AI AA-88-2622 A Method for Correlating the Diameter and Concentration Effects on Friction and Heat Transfer in Drag-Reducing Flows Hyung K. Yoon and Afshin J. Ghajar, School of Mechanical and Aerospace Engineering, Oklahoma State University, Sti I Iwater, OK

AlAA THERMOPHYSICS, PLASMADYNAMICS AND LASERS

CONFERENCE JUN€ 27-29, 1988/San Antonio, Texas

For permission to eo or m ublirh, contact the American Institute of Aeronautics and Astronautics "h r t n b n t h m e n d e , s.w., Wwington, D.C. 20024

A METHOD FOR CORRELATING THE DIAMETER AND

CONCENTRATION EFFECTS ON FRICTION AND

HEAT TRANSFER IN DRAG-REDUCING FLOWS

Hyung K. Yoon* . and Afshin J. Ghajar**

School of Mechanical an Aerospace Engineering

Oklahoma State University

Stillwater. Oklahoma 74018

c

P

DR

f

f P

f s

Nomenclature

c p r c i f i c hcac 3 f f l u i d

i n s i r i e diirnet,cr. of test . scct i im

dvag r,cductiL>,n v a n i o , D R :: f !f

f r i c c i o n fact.or, f = iK/(O$/?)

f v i c t i o n f a c t o ? fo!. polymer solution

f v i c t i o n f a c t o r f o r so lven t (Neutoniar

P S

V a l u e )

P r e s e n t a d d r e s s , Korea I n s t i t u t e of Ener'gy and

* * Associate Professoi, Member A I A A . R ~ S O U P C ~ S , Daejeon, Chungnam, Korea.

copyr igh t @ 1988 by rile hprnnaur,cs and i i .rroraurics . Lnc. M I Righre * s e w e d . 1

Rmrican lnsrlfufe O f

h e a t tr 'ansfer ' c o e f f i c i e n t

h e a t tvansfer ' reduc t i on r a t i o ,

tiri = ? h , p / j h , s

~ n ~ b u r ' n j-fact.or., jh = st. ~ r $ / 3

c o l b w n j - f a c t b r for. polymer s o l u t i o n

COI ~ u r ~ j - f ac'ror f OP sol ven t (N ewt,!,n i m

v a l u e )

ther,mal c o n d u c t i v i t y

l e n g t h of t e s t s e c t i o n

appa ren t Pvandtl number, Pva = n,c/k

a p p a r e n t Reynolds number, Re, = pUD/na

Stanr ,on number', St = h/pCU

average v e l o c i t y

appar'ent v i s c o s i t y a t t h e wall

f h i d t ime sca le

chwaCtCl . iSt iC f r e q u e n c y , see e q u a t i o n ( 1 )

f l u i d dens i cy

w a l l shear SCl'eBs

Introduction

It has been k n o u n t h a t t h e c h a r a c t e r i s t i c s of

polymer' s o l u t i o n s can be a f f e c t e d by s e v e r a l

factnrs such as p ipe diameter, polymel' -

c o n c e n t r a t i o n , s o l v e n t Chemistry, polymer

d e g r a d a t i o n , and t e m p e r a t u r e dependent f l u i d - p r o p e r t i e s . The focus of t h i s s t u d y i s on t h e

p ipe d iameter and polymer c o n c e n t r a t i o n e f f e c t s ,

which s h o u l d be known i n order' t o improve our'

a b i l i t y t o p r e d i c t t h e behavior of drag- reducing

polymer a d d i t i v e s i n p r a c t i c a l i n d u s t r i a l

a p p l i c a t i o n s .

To a d d r e s s t h i s o b j e c t i v e , exper iments were

Conductcd w i t h an a t tempt t o minimize t h e

i n f l u e n c e of s o l v e n t c h e m i s t r y , polymer

d e g r a d a t i o n , and tempera ture dependent f l u i d

p r o p e r t i e s on t h e polymer' s o l u t i o n s . T h i s was

accomplished by t ising t h e same kind of t a p water.,

and t h e once-through mode of o p e r a t i o n , and

m a i n t a i n i n g a small wal l - to-bulk t e m p e r a t u r e

d i f f e r e n c e . Thei'efor'e, t h e exper imenta l r e s u l t s

can bc C h a r a c t e r i z e d by t h e p ipe d iameter and t h e

polymei' c o n c e n t r a t i o n . A few a t t e m p t s have

been made t o c o r r e l a t e t h e f r i c t i o n f a c t o r d a t a

o b t a i n e d for' d i f f e r e n t p i p e d i a m e t e r s and/or

polymer' c o n c e n t r a t i o n s by a s i n g l e e x p r e s s i o n OP

curve. Amongst them, t h e method of A s t a r i t a e t

al. is t h e o n l y method t h a t e f f e c t i v e l y

1-5 -

COl'i'elates t h e CffeCtS Of p ipe d iameter and

polymer' Concent ra t ion . Howevei-, t h e method is

s t u d y , t h e c a r v e l a t i o n method proposed hy A s t a r i t ?

e t a1.' for' d r a g ? e d u c t i o n is a p p l i e d t o t h e

cur ' rent expevimental d a t a for' f u r the r ' v e r i f i c a t i o n

of i t s genei'al a p p l i c a b i l i t y , and t h e methLid i s

l o g i c a l l y extended t o t h e case of h e a t t r ans fe r '

r e d u c t i o n .

Experiments

The p r e s e n t exper'iments were conducted i n t h e

f l u i d dynamics l a b o r a t o r y a t Oklahoma S t a t e

Univer , s i ty . A schemat ic diagram of t h e flow

c iPcula t , ion system I s shown i n F i g u r e 1 . The t e s t

S e c t i o n s used have i n s i d e d i a m e t e r s of 1 .88 cm

(L/D i 617) and 1 . 1 1 C m ( L / D = 1 0 4 6 ) . These t e s t

s e c t i o n s ensuve t h e t h e r m a l l y f u l l y developed

c o n d i t i o n f o r YiSCoelas t ic f l u i d s which require

400 t o 500 d i a m e t e r s f o r t h e minimum h e a t t r ans fez ,

asymptote .6 To minimize mechanical d e g r a d a t i o n of

polymer s o l u t i o n s , t h e overal l flow sys tem was

o p e r a t e d w i t h pressuviaed a i r (up t o 80 p s i E )

u s i n g t h e once-through mode. The c o n s t a n t h e a t

f l u x b o u n d x y c o n d i t i o n was main ta ined by a

L i n c o l n DC-600 welder . I t can o p e r a t e i n t h e

c o n s t a n t v o l t a g e or c o n s t a n t c u r r e n t mode, and has

a 100% duty c y c l e r a t i n g at 600 amps and 4 4 v o l t s .

