NASAReferencePublication1121

A_t 198.,Solar Absorptance andThermal Emittance of

Some Common Spacecraft

Thermal-Control Coatings

John H. Hemmer

(NASA-_-I 21) 50LAR &I_5OSP_ANCE ANL)

T_aaAL E._IT_AH(.E OF SC_E CC_MON Si)ACZCRA_T

_i!_L_AL-CGNTIIOL COATI_G5 (_ASA) _7 phC &OJ/M_" A01 CSCL 11D

N$_-23698

UncLas

UIIZq 19170

L

https://ntrs.nasa.gov/search.jsp?R=19840015630 2018-04-21T08:20:27+00:00Z

NASA

ReferencePublication1121

1984

Scientific and TechnicalInformation Branch

Solar Absorptance andThermal Emittance of

Some Common Spacecraft

Thermal-Control Coatings

John H. Henninger

_ddard 5,pace t"hgkt Center

(;r,',',tb, I',. .'_lar_land

MI measurement values are expressed in the International System of Units!3II in accordance with NASA Policy Directive "_n A....... paragraph 4.

ABSTRACT

Solar absorptance and thermal emittance of spacecraft materials are critical parameters in determin-

ing spacecraft temperature control. Because thickness, surface preparation, coatings formulation,

manufacturing techniques, etc. affect these parameters, it is usually necessary to measure the

absorptance and emittance of materials before they are used. Also, because most materials exhibit

some amount of degradation dye to outgassing, ultraviolet, and or particle damage, it is necessary to

conduct laboratory testing on these materials before certifying them for use in space.

This document contains absorptance and emittance data for many common types of thermal-control

coatings, together with some sample spectral data curves of absorptance, in cases for which ultra-

violet and particle radiation data are available, the degraded absorptance and emittance values arealso listed.

m

0°,111

w

CONTENTS

Page

...

..°.....°.°.°.o .... ° ...... ......°........ .... ....°....... m

' I:_IPflON OF MEASUREMENTS ......................................... 2

iNSTRUMENTATION ...................................................... 4

ULTRAVIOLET DEGRADATION TESTING COMMENTS .......................... 4

CONCLUSIONS ........................................................... 5

TABULATED DATA ....................................................... 7

REFERENCES ............................................................ 43

P_IN(; PAGE BI.ANg NOT gri'.ltfrD

Y

_ INTL_I_lOIIA,Id,Y

SOLAR ABSORPTANCE AND THERMAL EMITTANCE DATA OF SOME COMMON

SPACECRAFT THE RMAL-CONTROL COATINGS

John H. Henninger

Goddard Space Flight Center

Greenbelt, Maryland

INTRODUCTION

The Radiation Simulation and Thermal Control Section of the Environmental Test and Integration

Branch of the Goddard Space Flight Center (GSFC) routinely makes measurements on spacecraft

materials to determine their solar absorptance and thermal emittance (_ and e-n ) values for use inspacecraft thermal design. Except for calorimetric emittance, all measurements are made at room

temperature (300 K). It is normally assumed that samples are opaque (i.e., the thickness of the

coatings is sufficient to prevent interference from the substrate). Opacity is important because sur-

face preparation, coatings formulation, manufacturing techniques, thickness, and application pro-

cedu, es can greatly affect the absorptance and emittance.

The importance of the solar absorptance for spacecraft temperature arises from the fact that the

absorbed solar radiation is typically the predominant external heat input to the spacecraft. The im-

portance of the thermal emittance is that it controls the rate at which heat leaves the spacecraft. A

clearer idea of the effect of these parameters on spacecraft temperature can be obtained by con-

sidering the very simple case of a body in thermal equilibrium with solar radiation (i.e., there are no

other external heat sources and there is no source within the body). In addition, the body is iso-

thermal. For these conditions, the thermal equilibrium of the body implies that the solar radiation

absorbed equals the long-wave radiation emitted (reference 1 ). This is expressed as:

A_ sa = Ao eT4

or solving for T gives:

where

o

¼

T = temperature

A s -- area perpendicular to solar radiation

A = total area emitting radiation

s = solar constant

a = absorptance

e = emittance

o = Boltzmann's constant

From these equations, it is evident that the selection of materials on the basis of their absorptance

and emittance values is of primary importance in spacecraft temperature control.

