Juno Ii Fact Sheet d396w

NATIONAL AERONAUTICS AND SPACE ISTRATION WASHINGTON 25, D. C.

February 28, 1959 dold for Release Until Launched o r Indefinitely Delayed

No. 2

JUNO I1 FACT SHEET The Juno I1 carrier rocket used in the U. S , space probe experiment is based upon the Army-developed JUPITER Intermediate Range Ballistic Missile.

The rocket consists of a modified JUPITER

serving as the first stage and a three-stage cluster of solid propellant rockets placed in a spinning tub mounted in the nose o f the first stage, -

The rocket is 76 feet long and weighs about 60 tons o r 120,000 pounds when fueled, Main Stage Propulsion The JUPITER booster was modified for this special space role

to increase fuel capacity, Fuel for the booster propulsion system is a high grade kerosene; oxidizer is liquid oxygen. The vehicle's tank area begins at a point above the space occupied by the thrust unit, Bulkheads separate the engine compartment from the liquid oxygen tanksJ these tanks from the fuel tanks, and the fuel tanks from the instrument compartment at the upper end of%he

first stage. The smooth outer shell of' the JUPITER booster is also the inner

wall of the storage tanks, It is fashioned from aluminum alloy rolled from flat sheets,

A bell-shaped thrust chamber is used to combine high altitude efficiency with maximum performance at low altitude, The chamber is gimballed to allow use of the engine exhaust stream in controlling

- 2 -

directlor?, f G r

To provide c o o l i n g f o r t h e chamber d u r i n g o p e r a t i o n , f u e l

t h e engiile c i r c u l a t e s through t h e chamber w a l l s b e f o r e being f e d

ti-lrough t h e i n j e c t o r i n t o t h e combustion a r e a . Upper St ages The upper s t a g e s of t h i s launching v e h i c l e were o r i g i n a l l y developed for t h e JUPITER-C by NASA’s J e t P r o p u l s i o n Laboratory. ‘l’he up2er assembly i s f i t t e d i n t o a r o t a t i n g “ t u b 1 ’ o r l a u n c h e r , ruhdsh g i . ~ e ss ’ c a b i l i t y i n p o s t - s e p a r a t i o n f l i g h t , much a.s a r i f l e 2.3 s t a b : i l l z e d by s p i n n i n g .

b;r.ilet G ~ I a.

%:a=.ir?g.

Below t h e b e a r i n g and forward o f t h e first s t a g e

~,u;!.nnt.cornpzrtment . ,

m c ! . .~..;s cl.us:;er

The base o f t h e t u b i s moxnted

e l e c t r i c motors which s p i n the bucket

oi” r o z k e t s up t n 750 RPM,

Spinning i s initiate-d

;Iy Sefor;e l : i _ f t c ! f f and i s g r a d u a l l y i n c r e a s e d i n speed..

T!;e C - ~ X Lciy ~

‘72 I

5: 3.c:1 1

.?&slrilo:~ f o r m i n g a hollow c y l i n d e r

mxs 1.e

f’y.’?*:

secrjl-id s t a g e ccinsi.sts sf’11 s o l i d f u e l rocke-bs aligned iri

Weigh% of second s t a g e :

0

t ? i 4 r d s t a g e , w2ighing 207 poilnds,

c o n s i s t s of t h r e ? s o l i d

rc:cke’i;s pos.i-$iqned i n ’i;,.iangula::. f a s h i o n e q u i d i s t a n t f r o m c t.he1’: T h e t,l-;lrd s’czge si’c.s .I:? t h e c e n t e r of‘ t.he r i n g formed by t h e

::,ec~i,1;3.s t a g e m : i t o r s

A f t e r sec,ond. s t a g e ‘burnout, t h e t h i r d stage

i.gnit;es and pulls: o u t o f i t s encasement, !,?.!let h i r d a9d f o u r t h s t a g e s azd t h e instrumented payload con-

t i n ~ ~ ‘to r j s p i n ,.