I n t h e p r e s e n t flow sys tem, e i t h e r t h e

w c S E c n u l l i m i t e d t o s l i g h t l y non-Newtonian l i q u i d s . In

t h e i r method, t h e f r i c t i o n f a c t o r d a t a f o r f i v e

c o n c e n t r a t i o n s of aqueous s o l u t i o n s of ET597 and

t h r e e p i p e d i a m e t e r s were COrPelated by a s i n g l e

Curve r e l a t i n g two dimenSionleSs p a r a m e t w s Which

were o b t a i n e d fr.om a phenomenological a n a l y s i s of

t h e mechanism of d r a g r e d u c t i o n . However, as far.

a s t h e h e a t t r ans fe r ' d a t a is concerned , a method

f o r c o r r e l a t i n g t h e e f f e c t s of' p i p e d iameter and - polymer c o n c e n t r a t i o n is not a v a i l a b l e . I n t h i s ~ i g . 1 Schematic diagram of t h e flow c i r c u l a t i o n system .

2

. I l "

Nowt,oiian c o r i e l a c i o n s . The u n c w t a i n t y

analyses sf t h e over'all expet ' inenta l pracedur'es

fa' Newt,3nian and v i s c o e l a s t i c f l u i i i s showed t,hat

theve is 5 4 % u n c e r t a i n t y for' f r ' i c c ion f a c t o r s a n d

8-12s u n c e r ' t a i n t y for' h e a t t l 'ansfer '

c o e f f i c i e n t s . Move d e t a i l e d desc t ' ip t ian of che

experimental appar 'atus and procedur~es ape

p resen ted elsewher'e. I !

For t h i s pa r ' t i cu l a r S tudy , Lhe Choice O f Chi

V i s c o e l a s t i c f l u i d t o be used was l i m i t , & t o

s1 i g h t l y nm-Newtonian 1 i q u i d s . For t h i s p u i ' p o s c

t h e se l l -mixe l l homogeneous aqueous So1Ut.iims O f

po lye thy lene Oxide ( P n l y o x WSR-301) w i t3

Concen t r a t ions of 100, 300, and 500 ppn ~ f : l c

used. The appa ren t v i s c o s i t y 3f each ~olypl r r '

s o l u t i o n at wide range of shear' r a t e s 'was m

a n d t h e r e s u l t s cOnfirmeii t h e s l i g h t l y m n -

Newtonian character . of C h e x s o l i i t i o n s . F W C ~ W

d e t a i l s l i h y be f o u n d elscwheve. I I

The measur'ements of pvessure drop and ?cat.

tr 'ansfer ' w e p r c s c n t c d i n terms of f i ' i c t i v n fac tor '

and Colbul'n j - f a c t o r i n r igu i ' es 2 and 3 ,

r ' e spec t ive ly . IT. i s observed from these figur 'cn

c h a t t h e r 'eductinn i n f r ' i c t i o n f ic t .ors and b a r .

t v a n s f w c o e f f i c i e n t , s f x the srnal le i J ipn ( 1 .11

cm test . s e c t i o n ) i:; inoi'e pvonounccd t h a n t h a t ?x

t h e lar'ger' one (1 .88 Cm t es t s e c t i o n ) . Th i s C a l l

he exp la ined by t h e following i n t e rp r ' eca t ion : t hc

L polymer, molecules a r e COnsider'ed t.0 i n f l u e n c e thi i

boundary layet' c l o s e to t h e p ipe w a i l . T h i s

i n f l u e n c e S h i u l d be seen i n t h e smaller p i p e

b e f o r e t h e l a r g e r one s i n c e t h e b o u n d a r y laye!'

would form a lar'ger' p o r t i o n of t h e t o t a l flow i n

t h e s%ail p i p e . h compai'ison of Figul 'es 2 and 3

a l s o byings o u t t h e f a c t t h a t an i n c r e a s e i n t h e

polymer c o n c e n t r a t i o n r e su l t s i n a decr 'easc i n t h e

f r i c r i o n fac tor . and t h e heat t r ans fe r ' j h f a c t o v .

Fur'thevmare. t h e reduct, ion i n h e a t t.r'ansfer i s

g e n ~ a l l y g r e a t e r t h a n t h e reduc:ion i n thi!

f r i c t i o n f a c t o r r e l a t i v e t o t h e i r ' Newtonian

t u r b u l e n t values.

I *

Correlation Method POI' Drag Reduction

To account f o r t h e e f f e c t of p ipe d iameter on

dvag veduc t ion , Astat ' i ta e t a l . used t h e v

10-2,

t I 10-3

Rea Fig . 2 F r i c t i o n f a c t o r vs. a p p a r e n t Reynolds

number for Polyox WSR-301 SolUtiOnS i n t h e 1.88 and 1 . 1 1 em t e s t s e c t i o n s .

10-

10-

, - 0 . 0 1 5 5 R ~ ~ ~ ~ " P r ~ ~ ~ ~ ' ~

*.

104

Roe Fig . j Colburn j - f a c t o r VS. a p p a r e n t Reynolds

number' for' POlyOx WSR-301 s 0 1 U t i O n s i n t h e 1.88 and 1 . 1 1 Cm t e s t s e c t i o n s .

c h a r a c t e r l s t i c f requency (6l) proposed by Seyer and

Metzner: I ,

T h i s r e l a t i o n s h i p for t h e c h a r a c t e r i s t i c f requency

was o b t a i n e d from a phenomenological a n a l y s i s of v

t h e mechanism of d r a g r e d u c t i o n : t h e d r a g

r e d u c t i o n is observed o n l y a t t h e wall s h e a r

stress exceeding t h e c r i t i c a l v a l u e o f s h e a r

s t r e s s . F u r t h e r a t t e m p t was made t o c o r r e l a t e t h e

f r i c t i o n f a c t o r d a t a for d i f f e r e n t polymer

ConCentPations. From t h e d imens iona l a n a l y s i s , i t

was concluded t h a t t h e f r i c t i o n f a c t o r should he a

f u n c t i o n o f bo th t h e Reynolds number and t h e

Deborah number. Astarita et al. assumed t h a t t h e

v a l u e of d r a g r e d u c t i o n r a t i o ( D R = S /f ) was

u n l q u e l y de te rmined by t h e Deborah number of flow:

P S

where A is t h e f l u i d t ime s c a l e . S i n c e t h e v a l u e

of A was not Unequivocal ly d e f i n e d i n t e rms of

measurable r h e o l o g i c a l p r o p e r t i e s f o r d i l u t e

S o l u t i o n s . t h e f o l l o w i n g a l t e r n a t i v e method was

proposed. Let no.5 be t h e f requency c o r r e s p o n d i n g

t o t h e d r a g r e d u c t i o n ra t io o f 0.5:

where X = no.5\ is a c o n s t a n t which , i f e q u a t i o n

(3 ) is v a l i d , does not depend on t h e p a r t i c u l a r

S o l u t i o n cons idered . Equat ion (3 ) can be w r i t t e n

i n t h e e q u i v a l e n t form:

where t h e measwable c h a r a c t e r i s t i c parameter

h a s been s u b s t i t u t e d f o r A . Equat ion ( 4 ) a c c o r d i n g

t o Astarita et a l . c o r r e l a t e s t h e d r a g r e d u c t i o n

d a t a fo r d i f f e r e n t polymer' C o n c e n t r a t i o n s and

d i f f e r e n t p i p e d i a m e t e r s by a s i n g l e c u r v e . I t is

t o be noted t h a t t h e c o r r e l a t i o n method sugges ted

by equal-ion (4) was Obtained from a

phenomeno: j g i c a l a n a l y s i s or t h e mechanism of d r~ag

IiedL1ction 2nd i s l i m i t e d t o s l i g h t l y non-Newtonian

l i q u i d s , 2s !nost dvag-,'educing d i l u t e palymet,

solucions ,? re .