DESCRIPTION OF MEASUREMENTS

Solar Absorptance (_,) Measurement

To obtain solar absorptance of a material, reflectance as a function of wavelength is measured, from

which the absorptance is then calculated. The technique used at GSFC employs a spectrophotom-

eter with an integrating sphere attachment (reference 2) for collecting the reflected specular and

diffuse components of the material to obtain total reflectance versus wavelength valves. The reflec-

tance measurements are made over the portion of the electromagnetic spectrum from 0.3 to 2.4

micrometers because this region contains about 95 percent of the Sun's energy (reference 3).

Figures 1 through 20 show reflectance curves for some common materials.

Mathematically expressed, the procedure for computing the solar absorptance of a given material

from its total reflectance spectrum (specular and diffuse components) at a given angle of incidence,

0 (reference 4), is:

_(0) = 1-_(0)

b'(0) =

f _, = 2.4/_m R_, (0) H ), d ),= 0.3/_mm i ii i

f_'_ H ), d2 Q4 9m

= 0,3 _m

where

• (0) =

RX(O) =

H)_ =

_(0) =

solar absorptance at angle of incidence 0

total reflectance at wavelength _, at 0

solar extraterrestial spectrum

solar reflectance at 0

In practice, the integrals are approximated by discrete summations (numerical integration).

-)

At GSFC, manual data reduction for absorptance has been replaced by using encoders attached to

the pen and wavelength drives of the DK-2 spectrophotometer. Data from the encoders are trans-

ferred to a microcomputer through an appropriate interface. A 'basic' computer program is used to

process the encoded data and automatically calculate the absorptance of the material.

Normal Emittance (e'n)

In the past at GSFC, room-temperature emittance measurements (300 K) were made using an

infrared spectrophotometer with an attached heated cavity (Holhraum), (reference 5). This infrared

source was used both as a reference and for illuminating the sample. Spectral reflectance measure-

ments were made over the wavelength region from 5 to 35 micrometers. This region contains

approximately 90 percent of the energy of a 300 K blackbody radiator (reference 1). These data

were used to calculate the emittance. This type of instrumentation was difficult to maintain and

ha_ been replaced at GSFC with the much simpler portable emissometer manufactured by the Gier-

Dunkle Instrument Company, a subsidiary of Dynatech, Incorporated.* The DB-100 portable

emissometer gives an integrated value of normal emittance with a high degree of accuracy for most

nov,selective or gray materials. For selective materials (reference 6), the errors can be significant,

but these errors can be minimized by the experienced operator if correction factors are known or

can be determined. Normal emittance measurements fin ) are converted to hemispherical emittance

(e'h) by using conversion factors determined by Jakob (reference 7).

The following formulas are used for computing total normal emittance, _. (reference 4):

_'. (T) = _n(T)

_.(T) = l-_.(T)

_ = 35 pm: 5 pm p.(k) J)_(T_I?,.

_,(T) f_, : 35 pm D,(T) d),J_,: 5 pm

J),(T) = Planckian blackbody function

g. (T) = Total normal emittance at T

_n (T) = Total normal absorptance at T

_. (T) = Total normal reflectance at T

in actual computations, discrete summations are used in place of the foregoing integrals.

Calorimetric Emittance

A_,other method of making emittance measurements, developed and in use at GSFC. employs a

calorimetric technique to determine emittance. This method is known as a transient thermal

*Gier.Dunkk,Incorporated,SantaMonk:*,California.

o,

technique for obtaining emittance. A complete description of the calorimetric facility and measure-

ment technique is given in reference 4.

INSTRUMENTATION

Many different type spectrophotometers are available for use in making absorptance and emittance

measurements. The systems at GSFC have been in use since 1965. Some modifications have been

made in recent years, mainly in the areas of computerized data reduction and integrating sphere-

coating improvements. The sodium ctdoride (NaCI) and barium sulfate (BaSO 4 ) coatings used today

have proved to be much more durable than the old 'smoked' magnesium oxide (MgO) coatings.

Solar Absorptanca (_)

A Beckman DK-2A spectrophotometer modified with a Gier-Dunkle absolute integrating sphere

(Figure 21 ) is used for making absolute reflectance, absorptance, and transmittance measurements.

