L E S i s s u e sAbor t capabi l i ty

Stabi l i ty

S t ruc tu r a l in t egr i tyand pe r fo rm anceSeparat ion

R e c o v e r y w i th e a r t hl anding sys t em

Eff ec ts induced byenvi ronm ent

Dem ons t ra t e sa t i s f ac to ry pe r fo rm an ce of the LEV at a n a l ti t u d eof a p p r o x i m a t e l y th e u p p e r l i m i t f o r t h e c a n a r d s u b s y s t e m a

Dem on s t r at e o r i en ta t ion o f the L EV to a m ain-hea t - sh ie ld -fo rw ard a t t i tudea

Determine the damping of osc i l la t ions in the LEV with the can ardbs u b s ys em dep loyedDe te rm ine the phys ica l behav ior of t he boos t p ro tec t ive cove r

Cdur ing l aunch and dur ing en t ry f ro m h igh a l t i t ude~~~ ~ ~~

Dem on s t r at e j e tt i son o f the LES wi th the boos t p ro tec t iv e co ve rba f t e r h igh - a l ti t ude en t ryDem on s t r at e pe r fo rm an ce of the sy s t e m by the u se of the two-

Cp o in t h a r n e s s a t ta c h m e n t f o r t h e m a i n p a r a c h u t e s3 b t a in d a t a o n t h e r m a l e f f e c t s d u r i n g b o o s t a n d d u r in g i m p i ng e -m ent of t he l aunch-e scape m o tor p lum es on the CM and the

launch-escape tower

launch and high-a l t i tude abort'

CDete rm ine p r e s su re s on the CM boos t p ro tec t ive cove r du r ing

D e te rm i n e v i b r a t i o n a n d a c o u s t i c e n v i r o n m e n t a n d r e s p o n s e o fCt he SM reac t ion con t ro l sys t em wi th s im ula t ed quads

aF i r s t - o r d e r test objec t ive .bSecond-order t es t objec t ive .T h i r d - o r d e r t e s t o b j e c ti v e.

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TABLE II. - LITTLE JOE I1 FLIGHT PROGRAM OBJECTIVES - Concluded(e) Apollo A-004 mission abo rt in the power-on tumbling boundary region

LES issu es4bort capability

Stability

Structural integrityand performa nce

Separation

Recovery with earth

Effects induced byenvironment

Objectives~ ~~ ~~Demonstrate sa tisfactor y performance of the LEV for an abortain the power-on tumbling boundary region

Demonstrate the capability of the cana rd subsystem to sat isfac-torily re orie nt and stabilize the heat shie ld of the vehicle ina forward at t itude after a power -on tumbling ab or tb

Demonstrate the s truc tura l integrity of the a i r f r ame s t ruc tu reafor an abo r t in the power-on tumbling boundary regionDemonstrate the stru ctu ral capabili ty of the production spac e -bcr af t to withstand the launch environm entDem onstrate the capability of the CM forw ard-h eat-sh ieldt h r u s t e r s to sat isfactori ly sep ara te the forward heat shield

after the tower has been jettisoned by the tower-jettison motoiDemonstrate s atisfacto ry separation of the LEV from SMC

~ ~~ ~~Demonstrate satisfactory operation and perform anc e of the sy s-tem with a production spacecraft'

Determine the static loads on th e CM during launch and duringbthe abort sequence bDetermine the dynamic loading on the CM inner structureDetermine the dynamic loads and the s t ructura l response of thebSM during launch

st re am conditions and by LES motor plumes d uring a power-on tumbling abortof o pera tion of the earth landing system'

Determine the stat ic pre ssur es imposed on the CM by free-b

Obtain data on the structura l res pon se of the CM during sequenceObtain the rm al data on the boost protective cove r during a

Cpow er -on tum bling ab ortCObtain acoustical noise data inside the CM at an astronaut s tat ion

aF i r s t -o rde r test objective.bSecond-order test objective.