I n 0:'der t o fui'che!' v e r i f y t h e g e n e r a l

a p p : i c a b i l i S y of t h e cor'r 'elation method pr'oposed

by R s t a v i c a e t a l . , i t was a p p l i e d t3 t h e Current.

eXi)el'imen:al f r ' icLion fac tor ' da:a for' P o l y o x wsn-

301 S o l u t i o n s ( see F'igur'e 2 ) . Figur'e 4 shows p l o t

of t h e exper imenta l d a t a i n t e rms of t h e d r a g

r'eaucr.ion r 'acio v s . t.he C h a r a c t e v i s t i c f w q u e n c y .

The diameter' e f f e c t seems t o have been adequare ly

t aken i n t o a c c o u n t . I n or'aer t o account for. t h e

ef fecrs of both t h e pipe d iameter and t h e polymer

c o n c e n t r a t i o n , t h e d a t a r e p o r t e d i n F lgu re 4 have

been Dlocted i n She form sugges ted by e q u a t i o n

O l ) , see F i g u r e 5. T h i s figui'e i n d i c a t e s t h a t t h e

f r i c t i o n a a t a can be c o r r e l a t e d by a s i n g l e curve,

independent of t h e p ipe d iameter and t h e polymer

Concent i ia t ion. ,It should be noted t h a t i n t h i s

s t u d y , a dr'ag r 'educt ion r'atio of 0.3 was used

i n s t e a d of' 0.5 employed by A s t a r i t a e t al. T h i s

sugges t s cha t any c o n s t a n t va lue of d r a g ? e d u c t i o n

r a c i o can be used i n c o r r e l a t i n g t h e f v i c c i o n

fac tor ' d a t a . As fat' a s t h e l o g i c a l e x t e n s i o n of

c h i s method t o t h e case of hea t t ransfer ' r e d u c t i o n

is concerned , c h i s is an encouraging r l e su l t s i n c e

h e a t t r a n s f e r . r e d u c t i o n r a t i o is much lower. t h a n

t h e d r a g ? e d u c t i o n r a t i o .

Correlation Hethod for Heat TransPer Reduction

Since the Onset of t r a n s i t i o n for both

momentum t r ans fe r , and hea t t r ans fe r ' was obser'ved

t o occur s i m u l t a n e o u s l y a t Re, 5500, i t is

expec ted t h a t t h e c r ' i t i c a l values o f s h e a r stress

I ' t , l 5 ,

0 1.1 1 cm 10-11 I I

300 PPM

10-1

1 1

0-7 05 lo6 3x106

n Fig. 4 Drag r,eduction r a t i o vs. c h a r a c t e r i s t i c

f requency f o r Polyox WSR-301 s o l u t i o n s i n t h e 1.88 and 1 .11 cm t e s t s e c t i o n s .

t

w

W

n'n0.3

F ig . 5 S i n g l e cur've C o r P e l a t i o n of f r i c t i o n f a c t o r d a t a .

a r e approximate ly t h e same for, bo th cases. l h i s

i n d i c a t e s t h a t t h e c o r r e l a t i o n method fo r t h e dr~ag v

5

r e d u c t i o n can be a l s o a p p l i e d t o t h e case of h e a t

t r 'ansfer PedUCtion. I t is Suggested t h a t t h e

c h a r a c t e r i s t i c f requency f o r t h e hea t t r a n s f e r can

be a l s o e v a l u a t e d by e q u a t i o n ( 1 ) . I t is also

assumed t h a t t h e v a l u e O f heat t r ' ansfer I 'educt lon

r a t i o (HI? = j h , p / j h , s ) can be determined f?om an

e x p r e s s i o n similar t o e q u a t i o n ( 4 ) :

Whem Qc is t h e c h a r a c t e r i s t i c f requency e v a l u a t e d

a t certain c o n s t a n t v a l u e c of H R . Similar' t o t h e

drag ? e d u c t i o n case, a c h a r a c t e r i s t i c hear,

t r ans fe r . r e d u c t i o n r a t i o o f 0 . 3 was used.

The e x p e r i m e n t a l h e a t t r ans fe r , t ' e su l t s

p r e s e n t e d i n FigUI'c 3 are p l o t t e d i n t e rms of t h e

h e a t t r ans fe r ' r e d u c t i o n V S . t h e c h a r a c t e r i s t i c

f requency i n F i g u r e 6. From viis f i g u r e i t

a p p e a r s t h a t t h e e f f e c t of d iameter on t h e heat.

t r a n s f e r d a t a f o r each pavt icu lar ' polymer' s o l u t i o n

have been a d e q u a t e l y taken i n t o a c c o u n t . The

dependency of t h e d a t a r e p o r t e d i n FiguYe 6 On t h e

polymer' c o n c e n t r a t i o n can De e l i m i n a t e d by

r e p l o t t i n g i r . i n t h e form sugges ted by e q u a t i o n

( 5 ) . s e e F i g w e 7. This f iewe c l e a r l y

demonstva tes t h a t t h e h e a t transfer^ d a t a can be

co r , r e l a t ed by a s i n g l e Curve, independent of t h e

p ipe d iameter and t h e polymer COnCentPatiOn.

v

Conclusions

The g e n c r a l a p p l i c a b i l i t y Of t h e c o r r e l a t i o n

method developed by AStaPi ta e t a i . Far' drag

r e d u c t i o n was f u r t h e r v e r i f i e d w i t h our r e c e n t

exper imenta l d a t a for. Polyox WSH-301. Using the i r '

method, i t was shown t h a t t h e i n f l u e n c e o f p i p e - diameter. and polymer c o n c e n t r a t i o n on f r ' i c t i o n

100 PPM

HR

o 1.88 crn 0 1.1 1 cm I

HR 10-1 I \ , / 500 PPM ::Fj

10-1 105 106 3x106

h I1

F i g . 5 Heat tr'ansfet' veduccion i ' a t i o Y S .

c h a r a c t e r i s t i c f requency for Poiyox WSR- 301 s o l u t i m s i n t h e 1.88 and 1 . 1 1 CF t,.rsr, secr,ions.