This instrument covers the wavelength region from 300 to 2400 nanometers (nm). The ir_trument

is coupled to a microcomputer for data reduction. The manufacturer's data lists an accuracy of

-+0.015 u,its over the total measurement range.

Normal Emittance (_".)

The Gier-Dunkle portable emissometer, model DB-100 (Figure 22) is used to make normal emittance

measurements at room temperature. This instrument gives a single integrated value of emittance. It

uses dual rotating cavities that reference sample radiation against an essentially room-temperature

blackbody. The instrument has a potassium bromide (KBr) thermocouple detector, which is sensi-

tive over the 5- to 25-micrometer wavelength range. The manufacturer's data lists an accuracy of

en +0.02 units over the total measurement range for nonselective materials and Vn +0.04 for mostselective materials.

Hemispherical Emittanca (e'h)

The hemispherical emittance system is composed of a high-vacuum chamber with a liquid nitrogen

(LN 2 ) cooled shroud (Figure 23). The inside of the shroud is painted with a highly absorbing blackpaint. Vacuum pressure is maintained at I 0"6 tort, whereas the shroud is kept at liquid nitrogen

temperature. Samples are suspended within the shroud _nd are heated through a 5-inch diameter

quartz port using an X25 solar simulator.* Calorimetric emittance measurements can be made over

a temperature range of +70 ° to -70°C using this system. A larger temperature range can be obtained

for some types of materials. Data reduction for emittance is accomplished with the aid of a micro-

computer using the temperature versus time data.

ULTRAVIOLET D[ "RAOATION TESTING

Because many materials .sed for thermal-control purposes exhibit degradation when exposed to

ultraviolet (UV) or particle radiation, efforts to simulate this degradation have been carried out on

*Manufactured by Spectrolab, Incorporatod, Los Angeles, CaIlfornb.

4

__.._

many types of coatings. The object of the degradation testing has been to determine if the materials

to be used will survive their planned missions without exceeding a predetermined degradation value.

A complete list and description of degradation testing facilities at GSFC has been published (refer-

ence 8). This list includes a solar-wind facility (Figure 24) (UV and protons), vudarms system (UV

and reflectance), and multisedes system (Figure 25) (multisample UV and reflectance).

The X-25 solar simulator is the source used for ultraviolet degradation because it gives a very good

match with the solar spectrum. Since certain materials are subject to partial recovery from degrada-

tion effects (UV and particles) when re-exposed to the atmosphere, it is often necessary to make

measurements in situ to determine accurate changes in absorptance values.

CONCLUSIONS

Because a continual need exists for measurements in thermal-control analysis, absorptance and emit-

tance measurements will continue to be made on old and new materials. With future Shuttle flights,

and gn values will be necessary in support of instrumentation and as a check for contaminationof various flight surfaces. Absorptance and emittance values are not the sole criteria for selecting

coatings because selection usually represents a compromise of many factors. Coatings stability in

space, mission life, orbit factors, instrument functions, and coatings outgassing properties are some

of the more important criteria in selecting a coating for flight use.

This document lists only the more commonly used and requested data. The values are average ones

that generally reflect a tolerance on absorptance and emittance of +0.02 units over the total mea-

surement range (e.g., (_ or in - 0.XX +-0.02)). Because, as previously mentioned, many factors caninfluence absorptance and emittance values, it is suggested that confirmation measurements should

be made on specific sample materials before final commitment to spaceflight use.

Goddatd Space Flight Center

National Aeronautics and Space AdministrationGreenbelt, Maryland December 1983

BLACK COATINGS

en

Anodize Alack " 0.88"

Carbon Black Paint NS-7

Catalac Black Paint

Chemglaze Black Paint Z306

Delrin Black Plastic

Ebanol C Black

Ebanol C Black-384 ESH* UV

GSFC Black Silicate MS-94

GSFC Black Paint 313-1

Hughson Black Paint H322

Hughson Black Paint L-300

Martin Black Paint N-150-1

0.88

0.96

0.96

0.96

0.96

0.97

0.97

0.96

0.96

0.96

0.95

0.94

Martin Black Velvet Paint

3M Black Velvet Paint

Paladin Black Lacquer

Parsons Black Paint

0.91

0.97

0.95

0.98

Polyethylene Black Plastic

Pyramil Black on Beryllium Copper

Tedlar Black Plastic

Velestat Black Plastic• =

0.93

0.92

0.94

0.96i

*ESH = equivalent Sun hours of ultraviolet radiation.