Third-order test objective.19


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Time lro m lift-offMa pr events sec1. Lift-off 02 . Thrust terminat ion and a k r t 28.53 . LES motor burno ut and coast - -4. Tower and forward-heat-sh leldseparatmn 44.05. Drogue-parachu te deployment 48.06. Pilot-parachute deployment 116.07. Mai n parachute full nllat ion 121.08. CM landing 350 .3

Figure 6 . - Major events of Apollo A-001mission.

0 b k 12 16 20 2 4 x 10w2v/ Range ItEvent rec

Time from l i l t 011

I L l l l O f l 01 Canard deployment 37 34 Tower jettison 0 0 45 Apex cover leltison 0 0 86 orogue parachute deployment 47 57 Pilot p ardchule deployment 84 Pt Main patdchuter fu ll open 106 09 CM landing w7 8

1 Abort initiation 26 3

Figure 8 . - Major events of Apollo A-003mission.

i1. Launch2. Pl tch-up3 . Abort4 . Coast5 . Deploy canards and6. Jettison tower1 . Deploy drogu e

parachute8. Deploy pilotparachutes9. In f la te main

parachutesIO. Landing 01 CM

lurn around

&

7 M8 Y

b

Figure 7 . - Major events of Apol lo A -002mission.

Range, ItTime lrom lilt-of1Event sec

1. Lilt-offI81700.776a.m. m.r.t.1 36.43 Mach 1.0 4 1 . 84 . Maxq 70 815 Pitch-up init iation 70.81

2 Staging 38.7

6 Abort initia tion 73.77. Canar d deployment 8 4 . 88 Tower jettison 193.89 . Drogue-parachute deployment 19 5 8IO. Main -para chute deployment 237.611 . Main-parachute disconnect 410 012. CM landinq 410 0

-Figure 9 . - Major events of Apollo A-004mission.20


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S A T U R N A N D APOLLO U N MA N N E DFLI GHT-TEST PROGRAMT h e S a t u r n f l ig h t - te s t p r o g r a m w a sconduct ed on t he bo i l e rp l a t e Apo llo spa ce -craft, produc t ion - type l aunch esc ap e sys -t e m s , a nd S a t u r n I l aunch veh i c l es ( fi g. 10).T h i s p r o g r a m w a s d e s ig n e d t o s ho w th ecompat ib i l i ty of the Apol lo spacecraf t sys -t em wi th t he S a tu rn - type l aunch veh i c l e .T h e S a t u r n f l i g h t - te s t p r o g r a m i nv o lv e d tw ounmanned mi s s ions .In the first test (AS-101) , de pic ted inf i g u r e 11, t h e n o r m a l to w e r - j e tt i so n m o dew a s s u c c e s s f u l l y d e m o n s t r a t e d . T h e

l aunch-escape and p i t ch -con t ro l mo to r sw e r e i n e r t. In t he s econd test (AS-102),depic ted in f igur e 12 , the backup mode oftowe r j e t t ison us ing t he l aunch -escape andp i tc h - c o n tr o l m o t o r s w a s s u c c e s s f u l lyd e m o n s t r a t e d . T h e r e w e r e f o u r u n m an n edApo l lo mi s s ions , all of which involved aqual i f icat ion configurat ion of the launche s c a p e s y s t e m , a n d all of these f l ightsused a n o r m a l t o w e r - j e t t i so n m o d e.

120 r

Event1. Saturn 5 -1 lift-off2. Saturn 5-1 engine shutdownInboard enginesOutboard engines3. Separation

20 5 . LE S tower jettison6. Saturn S - E shutdown

.-

& a._4

Time from lift-off,secPlanned Actual0 0

14l.1 142.8

146.5 149.2148.2 150.2158.5 161.2625.8 624.5

146.1 148.8

10 2 0 0 4 0 0 6 0 0 8 0 0 1 mI I 1 I I0 Range, n. mi.

F i g u r e 11. - M a j o r e v e n t s of ApolloAS-101 miss ion .

LE S (diameter - 26 in.)i n .