1.0 , 1 I

0.81 0

HR

0

0

0

POLYOX WSR-301

300 I A 1 A 500 0

0.0 10-2 10-1 100 IO'

n'n0.3

F ig . 7 S i n g l e curve C o r r e l a t i o n of heat ti 'ansfer' d a t a .

f ac to r d a t a Can be c o r r e l a t e d by a s i n g l e c u r v e .

The method was extended and a p p i i c d t o our recent

h e a t tvansfer' d a t a . I t was Shown thac t h e

pr~gposed method a d e q u a t e l y a c c o u n t s f o r t h e

e f f c c t s of p ipe diameter' and polymer c o n c e n t r a t i o n

on h e a t t v a n s f e r d a t a and t h e I ' e su l t s can be a l s o

cor've1ateC by a s i n g l e curve. The r ' e s u l t of t h i s

s t u d y s u g g e s t t h a t t h e method is g e n e r a l and

Capable of c o r r e l a t i n g t h e e f f e c t s of p ipe

diameter' nnd polymer. concent r ' a t ion an both

f r i c t i i m faczor' and h e a t t r ans fe r ' d a t a . However',

i t sh:mId be r c n l i z e d t h a t t h e C o r r e l a t i o n method

is o n l y a D p l i c a b l e t o s l i gh t , l y non-Newtonian

s o l u t i o n s .

acknowledgment

T h i s work was p a r ' t i a l l y sponsored by t h e

Un ive r~s i ty Center for Enevgy Research ( U C E R ) a t

Oklahoma S t a t e U n i v e r s i t y .

1 .

2.

3.

4.

5.

6.

Rererences

Rodl'iquez, J . M . . Zakin, J . K . , and P a t t e r s o n , C . K . , " C o r r e l a t i o n of Dr,ag Reduct ion w i t h Modified Deborah Number for D i l u t e Polymer S o l u t i o n s , " S o c i e t y of Petrmleum Engineers J . , 1967, pp. 325-332.

A s t a r i t a , G . , Cl'eco, Jr., G . , and Nicodemo, L . . " A PhenornenoloPical I n t e r a r e t a t i o n and - C o r r e l a t i o n of Drag Reduct ion ," RIChE J . , Val. 15 , No. 4 , 1969, pp. 564-567.

G v a n v i l l e . P . S . . "Scalina-uD of PiDe Flow . . F r i c t i o n a l Data f o r Drag Reducing Polymer S o l u t i o n s ,(' Pvoceedings 2nd I n t e r n a t i o n a l Confer~ence on Drag Reduct ion, B r i t i s h Hvdl'omechanics Research A s s o c i a t i o n . Cambridge, U K , 1974, paper' 83.

S e l l i n , R. H . J . and O l l i s , M . , " E f f e c t of Pipe Diameter' on Polymer Drag Reduct ion ," Ind . En&. Chem. Prod. Res. Dev. , Yol. 22, 1983, pp. 445-452.

Dar'hy, R . and Chang, H . D . , "Gener.alized C o r r e l a t i o n far Fr ' ic t ion Loss i n Drag Reducing Polymer' S o l u t i o n s AIChE J., Vol. 30, 1984, pp. 274-280.

Kvack, E . Y . , Cho, Y . I . , and Har ' tne t t , J. P . , "Heat T r a n s f e r i n Polyacr'ylamide S o l u t i o n s i n Turbulent P ipe Flow: The Once- Through Mode." AIChE J., Vol. 27, 1981, Pp. 123-1 30.

~

7.

8.

9.

10.

1 1 .

12.

13.

1 4 .

15.

uays , w. M., Convect ive Heat and M ~ S S

T r a n s f e r , McGr'aw-Nil1 9001: Company, 1960.

V McAdams, W . H . , Heat Transmiss ion , McGt'aw- H i l l Rook Company, 19511.

A l l e n , R . W . and Eckevt , E. R . G . , "Frict.ion and Heat T r a n s f e r Measurements t o Tur'bulent Pipe Flow o f Watev ( P r = 7 and 8 ) o f U n i f o m Wall Heat F l u x , " J . Heat Tr'ansf'er~, Vo1. 86 , 1964, p. 301.

D i t t u s , F. W . and B o e l z e r , L. M. K . , "Heat Tr'ansfer~ i n Automobile Radiator 's of t h e Tubular ' Type," U. of C a l i f o r n i a P u b l i c a t i o n i n Engineer ing , Val. 2, 1930, p . 443.

Yoan, H . K . , "An Experimental and A n a l y t i c a l Study of Heat T r a n s f e r t o Polymer Solu t ions i n Turbulen t P i p e Flows Under' Cons tan t Wall Heat F l u x , " Ph.D. t h e s i s , Oklahoma S t a t e Univer>s i ty , 1986.

Hoyt , J . W., "The E f f e c t o f A d d i t i v e s on F l u i d F r i c t i o n , " T r a n s a c t i o n s of t h e ASKE, Vol. 94, June 1972, pp. 258-285.

Seyer , F. A . and Metzner , A . E . , "Tuvbulcnt. Flow Pr 'oper t ies of V i s c o e l a s t i c F l u i d s , " J . Chem. E n g . , Vo1. 45 , 1967, pp. 121-126.

Ng, K . S . , Cho, Y . I. and H a r t n e t t . J . P . , "Heat T r a n s f e r Performance of Concentr,ated Polye thylene Oxide and Polyacrylamide S o l u t i o n s , " AIChE J., Vo1. 26 , 1980, pp. 250- 256.

Ng, K . S . , H a r t n e t t , J . P. and Tung, T. T . , - "Heat T r a n s f e r of Concent ra ted Drag Reducing V i Scoelas t i c Pol yacr'ylarni de Sol u t i ons , I ' 1 7 th N a t l . Heat T r a n s f e r C o n f . , S a l t Lake C i t y , Utah, 1977.

Paper No. 88-2622 AlAA Space Programs and Technologies Conference June 21-24, 1988

SPACECRAFT TECHNOLOGY REQUIREMENTS FOR FUTURE NASA MISSIONS

Wayne R. Hudson Gordon 1. Johnston

For wtmlction to eo or re ubllsh, contact the Amerlwn lntmute of Aeronautltr; and AttmnauHu pr70 UPnhnt h m e n d e , s.w., Whington, D.C. 20024

SPACECRAFT TECHNOLOGY REQUIREMENTS FOR FUTURE NASA MISSIONS

Yayne R. Hudson' NASA Headquarters Washington. D.C.

Gordon I. Johnston.. Jet Propulsion Laboratory

Washington, D.C.