0.88

0.88

0.91

0.87

0.73

0.75

0.89

0.86

0.86

0.84

0.94

0.94

0.91

0.75

0.91

0.92

0.72

0.90

0.85

. ::_,i';': FA::I: BLANK N_T FILMED

toat 'aon, tv

WHITE COATINGS

i ,

Barium Sulphate with Polyvinyl Alcohol

Biphenyl-White Solid

Catalac White Paint

Dupont Lucite Acrylic Lacquer

Dow Coming White Paint DC-O07

0.06

0.23

0.24

0.35

0.19

GSFC White Paint NS43-C

GSFC White Paint NS44-B

GSFC White Paint MS-74

GSFC White Paint NS-37

Hughson White Paint A-276

0.20

0.34

0.17

0.36

0.26

Hughson White Paint A-276 + 1036 ESH UV

Hughson White Paint V-200

Hughson white Paint Z-202

Hughson White Paint Z-202 + lO00 ESH UV

Hughson White Paint Z-255

Mautz White House Paint

3M-401 White Paint

Magnesium Oxide White Paint

Magnesium Oxide Aluminium Oxide Paint

Opal Glass

OSO-H _Vhite Paint 63W

P764-I A White Paint

Potassium Fluorotitanate White Paint

Sherwin Williams White Paint (A8Wl l )

Sherwin Williams White Paint (F8W2030)

Sherwin Williams F8W2030 with Polasol

V6V241

Sperex White Paint

Tedlar White Plastic

Titanium Oxide White Paint with Methyl

Silicone

Titanium Oxide White Paint with Potassium

Silicate

Zerlauts S-l 3G White Paint

Zerlauts Z-93 White Paint

Zinc Orthotitanate with Potassium Silicate

Zinc Oxide with Sodium Silicate

Zirconium Oxide with 650 Glass Resin

0.44

0.26

0.25

0.40

0.25

0.30

0.25

0.09

0.09

0.28

0.27

0.23

0.15

0.28

0.39

0.36

0.34

0.39

0.20

0.17

0.20

0.17

0.13

0.15

0.23

0.88

0.86

0.90

0.90

0.88

0.92

0.91

0.92

0.91

0.88

0.88

0.89

0.87

0.87

0.89

0.90

0.91

0.90

0.92

0.87

0.83

0.92

0.88

0.87

0.82

0.87

0.85

0.87

0.90

0.92

0.90

0.92

0.92

0.92

0.88. .

8

®

CONDUCTIVE PAINTS

Brilliant Aluminum Paint

Epoxy Aluminum Paint

Finch Aluminum Paint 643-1-1

Leafing Aluminum in Epon 828

Leafing Aluminum (80-U)

NRL Leafing Aluminum Paint

NRL Leafing Aluminum Paint

Silicone Aluminum Paint

Dupont Silver Paint 4817

Chromeric Silver Paint 586

GSFC Yellow NS-43-G

GSFC Green NS-53-B

0.30

0.77

0.22

0.37

0.29

0.24

0.28

0.29

0.43

0.30

0.38

0.52

GSFC Green NS-43-E

GSFC White NS-43-C

GSFC Green NS-55-F

GSFC Green NS-79

0.57

0.20

0.57

0.57

0.31

0.81

0.23

0.36

0.32

0.24

0.29

0.30

0.49

0.30

0.90

0.87

0.89

0.92

0.91

0.91

i

- °

9

ANODIZEDALUMINUM SAMPLES*

S

Black

Black

Blue

Blue

Brown

Chromic

Clear

Clear

Green

Gold

Plain

Red

Sulphuric

Yellow

Blue Anodized Titanium Foil

m ,.

0.65

0.86

0.67

0.53

0.73

0.44

0.27

0.35

0.66

0.48

0.82

0.86

0.87

0.82

0.86

0.56

0.76

0.84

0.88

0.82

0.26

0.57

0.42

0.47

0.70

0.04

0.$8

0.87

0.87

0.13

*Coating thickness is critical.