761

F i g u r e 10. - Apol lo BP -13.

in

2 Saturn 5-1 shutdownInboard enginesOutb ard engines4. Saturn S-Lp ignition6. Saturn S - U ! shutdown

0 2 0 0 4 a ) K m 8 aRange n. mi

a 0 0b 140.9 141.3146.9 147.4c 147.1 148.2d 149.4 149.9e 159.7 160.2619.3 621.1

F i g u r e 1 2 . - M ajor ev en ts of Apol loAS-102 mission.

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MANNED-FLIGHT PROGRAMThrough the luna r -l and ing m iss ion , f ive m anned m iss io ns invo lved qua l if i cat ionconf igura t ions . T h e r e w e r e n o a b o r t s t h a t re q u i r e d t h e u s e of t h e L E S. D u r in g e a c hof these m i s s i o n s , t h e t o w e r - je t ti s o n m o t o r s w e r e u s e d , a nd th e p e r f o r m a n c e w a s

n o m i n a l .RESULTS

A su m ma ry of Apol lo LES qual i f ica t ion f l ights is given in t ab le 111. T h e c a p a b i l-i ty of th e Apollo LES to je t t i son under nom inal launch cond i t ions w a s v e r i f i e d d u r i n gthe Apollo AS-101 and AS-102 m iss i on s . The r em a in in g s ix Apollo spacec r a f t abo r t

T A B L E 111. - APOL LO LES QUALIFICATION FLIGHTSMiss iond esigna t ionP A - 1A- 001AS-101AS- 10 2

A- 002

A- 003

P A - 2A- 004

Spacec ra f tBP- 6B P - 1 2B P - 1 3B P - 1 5

B P - 2 3

B P - 22

B P - 2 3Asc-002

Desc r ip t ionFirst p a d a b o r tT r a n s o n i c a b o r tNom ina l l aunch ande x i t e n v i r o n m e n tNom ina l l aunch ande x i t e n v i r o n m e n tMaxim um - dynam ic -p r e s s u r e a b o r tLow-a l t i t ude abor t(planned high-

a l ti t u d e a b o r t )Second pad abortPower -on tum bl ingb o u n d a ry a b o r t

Launch da teN o v e m b e r 7, 1 9 6 3May 13, 1964May 28, 1964S e p t e m b e r 18, 1 9 6 4

D e c e m b e r 8, 1 9 6 4

M a y 1 9 , 1 9 6 5

Ju ne 29, 1 965Jan ua ry 20, 1966

~~

Launch site(a )

WSMRWSMRKSCKSC

WSMR

WSMR

WSMRWSMR

%SMR (White Sand s M iss i le Range , New M exico) ; KSC (John F. Kennedy Sp aceCente r , F lo r ida ) .

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test f l i g h t s w e r e c o nd u c te d t o e x a m i n e t h e p e r f o r m a n c e o f . th e A p o llo s p a c e c r a f t a n d t heLES u n d e r c o n d it i o n s t h a t w e r e n o t e x p e c te d d u ri n g n o r m a l m an n ed m i s s i o n s . T h ea b o r t p o i n ts f o r S a t u r n l a u n ch - v e h ic l e f l i g h t s a r e s ho w n i n fi g u r e 1 3 w i t h t h e r e s u l t sof the abor t - typ e f l igh t tests.

Fl ight data fo r the Apol lo A-004 miss ion are t yp i ca l of t he de t a i l s t ha t w er e con -s ide red i n t he f l igh t - t e s t p rog ram . The Apollo A-004 m i s s ion t e s t po in t w as l oca t edwi th in t he r e g ion of t he power -on t umbl ing boundary . The boundary pos it i on w a s basedon t he s t ruc tu r a l - l oad capab i l it y of t he Apo llo spac ec ra f t and on the a l t i tude and veloc-ity at which t he l aunch es cap e veh i c l e cou ld be a l lowed to t umble du r ing t he power -onphase of the ab o r t w i thou t undergo ing g rea t e r - t ha n -de s ign - l im i t l oads . The de t e rm ina -t io n of s t r u c t u r a l l oa d in g w a s b a s e d o n th e l o c al p r e s s u r e d i f f e r e n t i a l a c r o s s t h e CMe x t e r i o r w a l l. T h e p r e s s u r e d i f f e r e n t ia l w a s c a u s e d by th e d i f fe r e n c e b e tw e e n t he i n -t e r n a l c a v i t y p r e s s u r e a nd t h e co m b in e d e x t e r n a l e f f e c t s of t h e a e r o d y n a m i c p r e s s u r eand p lume imp ingeme n t of the l aunch -escape mo to r . The Apo llo spa cec ra f t des ign -l i m i t l o a d f o r t h i s c o nd it io n w a s 11.1 ps id .