*Assistant Director for Space; Member AIAA **Program Manager for Spacecraft Systems Analysis; Hember AIAA

ABSTRACT

By working with advanced planners in the NASA Office of Space Science and Applications (OSSA), a spacecraft technology model has been generated that represents the predominant themes of their respective programs for the next twenty years. This set of missions serves as a base from which a feu representative and challenging landmark missions have been extracted to serve as a focal point for identifying the most critical technology issues. Each mission requires significant advances in several technology disciplines in order to be feasible. The mission set selected to serve as a technology focus reflects the increased emphasis within NASA on a potential civil space leadership initiative, and include the Geostationary Earth Observing Platform from the Planet Earth initiative and the precursor Mars Rover and Sample Return mission from the Mars Exploration Initiative. These missions are

requirements are discussed. - briefly described and the key technology

INTRODUCTION

The next twenty years will see dramatic increases in the use of space for scientific and applications missions, including missions in Earth science, space physics, astrophysics solar system exploration, and communications, as well as for commeroial and military purposes. These missions will advance our understanding of the Earth as a system; study the complex interactions between the sun and planetary magnetospheres; expand our understanding of the birth and formation of stars and stellar systems; continue to explore and characterize the planets in our solar system; search for evidence of planets around other stars; provide the crucial precursor missions to human expansion and exploration of' the moon and Hars; advance the state of the art for commercial satellites; and contribute to our continued leadership and security in apace.

In response to this evolving environment, the NASA Office of Aeronautics and Space Technology conducts systems analysis studies to identify key technology needs and opportunities, and to develop integrated technology plans and objectives. The results of these studies support the development and advocacy of technology thrusts and focused technology initiatives within the OAST Space Research and Teohnology program. The recent successful advocacy of the Civil Space Technology Initiative (CSTI) and Project Pathfinder drew heavily upon the results of the Systema Analysis program.

-

Efforts such as the joint NASA/bD Advance Launch System program w i l l result in reductions in the cost of access to space, and will lead to increased variety in the uses of space by NASA, the military, and the commercial sector. Future spacecraft will be diverse in nature as the variety of scientific and application missions inoreases. Some spacecraft, built for focused mission objectives, w i l l emphasize decreased size and mass, increased reliability, and simplicity of operation, relying on advances in technology to achieve these attributes. Such advances could include on-board fault detection and correction and on-board data processing capabilities. Other spacecraft w i l l seek to provide the next generation of in-space capabilities. Missions, such as multi-instrument Earth science platforms planned for both low and geostationary Earth orbit, will provide data from a suite of scientific instruments, and provide systematic and cross correlated data sets to address systematic and cross discipline Scientific questions. These spacecraft will require highly complex systems that will allow a wide variety of simultaneous activities, some requiring coordination and some requiring independence, with high reliability and reduced ground operations cost. These missions will produce data at extremely high rates and in massive amounts.

The increased capacity for in-space servicing of spacecraft will lead to increased demand for this service to enhance the reliability, increase the lifetime, and update the capabilities of on-orbit spacecraft. Future missions w i l l require the servicing and replacement of delicate soientific instruments, some of which may be cryogenically cooled. accessible by human-rated vehicles will require autonomous or telerobotic servicing capabilities.

Servicing of spacecraft in orbits not

MISSION MODn

To help direct the NASA OAST Space Research and Technology program, the future mission of the OSSA are incorporated into a mission model, shown in figure 1. This mission made1 is consistent with the OSSA strategic plan' and represents and ambitious and optimistic set of missions. The realities of funding constraints may not allow all of these missions to progress on the schedule shown.

The Space Research and Technology program recognizes both the requirements of future missions and the opportunities for new technology to enable missions beyond those in the mission model. Since it can take as long as twenty years

" h i e paper is declared a vprk.of the U.S. Government 1 and is not subject to copyright protection in the

United States."

?or a teohnology to transition from conceptualization to mission application, a projection of future mission needs is essential to

from the mission model have been selected for furthep study in order to identify critical enabling and enhancing technological needs. This selection reflects the growing interest in future NASA bold new initiative options, and emphasizes four areas: the Mission to Planet Earth; Robotic Exploration of the Solar System and Precursors for Human Expansion; Advanced Observatories; and Advances Spacecraft Technologies. Included in these efforts are studies of: the technologies required for Earth Science Geostationary Platform which form a key element of the proposed Planet Earth Initiative; the technology requirements for the Mars Rover and Sample Return mission, which is both a key element of the Robotic Solar System Exploration Initiative and an important precursor mission for human exploration of Uars; the technologies required for space based optical interferometers; and approaches to reduce total spacecraft cost that will apply to a broad variety of science and applications spacecraft including communications as well as commercial missions.

- aid in planning the program. Landmark missions

MISSION TO PLANET EARTH

The Mission to Planet Earth2 is an initiative to Understand our home planet, how forces shape and affect its environment, how that environment is changing, and how those changes w i l l affect Us. The goal of this initiative is to obtain a comprehensive scientific Understanding of the entire Earth System, by describing how its various components function, how they interact, and how they may be expected to evolve an all time scales. The challenge is to develop a fundamental understanding of the Earth as a system, and of the consequences of changes to that system, in order to eventually develop the capability to predict changes that might occur-either naturally, or as a result of human activity.

The guiding principle behind this initiative is the adoption of an integrated approach to observing Earth. The observations from various sensors on platforms and satellites will be coordinated to perform global surveys and to perform detailed observations of specific phenomena.

This initiative requires advances in technology to enhance observatians, to handle and deliver the enormous quantities of data, and to ensure a long operating life. Sophisticated sensors and information systems must be designed and devefoped, and advances must be made in automation and robotics (whether platform servicing i s performed by astronauts or robotic systems). Since the envisioned geostationary platforms would be lifted to lou-Earth orbit, assembled at the Space Station, and then lifted to geosynchronous orbit with a space transfer vehicle, well- developed orbital facilities are essential. The Space Station must be able to support on-orbit assembly, and a space transfer vehicle must exist.

The three missions that form the space segments for the Mission to Planet Earth are the low Earth polar orbit Earth Observing System (EOS)

v

1

platforms, the Earth System Explorer Missions, and the advan ed Geostationary Earth Science

complements of instruments contributed by NASA, NOAA, and other nations, will meet the operational requirements for weather and environmental prediction as well as the research objectives of Earth system science. The EOS, Explorer clasz missions, and advanced geostationary platforms will support NASA research and NOAA operational instruments. The design of the space segments should facilitate a smooth transition of instrument capabilities from the research environment through pilot projects to fully operational status, as well as assuring the maximum utility of data from all instrument to all users.