10

®

METALS AND CONVERSION*

Alzac A-2

Alzac A-5

Black Chrome

Black Copper

Black lrridite

Black Nickel

Buffed Aluminum

Buffed Copper

Com,antan- Metal Strip

Copper Foil Tape

Plain

Sanded

Tarnished

Dow 7 on Polished Magnesium

Dow 7 on Sanded Magnesium

Dow 9 on Magnesium

Dow 23 on Magnesium

Ebanol C Black

Eiectroplated Gold

Electroless Nickel

lrridite Aluminum

inconel X Foil (1 rail)

Kannigen - Nickel Alloy

Plain Ber/llium Copper

Platinum Foil

Stain1 _'ss Steel

Polished

Machined

Sandblasted

Machine Rolled

Boom-Polished

i-rail 304 Foil

Tantalum Foil

Tungsten Polished

COATINGS

_$

0.16

0.18

0.96

0.98

0.62

0.91

0.16

0.30

0.37

0.32

0.26

0.55

..

.°

.°

0.62

0.97

0.23

0.39

..

0.52

0.45

0.31

0.33

0.42

0.47

0.58

0.39

0.44

0.40

0.40

0.44

_r

0.73

0.62

0.63

0.17

0.66

0.03

0.03

0.09

0.02

0.04

0.04

0.49

0.65

0.87

0.67

0.77

0.03

0.07

0.11

0.10

0.08

0.03

0.04

0.11

0.14

0.38

0.11

0.10

0.05

0.05

0.03

*Thickness of coating can change values significantly.

II

VAPOR-DEPOSITED COATINGS*

_s _n

Aluminum

Aluminum on Fiberglass

Aluminum on Stainless Steel

Chromium

Chromium on 5-mil Kapton

0.08

0.15

0.08

0.56

0.57

Germanium

Gold

Iron Oxide

Molybdenum

Nickel

Rhodium

Silver

Titanium

Tungsten

0.52

0.19

0.85

0.56

0.38

0.18

0.04

0.52

0.60

*On glass substrates except as noted.

0.02

0.07

0.02

0.17

0.24

0.09

0.02

0.56

0.21

0.04

0.03

0.02

0.12

0.27

12

° h° dPq 8.° -- n mUll

®"-1

SOLAR CELLS

Spacecraft &s _'.

AE

AMSAT

ATN Black

ATN Blue

ATS-F

COMSAT

DE

ETS/GOES

GOES

GPS-Conductive Coating

HELLOS

IME-Conductive Coating

IMP-H

IMP-I

ISEE-Conductive Coating

IUE

OAO

PAC

SMS-B

Spanish INTASAT

SSS

0.78

0.82

0.77

0.86

0.85

0.82

0.77

0.82

0.91

0.81

0.80

0.75

0.78

0.78

0.91

0.86

0.85

0.77

0.81

0.86

0.79

0.82

0.85

0.80

0.85

0.85

0.85

0.81

O.8O

0.81

0.80

0.82

0.79

0.82

0.81

0.79

0.84

0.81

0.81

0.80

0.86

0.82

13

COMPOSITE COATINGS

Aluminum Oxide (AI 203 )-(! 2 X/4) on Buffed Aluminum

Initial

2560 ESH UV + P*

Aluminum Oxide (AI 2 03 )-(! 2 ),/4) on Fused Silica

0.13

0.13

0.12

Silver Beryllium Copper (AgBeCu)

Kapton Overcoating

Parylene C Overcoating

Teflon Overcoating

GSFC Dark Mirror Coating-SiO-Cr-Al

GSFC Composite SiOx-Al 2 03 -Ag

Helios Second Surface Mirror/Silver Backing:

Initial

24 Hours at 5 Suns

48 Hours at I l Suns + P+

lnconel with Teflon Overcoating-I rail

Vespel Polyimide SP!