An expanded view of the Apollo A-004 mission test r eg ion is shown, in f ig ur e 14 .T h e test r e g i o n is bounded by the predic ted Li t t l e Joe I1 l aunch -veh i c l e max imum- andm i n i m u m - p e r f o r m a n c e t r a j e c t o r i e s a nd by a n a ll ow a b le p r e s s u r e d i s p e r s i o n of*1 . 5 p s id . Wi th nom ina l pe r fo rm anc e of t he LEV, a d i f f e r e n t i a l p r e s s u r e of a p p r o x i -mate ly 11 . 8 p s id w as p red i c t ed du r in g t he ac tua l ab o r t of t he Apo llo A-004 m i s s ion .T h e p l u m e - i m p i n g e m e n t p r e s s u r e d a t a th a t w e r e u s e d in th e m i s s i o n d e s i g n w e r e a p -p r o x i m a t e d f r o m d a t a ta k e n i n w i n d -t un n el t e s t s . T h e a p p r o x i m a t i o n w a s b a s e d o n th ea s s um p t io n t h a t t h e i m p i ng e m e nt p r e s s u r e s w e r e a d i r e c t f un c t io n of f r e e - s t r e a md y n a m i c p r e s s u r e a nd t h e r e l a t io n s h i p b et w ee n p l u m e a n d f r e e - s t r e a m m o m e n t u m .

ActualtestpointNumbers in parentheses oare altitudes i n thousand Af ee l 0

000

- lannedlestregion E- -001 IBP-121A-OOZ(BP-23)lIIIIIIIIID A-003IBP-22)0 -WISC-002)0 PA-1 IBP-6)0 PA - 2 IBP-23A)

Nominal Saturn Y

00Dynamic pressure, lbfftL

Little Jo eJI aximum

-Saturn envelope

\ /-Little Joe II minimumperformance boostCM pressure loading, psid Note: Differential Pressureestimates based onSat urn envelope nominal LEV.0 performance

1 I 1 I J

Dynamic pressure, lbff12450 500 55 0 600 650 m 75 01.8

F i g u r e 1 4 . - Test r e g i o n a n d a b o r tpo in t s fo r t he Apo llo A-004mis s ion .F i g u r e 1 3 . - Miss ion -abor t po in t s i nre l a t i on t o S a tu rn l aunch -veh i c l ef l i gh t enve lope .

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CONCLUDING REMARKSI n r e v ie w in g t h e f a i l u r e s t h a t w e r e e n c o u n t e re d d u r i n g th e d e v e l o p m e n t a n d q u a l i -f i ca t i on of t h i s s u b s y s t e m , it can be se en t ha t adequa t e de f in it ion of b o th s y s t e m a n dtest r e q u i r e m e n t s w i th p r o p e r i n s p e c ti o n b e t w e e n tests would have el iminated all fail-u r e s e x c e pt the t o w e r - j e t t i so n m o t o r i n t e r s t a g e f a i l u r e . E v e n t h i s f a i l u r e c ou ldp robab ly have been avoided wi th adequa t e f ab r i ca t i on p ro ced ure de f in i t ion and on - the -s p o t , r e a l - t i m e in s p e c ti o n .

Manned S pacecra f t C en t e rNa tiona l A erona u t i c s and S pace Adm in i s t r a t i onHouston, Te xa s, O cto be r 24, 1972914-11-00-00-72

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Apollo Experience Report Launch Escape Propulsion Subsystem