- 3 T h e f o u r t h s t a g e i s a s i n g l e rocket motor weighing 59 pounds,

When it burns o u t i t i s s e p a r a t e d f r o m t h e probe itself' by a s m a l l ex>ios_i_re charge and s ? r i n g ,

which push t h e payload ahead of i t . Shroud

A z?ecia:Ly-designed

shroud e n c a s e s t h e launching v e h i c l e ' s

kig?:-ss;;c?ed upper assembly and payload.

fur:ctions::

The shroud h a s three main

to p i m t e c t t h e assembly from t h e h e a t g m e r a t e d by a i r

f i o w .+-':7ist,ioi?; to elirniiyate t h e dynamic f o r c e s to which t h e upper

s';al;es

ihjCVld.

o'sk?,.rwise be s u b j e c t e d ; and to provide s u p p o r t for the

a ~ o w - l i k eangle-of'-attaclc meter which I s r e q u i r e d i n thls n.

con!. z g u r a t i o n to gLve adecjmte c m t r o l d u r l n g i n r t i a l s t a g e s ol" 1' 2- :i

' I 0

Guidance ri-

J..%?

and c o n t r o l systems a r s l o c a t e d i n t h e forward

gt;ida:ce

uor$lon of' t h e f i r s t s t a g e and provide t h e o n l y source of' guidance ~~2fl;c::Li-t'tof'f .,

i. :.::

T!ie m i s s i l e must " t h i n k " for i t s e l f a x l a , d j u s t to

ei>TiT-i:PdkX1egt.

The orLLy grouzd-to-rocket

contyol i s t h e d e s t r u c t

a y a t c m ?i.ristallec! f o r range s a f e t y , '?'he 21.u:~ 12's guidance and c o n t r c l equi9ment I s a l s o enployed ?-:2

'L?..ccXii?lTER III13M,

It is a h i g h l y a c c u r a t e system known a s

The hear5 o f the d e v i c e is known as a s t a b i l i z e d - platform, sti

named because, through the use o f gyroscopes, it remains i n a

s t a b l e position d u r i n g t h e e n t i r e f l i g h t .

r'ri r i n g Procedure

- 5 predetermined a n g l e .

A f e w seconds a f t e r c u t o f f , t h e b o o s t e r

(combined t a n k and engine s e c t i o n of f i r s t stage) i s s e p a r a t e d

f r o m t h e i n s t r u m e n t compartment by t h e i g n i t i o n of e x p l o s i v e bolts.

Wrapped around t h e b o l t s a r e c o i l s p r i n g s ,

When t h e

e x p l o s i o n s d e s t r o y t h e b o l t s , t h e s p r i n g s e x e r t a g e n t l e push on t h e i n s t r u m e n t compartment and s e p a r a t e i t c l e a n l y from t h e b o o s t e r . T h i s i s followed by t h e f i r i n g of f o u r s m a l l l a t e r a l k i c k r o c k e t s

c o n t a i n e d i n t h e b o o s t e r which cause t h e b o o s t e r t o slow down and move t o t h e s i d e ,

T h i s e l i m i n a t e s any p o s s i b i l i t y of the

b o o s t e r i n t e r f e r i n g w i t h t h e f l i g h t of t h e s e p a r a t e d upper s t a g e s . The b o o s t e r f a l l s t o t h e e a r t h , while t h e upper assembly

c o n t i n u e s on i t s t r a j e c t o r y , ne minute.

The upper element c o a s t s f o r n e a r l y

The nose cone o f t h e shroud i s removed by e x p l o s i v e

b o l t s and s p r i n g s , and a l a t e r a l k i c k r o c k e t moves it t o t h e side.

S h o r t l y a f t e r t h i s , t h e second s t a g e of t h e r o t a t i n g

upper assembly w i t h i n t h e shroud i s i g n i t e d .

The assembly, now

r o t a t i n g a t about 550 RPM, r a p i d l y p u l l s o u t o f t h e shroud, and t h e t h i r d and f o u r t h s t a g e s a r e f i r e d i n q u i c k sequence.

After

t h e f o u r t h s t a g e b o o s t s t h e p r o b e ' s v e l o c i t y t o n e a r l y 25,000

m i l e s p e r hour, t h e burned-out motor c a s e s e p a r a t e s , l e a v i n g t h e i n s t r u m e n t e d payload t o c o n t i n u e i t s j o u r n e y i n t o s p a c e ,

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