0.19

0.31

0.22

0.12

0.86

0.07

0.07

0.07

0.08

0.55

0.89

0.23

0.23

0.24

0.03

0.57

0.34

0.38

0.04

0.68

0.79

0.80

0.79

0.46

0.90

I4

FILMSANDTAPES

m, i i i ,

Aclar Film (Aluminum Backing)

1 mil

2mil

5mil

Kapton Film (Aluminum Backing)

0.08 rail

0.15 rail

0.25 rail

0.50 rail

].0 mil

1.5 mil

2.0 rail

3.0 rail

5.0 rail

Kapton Film (Chromium-Silicon Oxide-Aluminum Backing

(Green))

!.0 rail

Kapton Film (Aluminum-Aluminum Oxide Overcoating)-! rail

Initial

i 800 ESH UV

Kapton Film (Aluminum-Silicon Oxide Overcoating)- ! rail

Initial

2400 ESH UV

Kapton Film (Silver-Aluminum Oxide Overcoating)- 1 rail

Initial

2400 ESH UV

Kapton Film (Aluminum-Silicon Oxide Overcoating)-0.5 mil

Initial

4000 ESH UV

Kimfoil-Polycarbonate Film (Aluminum Backing)

0.08 rail

0.20 rail

0.24 rail

0.12

0.11

0.11

0.23

0.25

0.31 !0.34

0.38

0.40

0.41

0.45

0.46

0.79

0.12

O.12

O.ll

0.22

0.08

0.08

0.12

0.28

0.19

0.20

0.17

0.45

0.62

0.73

0.24

0.34

0.45

0.55

0.67

0.71

0.75

0.82

0.86

0.78

0.20

0.20

0.33

0.33

0.19

0.21

0.18

0.24

0.23

0.30

0.28

15

16

FILMS AND TAPES (Continued)

Mylar Film

Aluminum Backing

0.15 rail

0.25 mil3.0 rail

5.0 rail

Skylab Sail

Initial

1900 ESH UV

Skylab Parasol Fabric (Orange)

Initial

2400 ESH UV

Tedlar (Gold Backing)

0.14

0.150.17

0.19

0.15

0.19

0.51

0.65

0.5 rail

1.0 rail

Teflon

Aluminum Backing

2 mil

5 rail

!0 rail

Gold Backing

0.5 rail

!.0 mil

5 mil

IO rail

Silver Backing

2 rail5 rail

I0 rail

Tefzel (Gold Backing)

0.05 mil1.0 mil

Tapes

235-3M Black

0.30

0.26

0.08

0.130.13

0.24

0.22

0.22

0.23

0.08

0.08

0.09

0.29

0.26

0,95

425-3M Aluminum Foil

850-3M Mylar-Aluminum Backing

7361 - MysticAluminized Kapton

7452- MysticAluminum Foil

7800- MysticAluminum Foil

Y9360- 3M Aluminized Mylar

0.20

015

c_.09

0.140.21

0.19

0.28

0.340.76

0.77

0.35

0.36

0.86

0.86

0.49

0.58

0.66

O.810.87

0.43

0.52

0.81

0.82

0.680.810.88

0.47

0.61

0.90

0.03

0.59

0.03

0.03

0.03

0.03

®

ORIq_INAL PAGE II

OF POOR QUALITY

............ ° ....................... , .....

!

I

!

!

|

t.0

v

°-

Z

I,L

17

I%) _13N¥ J._'3"l:ll_tl

I]

__r...i...........................

.._,...._....................3"

!

:L!_ ,............ !....... !..........• i i .

i

!1

l

I

I!

I

!!

II

&iZ

Ill

8 •

ORIGINAL PA(_" _1OF POOR QUAL/TY'

g i i_ . ,,, D F m m ._ I!

i I ' "" i

I

I

II!

I

l

I,,-

Ee-'

o_

E

<l,OC,,,I,y

@

Ee-

E

@

e,i

&

i9

ORIGINAL PAGE Ig

OF POOR QUALITY

!i

!!

!

!

!

!

!

|

2O

e-ra

C

T

._gu.

ORIEL PAG£ I,_

OF POOR QUALITY

¢-

t-

-g

IJ

21

OF POOP,Q_ AL..rt'Y.

{,_ I_NVJ.O_2"I:I| ¥

22

. .

. •

I'-"

_i

G°_rF/C-'_AI..PAG[;9POOR QUALFI_f

(%) 3_NY/_31d3U

1 I

: • !