The first space segment, COS, is currently envisaged a3 being deployed in the mid-1990s. with growth in the number and quality of remote sensing capabilities through the year 2000 and beyond and operate at its full capability for ten more years. )"any of the crucial measurements would be obtained for a period of at 15 years. The EOS will establish the research capability of advanced instrumentation, such as high-resolution spectrometers, multi-channel radars, and space- based lidars. important new and improved Earth measurements, including mineral composition, land-surfacer vegetation, cloud properties, and the deformation of continental plates, as well as the measurement of atmospheric winds, aerosols, boundary-layer properties, and certain tract constituents. The extensive set of individual instruments in the EDS payload is required because of the different measurement capabilities needed to observe the various regions of the electromagnetic spectrum by passive and active remote sensing techniques. The presently developing 10s strategy, which reflects extensive international cooperation in many program aspects, calls for two U.S. platforms and one ESA morning platform in coordinated orbits.

The second space segment is a series of Explorer- class missions and the use of well established instruments mounted on long term platforms such as the Space Station. synergisms within EOS, there are some observing needs that require other low Earth orbit configurations or dedicated spacecraft. Notable needs in this category include measurements of the Earth's gravitational field from an orbit sufficiently low to yield adequate spatial resolution, measurements of the precipitation throughout the diurnal cycle with active microwave techniques, observations of the Earth's magnetic field using sensors isolated from electrical interference, and investigation of the properties of the thermosphere for which in situ sampling is necessary.

The third space segment of a total system for global Earth observation will be provided by advanced platforms in geosynchronous orbit. offer several fundamental advantages over other platforms. First, high temporal resolution, limited only by instrument design and cost, can be brought to bear on the study of rapidly changing, global atmospheric phenomena. Another major advanoe would be passive-microwave sensing of regions of precipitation. The capability Of

Platform s . These configurations, with

Such instruments will yield

In Spite of the powerful

These

/

2

microwave sounding is not now available because of the large antenna required for adequate spatial resolution at geosynchronous orbit altitudes. Geosynchronous orbit furthermore provides a fixed reference geometry for a given Earth location, facilitation data analysis and interpretation, Operational geosynchronous satellites have been in service since 1974 and carry imager/sounder instruments ppoviding high resolution visible and infrared images of the Earth. The infrared channels of the sounding instruments provide temperature and moisture profiles Over large areas of the Earth with high frequency. NOAA now operates two GOES geostationary satellites and w i l l continue to support the operational need for weather monitoring and prediction.

Earlier report^"^ have discussed the technology requirements for the EOS. These include utilities and servicing technology involving platform and servicing related needs, data systems technology including both in space and ground based data and information systems, the precision pointing and control technology needed to enable precise and coordinated multi-payload pointing control on- board the EOS platform, and instrument technology including advanced lasers, detectors, and cooling requirements. Advanced geostationary Earth science platforms share many requirements with EOS (Figure Z ) , including high voltage power systems, high throughput data and control systems, a capable thermal management system, and precision pointing and control to support the multiple scientific and operational instruments required by the mission. This report addresses the needs of

v

.- advanced geostationary Earth science platforms.

The energy required to access geostationary orbits limits the ability to perform servicing missions and will increase the importance of long life, increased reliability, and increased efficiency in the use of expendables. platforms will be too massive to return to low Earth orbit and there are no piloted vehicles currently envisioned that could access geostationary orbit, so any servicing mission will require robotic OP telerobotic capabilities. Even if initial geostationary missions are not designed to rely upon servicing, advanced and operational missions will depend upon servicing to repair, resupply, and upgrade the capabilities of the platform. These platforms w i l l require adaptable power, data/control, and thermal management capabilities to provide the flexibility for these future upgrades, as well as instrument and subsystem designs incorporating serviceability. An on-board robot or telerobot designed for the specific environment of the platform would simpUfy servicing design requirements. Accurate ground models of the platform, instruments, and subsystems will be required to enhance development, integration, and to verify growth possibilities. Servicing missions could use aerobraking in the Earth's atmosphere for the return from geosynchronous orbit to reduce the mass and fuel requirements.

The platform will require on-board processors capable of handling the high data rates and large data volumes generated by the multiple scientific and operational instruments. This data system will require an "open" architecture employing local area network management to support

Advanced geostationary

-

additional instrument and system upgrades as a result of servicing. However, the nature of geostationary orbits will greatly simplify the data communications requirements, with large dedicated ground stations providing the needed telemetry capability without interruption. In the area of on-board data storage the geostationary platform less demanding than the low earth orbit EOS.

Although the requirements for data systems technology are less stringent for advanced geostationary platform than for the EOS, the requipements for precision pointing and control technology are more stringent. of geostationary orbits for Earth observing platforms is the ability to acquire continuous observations with high temporal resolution. As show in figure 3 , Earth systems processes which require high temporal resolution observations tend to require high spatial resolution. Despite the substantially greater altitude of geostationary orbits ovep the orbits of the EOS and the Explorer class missions, the phenomena observed require the highest possible spatial resolution. This in turn places greater requirements foor precision pointing and platform control. Large precision antennas are required in order to acquire microwave sounding with adequate spatial resolution from geosynchronous orbit altitudes. As shorn in figure 4, observations, at 36 GHz with an Earth footprint of 10 kilometers require an antenna diameter of 40 meters. This large antenna will require precision shape corpection and steering to allow coverage of the globe, either mechanically or through receiver array adjustments. pointing requirements of other precision instruments on the platform require that this large antenna not dominate the dynamics of the entire platform. The need to decouple the motions of these structures may require novel solutions such as tethered platforms or a network of free flying spacecraft.

The instrument technology requirements for advanced geostationary platforms are analogous to those of the EOS, with the exception that aotive sensing using radar or lidar is not planned due to the high output power required to obtain adequate return signals. Precise geodesy measurements using laser sources on the geostationary platform and Earth based retroreflectors may be conducted. Future advances in spacecraft power and radar and laser source efficiency may allow future consideration of' active sensing from geostationary orbit.

Many of these technology requirements for advanced geostationary platforms are addressed by OAST technology programs including the Civil Spaoe Technology Initiative (CSTI) initiated this year and the Project Pathfinder technology initiative proposed for initiation in fiscal year 1989. includes program elements in automation and robotics; sensors; on-board data processing and storage; large structures and control; and aerobraking (for servicing vehicle return). Pathfinder will develop technology options for potential Agency bold new initiatives including the Planet Earth initiative, and includes program elements in optical communications; autonomous rendezvous and docking; in-space assembly and construction; and fault-tolerant systems.

A major advantage

The

CSTI

3

ROBOTIC SOLAR SYSTEM EXPLORATION/ PRECURSORS FOR HUMAN EXPANSION

The Robotic Solar System Exploration' initiative would build on NASA's longstanding tradition OF solar system exploration and would continue the quest to understand our planetary system, its origin, and its evolution. The centerpiece of the initiative is the robotic exploration of Mars, with the Mars Rover and Sample Return (MRSR) mission (Figure 5). In'addition, the MRSR mission would serve as an important precursor to the Humans to Mars' initiative. This initiative is committed to the human exploration and eventual habitation OF Mars. Robotic exploration of the planet would be the First phase and would include the return of samples of Martian rocks and soil.