I i " I ' ! " ' " T

T '_ _T........ rh-_-- t........ . ........*.... _........ =........:...............

....-_--'_-....-_'--IL: .......I ...... _....r....' ; .........

-Q-+............. -_............+----_ - i -

:_,_-i+LI!_.....f......I........_........!:_::i:: : : :....iLilsLLIi_ssLLr:...!111.....i.i]

. . : , . .

! I

t , r ' ; I

...._ .......i....... i....... _...... ] ---; ............. _...........

] •

!

!

!

lI

I

m

!

il

II! ..... i..............? . _ -l-----T_'-r----I-......T.........i...............................+ " : ........... lit"

.................... |', i:_;..... ; ...... ! 't_....... : ....................:'"t *'_ __ _ ' _ ' i ....

I- I........÷.........__i ....1............i ! _ , : Ill

]........I-:.......ali..............i.........!,.i , : :.:: :i':: . I !.....i......:......: .............. I,

" I ......

............. i................ . ....

.... ! ' i "

_-i:_......................

I,

,

I

!

I

!

l

1

+I

ORIGINAL PAGE 18

OF POOR QUALITY

|

|

!

|

O.w

I

c_

oo

U.

•" 24

ORIGINAL PAGE !_OF POOR QUALITY

CD

0

Z

CD

o

UJ

oo

C0

A

I,.=

Eot-O

rn

0

r'C_e,.

.__

2_

z

" i _ 1 . i ....

...... _ ....... L . . ,

............................ I.i

I

.... i.

" " : • • " l

!........... t

m

ii'"'hi°! • t i' _ ................ i ...... J,.............. _ .........

_... i ! : _ i

U:I i

i.... i..._ . , . _ ......

' ' i i i * '• _ . _ .. , ..... . . .

!

.I.

• ' _ * P m

.. '_ . i , . '

!

M.

. ORIGINAL PAGE ISOF POOR QUALITY-- (%) 3:)N¥133"l:I3U

; ! ! I !

__ I I I j I

|

: 8

m

.!1

M

.L : • ;-i ..... i i " .....'---!-,-_ .........i----,----i------!....... _.........i.........i........ : . ,E h

'* ; r I l I ;

......... _ ........ -1 ........ _----,----1 ...... i ...... i. _ i-

I i ! ! I -:-"T"• ' .... _.....i........ *......i......._ i........i i i-

..I.. ' ................... ' ' ............ ; ............

1 ' t ....... • !

_-..... l..... ; .... L...... 2

........................... l..... a .......i .......... ; ........

i ' i :

......... f ......... f ......... it........ ! ...... ,

....i....... 1.......... i ..... , ....! ! ' i ! i , ,

: : .-. .

!

I

I

I

!

l

il

P

II

ill

!

I

l

1.

il'

il_

:t

o

¢0Q,.

,21

e,,,i(I}

f,,}

"0

0

ulLUCar}i

=1

ii

27

-'% ,e.(I _ _..",,_, dl_

ORiGIINAI..PAGE UOF POOR QUALITY

(%1_IONV.I,._"I:I _iU

m'

I

D

!

...... _...... i .... _ ....... . ..... _........ ,....... _.....

i

!

II

II

!1

I

l

I

I

!1

!

III

28

ORIGINAL PAGE nil

OF POOR QU,'i.ITY.

29

.,- .._ • -7--...,_;7__ __---'-..., - ...... "

ORIGINAL PAGE IS

OF POOR QUALITY

I

3O

ORI(_III',I,RL FP,_ _1

OF POOr QU:Vn'_.

|_t,)331_lVL3:l"t:lDU

i " _ i " ! " I : _ " : t ' : " • ' , i i ' ' ': i / ! i I l I / _ ! I ;

..... i.... :._ : ._ I . J _.. t .1 : .....LI : i. 1 . , . _ - -/ ; / i i " " I _ t _ !

_.: t ! r: I I.L! ! : I i / ! /; i [_t : I i t----t----7_ I _ I

_--i--r -r- -7.... :---r- -:.... . .... ',- T- -"..... __' :-.... :t .... _ t i jII_I

'-+ ..... " --_ ......._-.... _.......... _.... _-..... _.... "-- '÷ .... _.... _- _ ........ ! " i " i .,t,t t+tt: ,t,t,t t,f i -i r 7 t _ T ' ': i i i _ { -_--T--_-,_....t 7-it:_--__--t-_-ti-t:t:-:_-c-t--tt-_:t--:-t-r--}_:L-_ ........i " i !. _ <_I

....... [ _ I_ } _ I:lllP ....... kli_--l[ _:, t t t, t, r,-t,f f ! , t.... I .... _ ...... "-- -- ! + .... _----'----" "" " t " "' t • . iiG_,,,,___i !1 r i ' }_ I: l':17 lil 1 i/ r I 1 I ! I _-!+_-r - "- -i ..... :........+...... r.... -' 'T ...... i-..... :,.... i- " "-.... ' ..... ! .... t f i

"" _ t _ 1 ' ,l - i ' - _ " _ l .... ,l _ _,.

_ ] l/ i : i I i i 1 : 1 : _ / _ 1 i ! " i _ ll"I>'-;-V[:::['I-t;I! r-iri ': r:!: t: :I: ! . . -t: i Ir_ _!tt_l_/; ' 7/'I-_I. ""--I t-f-T .......... i-

li_-!--; _ ! ; f "- --if----l---- - #---7"_ ...... _...... f .... _ " _ .......... 7---_-- : " t ' . 1 . t . 1- i : t • " i " ' ' ; ..

t

i.... r,--+'_.....","" _- ............

!1

I

I

II

IlL

P- _' h ., .., d --

31

-1

ORIr..-_AL PAGE ,'P

OF POOR QUALIT_

iI i .... ,........ N

!

!

32

i

[- .- i .... l •

3;t

____L_._LL_LL.

OF PO0_-, -_,,..:-_"'

!

c

8

°_

0

u

34

(*_ 3:)NVJ.:_]'I:i3 hi

• • 7

• • °

".l¢:

E

.<O)

C

.-I

c_qr.-.

Lo

LL.

35

®

ORIGINAL PAG 'e. [_.

OF POOR QUALITY

I

. . !!

I!

!

!

l

N

|

l

I

!

!

!

N

36

OmQINAL PAGE ill

OF POOR QUALITY

.>o_

(J

G)f.)t'-(u

.Qt_

O(n

:3

U.

37

38

!

ORIGINAL PAGE: IS

OF F'C,_)R QUALITY

k.

_D

E

E_D

_P

OOC_

(,¢

LL

F5

OF P:_"C/a _' __,:-'i'.'

Figure 23. Hemispherical emittance facility.

39

ORIGINAL Pf_,GE "a._

OF POOR QUALITY

/

"Ot"

._mU.

4O

ORIGINAL PAGE IS

OF POOR QUALITY

• o

41

.

.

REFERENCES

Schach, Milton, and Robert E. KidweU, Jr., Thermodynamics of Space Hight (Heat Transfer

Phenomena in Space) NASA TM X-51282, March 25, 1963.

Edwards, D. K., J. T. Gier, K. E. Nelson, and R. D. Roddick, "Integrating Sphere for Imperfectly

Diffuse Samples," Applied Optics, 51, November 1961.

3. Johnson, F. S., "'The Solar Constant," J. of Meteorology, I 1, 1954.

. Fussell, W. B., J. J. Triolo, and J. H. Henninger, "A Dynamic Thermal Vacuum Technique for

Measuring the Solar Absorptance and Thermal Emittan_ of Spacecraft Coatings," GSFC

TN D-1716, March 1963.

. Dunkle, R. V., D. K. Edwards, J. T. Gier, K. E. Nelson, and R. D. Roddick, "Heated Cavity

Reflectometer for Angular Reflectance Measurements," Prog. in International Research on

Thermo and Transport Properties, ASME, 1962.

6. Heaney, James B., and John H. Henninger, "A Method of Treating the Non-Grey Error in

Total Emittance Measurements," GSFC TN D-6501, December 1971.

7. Jakob, M., Heat Transfer, Vol. !, John Wiley Company, New York, 1962.

8. Engineering Services Division Facility Handbook, Goddard Space Hight Center, January 1981.

"RECEDING PAGE BI, ANK NOT FILMED

43

®