In cooperation with the OSSA Solar System Exploratign Division, OAST has onducted

technology requirements for Mars rover and sampling missions. Return mission will require technology developments to support key functions including: rover mobility and local navigation; sample acquisition, analysis and preservation; operations automation; computation and data handling; rover and lander power; thermal control; communication; aerobraking; parachutes; landing hazard avoidance; and rendezvous and docking. The unknown and uncontrolled environment of Mars, coupled with the inability to directly control rover at Mars due to light-time delays, makes artificial intelligence an essential technology far accomplishing the

u

workshops and produced reports ? summarizing the The Mars Rover and Sample

* mission goals.

The boulder strewn Surface of Mars as revealed by the two Viking landers presents major challenges in rover mobility and local navigation. The principle technology requirements are in mobility mechanisms, sensors, control systems, route and path planning, execution monitoring and reaction, surface property determination, and three dimensional modeling. Sample acquisition, analysis, and preservation will require technology developments i n sample identification and location, sample acquisition, non-intrusive processing and packaging, and sample analysis.

A critical Factor in mission capabilities is the ability of the mission operations team to command the Rover during planetary operations. Previous planetary missions have requlred months to generate and validate spacecraft command sequences. Operations automation will require the development of a rover system exeoutive, up-link generation tools, and simulators for surface operations and the rover system executive. The compztation and data handling Functions of the mission will require developments in fault tolerant multiprocessors, image processing architectures, optical data storage, autonomous data system control, and data compression. The rover and lander power functions require developments in energy sources and the conversion, storage, and light weight distribution OF power. Rover thermal control will require developments in materials and subsystems. Depending upon when the

function could be met by either Ka band o r optical communications technology.

--, MRSR mission is initiated, the communications

Aerobraking is required for all of the mission options currently under study by OSSA, either at Mars, for Earth return, or both. Use of aerobraking will require code development, an understanding of chemistry effects, and developments in navigation capabilities and thermal protection systems. weight for the mission could be increased by developments in parachute technology, including supersonic deployment and reefing, materials, and stability and maneuverability. Wind tunnel and flight experiments would be required for these developments. avoidance function, technology developments including algorithm development, sensor developments, and a flight experiment w i l l be required. To avoid the 100% mass penalty associated with direct return OF Martian samples to Earth, the Mars orbit rendezvous and docking function requires development in sensing systems and trajectory control, and will require a Flight experiment.

Many of these technology requirements are addressed by OAST technology programs including CSTI and Pathfinder. CSTI includes program elements in automation and robotics; sensors; on- board data processing and storage; and aerobraking. Pathfinder will develop technology options for potential Agency bold new initiatives including the Robotic Exploration and Humans to Mars initiatives, and includes program elements in planetary rovers; surface power; optical communications; sample acquisition, analysis and preservation; autonomous rendezvous and docking; in-space assembly and construction; fault-tolerant systems; autonomous lander; and high energy (planetary return) aerobraking.

The effective payload

To support the landing hazard

ADVANCED OBSERVATORIES

The use of interferometric methods and partially Filled apertures For advanced astrophysics observatories promise at least an order of magnitude increase in resolution over the Hubble Space Telescope, and over two orders on magnitude increase over ground-based resolution. In cooperation with the OSSA Astrophysics Division, OAST has been studying the technology requirements for advanced space-based optical interferometers (Figure 6). The study approach is to identify and lay out possible subsystem technology alternative8 for candidate conFigurations, and to quantitatively assess the optics, structures, and controls technology options. Preliminary struchural simulation results indicate a potential For reasonable deployable conFigurations with good static, dynamic, and thermal behavior. However, more extensive simulations and testing of structures and materials to the sub-micron level will be required. Study of overall control technology alternatives is continuing.

Major technology developments in optics and related areas will be required to support the reconstruction OF images. Interferometric techniques require the coherent combining of the light received From distributed telescopes, and this requires the control of the optical path length to a fraction of e wavelength of light ( 0.01 micron) over integration times as long a9 2,000 seconds (33 minutes), For all OF the dozens

4

of telescopes in the system. Configurations to accomplish this have relied upon multiple mirrors

technology advances to improve performance at ultra-violet wavelengths.

Major problems have been found with the pupil beam combinations approach to coherently recombining the received light, and current efforts have focused on the phased im?ging approach. efforts to develop a laser metrology path- compensation system indicate that a major design and development effort will be required. Optics technology advances are required to increase optical system performance for the individual telescopes that make up the distributed aperture. To better understand the sensitivity and potential for improving optical performance, development of image simulation software is required.

- OP optical fibers, both of which require

Study

ADVANCED SPACECRAFT TECHNOLOGIES

In order to identify the technologies required to build spacecraft of the 21st century Spacecraft 2000 workshop was held in July, 1986*,'. Spacecraft 2000 is a program whose purpose is to work with spacecraft manufacturers to identify critical high payoff spacecraft technologies. primary characteristics that spacecraft of the 21st century are expected to possess are modular standard interfaces, autonomous operation, and repairable, serviceable subsystems. Four basic critical issues were identified for the

u workshop: spacewaft bus related costs; spacecraft bus subsystem weights; system lifetime and reliability; and reduction of technical risks for new technologies. accomplished by forming technology working groups in spacecraft systems, system development, structures and materials, thermal control, electrical power, telemetry, tracking and control, data management, propulsion, and attitude control. There was a clear consensus among the nine working groups that ground and space test beds are required to validate advanced systems and technologies.

A conceptyp study of a space-based test bed was conducted . The objective of the Space-based Test Bed (STB) is to provide this in-space testing capability; thus facilitating the introduction of new, advanced technology into spacecraft bus systems without increasing program risks. The conceptual design consisted of a 3-axis stabilized free-flyer with a nominal design life of five years, operating in a 400 km orbit. The basic STB is CQmposed of a main spacecraft bus with attachable/detachable experiment pallets. Individual experiment pallets (each with one or more experiments) are attached to the spacecraft bus and to other pallets by standardized, smart interfaces.

The

The workshop was

SUMMARY

New technology Will be required for future

security missions. The missions and systems -' spacecraft to perform both civil and national

platforms, planetary rovers and sample peturn vehicles, and advances interferometric astrophysics observatories. To provide the technologies required to support such diverse spacecraft in an affordable manner presents a genuine challenge.

Spacecraft will continue t o grow much more complex physically and functionally. advanced detectors and optical systems across the full range of the electromagnetic spectrum, and many will require improvements in precision pointing in order to optimize the output of the Sensors. Substantial augmentation to Jpacecraft communications, on-board processing, and data storage capabilities will be needed. Many spacecraft will have to have utilities that function autonomously. Systems analysis of spacecraft have indicated that potential advances in technologies such as those for spacecraft power and propulsion could double the spacecraft payload fraction by the mid 1990's. Such a gain could provide beneficial increases in science retwn and spacecraft profitability, and could be essential to the ability of the United States to remain competitive with the space programs of foreign countries.

Advance Geostationary Earth Science platforms could play a crucial role in addressing the challenge and uncertainty of global climate change, and lay the foundation for an operational Earth science system that would benefit all of the inhabitants of our planet. The Mars Rover and Sample Return mission could continue the adventure of exploring and understanding the nature of our solar system, and could lay the foundations for Human exploration and eventual habitation of Mars. interferometry technology could enable the next generation of great observatories beyond those currently planned by OSSA. These diverse missions form an exciting spectrum of opportunities for future spacecraft missions.

The will require

Advances in apace based optical

1.

REFERENCES

"Office of Space Science and Applications, Strategic Plan 1988, A Strategy for Leadership through Excellence in Space Science and Applications", Internal OSSA Document, April 1988.

2. S.K. Ride, "Leadership and Americas's Future in Spacen, A report to the (NASA) Administrator, August 1987.

3. Report of the Earth System Sciences Committee, NASA Advisory Council, "Earth System Science, A Closer View (A Program for Global Change)". January 1988.

4. Wayne R. Hudson, Eugene V. Pawlik, "Spacecraft Technology Requirements for Future NASA Missions". PaDer No. 1160-CD. AIAA Space Systems Technoiogy Conference, June 1986.

5 . NASA/OAST Summary Report, "Technology for the EOS Polar Orbitinn Mission. ADril 1986.

expecteh to be principle drivers of technology include advanced geostationary Earth science

-

5

6. “Mars Rover Sample Return (MRSR) Mission, Mars Rover Technology Workshop Proceedings,

v April 28-30, 1987, JPL E-4788.

7. “Summary Report, Technology for a Mars Sample Return (MSR) Mission”, NASAIOAST, July 1988.

8. “Spacecraft 2000, Proceedings of a Workshop held at NASA Lewis Research Center, July 29-31, 1986”, NASA.Conference Publication 2473, NASA Scientific and Technical Information Branch, 1987.

9. ‘Exeoutive Summary Report, Spacecraft 2000 Workshop”, General Research Corporation, January 1987.

“Conceptual Study of a Space-based Test Bed Concept”, C.L. Butner et al, General Research Corporation, February 1987.

10.

FIGURES

1 . Spacecraft Technology Mission Model

2 . Advanced Geostationary Earth Science Platforms

3. Earth System Processes: Characteristic Spatial and Temporal Scales

4. Geostationary Earth Science Platform MM-Wave Sounding: Footprint VS. Antenna Diameter

5 . Mars Rover and Sample Return

6. Optical Interferometry in Space

7 . Space-based Test Bed Conceptual Design

FIGURE 1

6

W

-4''

ADVANCED GEOSTATIONARY EARTH SCIENCE PLATFORMS

LARGE STABLE PLATFORMS AT GEO

SOUNDING ANTENNA

MULTIPLE INSTRUMENTS, PLATFORM AUTONOMY AND HIGH DATA RATES, ON-BOARD ROBOTICS

LARGE MM-WAVE ANTENNA BOTH INDEPENDENT AND SYNCHRONOUS POINTING

POINTING AND CONTROL OPERATIONAL SYSTEM: LONG LIFE, HIGHLY POWER AND PROPULSION

PLATFORM CHARGING RELIABLE 8 COST EFFECTIVE

ROBOTIC ALLY

LARGE (40 METER)'MM-WAVE DATA PROCESSING h STORAGE

E PLATFORMS FOR VATION OF THE EARTH

ABLE, COST EFFECTIVE NAL CAPABILITY

FIGURE 2

EARTH SYSTEM PROCESSES: CHARACTERISTIC SPATIAL AND TEMPORAL SCALES

I 1 I I I I I SCCOND MINUTE D b I *FAR CENTURV 1EN ONE cuf

TMOUSLND Ul lL lON BILLION *EAR6 *€ARB VLbRS

FIGURE 3

GEOSTATIONARY EARTH SCIENCE PLATFORM MM-WAVE SOUNDING

FOOTPRINT VS. ANTENNA DIAMETER 1 0 0

SO

1 0 - E 20

5 E 1 0

li

z 0

I S

a Y 3

2

1

10 GH.

- -. *. *.

-

- -

F - H x mn(i.2 I m) -

MTKUDE (HI - %,OM KY (SYNCHRONOUS ORBIT)

I I I I , *.

1 2 3 3 1 0 2 0 3 0 S O

ANTENNA DIAMETER (M)

FIGURE 4

MARS ROVER AND SAMPLE RETURN

I I MOBILE SURFACE ROVER

FLEXIBLE AND FAULT-TOLERANT OPERATIONS ROVER MOBILITY AND LOCAL NAVIGATION

COYPUlAnON AN0 DATA HANDLING WITH REDUCED GROUND RESPONSE TIME REOUIREYENTS

ROVER AND LANDER POWER AND M E R Y A L CONTROL

AUlONOYOUS AVOIDANCE OF HAZARDS (DURING LANDING AND ROVING)

ROVER AUTONOYV HIGH DATA CAPACITY AND RATES

COYYUNlCATlONS AEROBRAKING AT MARS AND EARTH

YARS ORBIT RENDEZVOUS. LANDING HAZARD AVOIDANCE DOCKING, AND SAYPLE TRANSFER

RENDEZVOUS AND DOCKING IN SITU IDENTIFICATIONI ANALYSIS OF SAMPLES FOR RETURN OPERATIOUS AUTONATION

- PRISTINE SAYPLE AEROBRAKING

PARACHUTE SVSTEYS PRESERVATION

FOR SCIENTIFIC AND A S A PREC

FIGURE 5

8

OPTICAL INTERFEROMETRY IN SPACE

1 HIGH RESOLUTION 0

LARGE PRECISION S

ADAPTIVE OPTICS PATH CONTROL OPTICAL FIBERS IN UV

DEPLOYABLE WAVELENGTHS

STABLE INTEGRATION FOR HIGH UV REFLECTANCE 2000 SECONDS MATERIALS

PATH LENGTH CHANGES LESS PRECISION DEPLOYMENT AND THAN 0.01 MICRON CONTROL OF STRUCTURES

EARLY 1990s SCIENCE1 TECHNOLOGY FLIGHT

DEMONSTRATION

ENABLE ORDER OF MAGNITUDE OR MORE INCREASE IN RESOLUTION OVER THE

HUBBLE SPACE TELESCOPE

FIGURE 6

SPACE-BASED TEST BED CONCEPTUAL DESIGN FIGURE 7

9