UNCLASSIFIED

AD NUMBER

AD857658

NEW LIMITATION CHANGE

TOApproved for public release, distributionunlimited

FROMDistribution authorized to U.S. Gov't.agencies and their contractors; CriticalTechnology; APR 1969. Other requests shallbe referred to Air Force Rocket PropulsionLaboratory, ATTN: RPOR/STINFO, EdwardsAFB, CA 93523.

AUTHORITY

AFRPL ltr dtd 20 Mar 1974

THIS PAGE IS UNCLASSIFIED

AFRPL-TR-69-12

MONOPROPELLANT EXHAUSTCONTAMINATION INVESTIGATION

P.J .MA RTIN KO VIC

_TECHNICAL REPORT AFRPL-TR-69-12

4~~I APRIL 1969 S P 6

THIS DOCUMENT IS SUBJECT TO SPECIAL EXPORT CONTROLS AND EACH TRANSMITTALTO FOREIGN GOVERNMENTS OR FOREIGN NATIONALS MAY BE MADE ONLY WITH PRIORAPPROVAL OF AFRPL (RPOR/STINFO) EDWARDS, CALIFORNIA 93523.

F

AIR FORCE ROCKET PROPULSION LABORATORYL DIRECTORATE OF LABORATORIES

AIR FORCE SYSTEMS COMMAND

MACY--UNITED STATES AIR FORCEs~wUWARDS, CALIFORNIA _

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NOTICES /

When U.S. Government drawings, specifications, or other data are usedfor any purpose other than a definitely related Government procurementoperation, the Government thereby incurs no responsibility nor any obliga-tion whatsoever, and the fact that the Government may have formulated,furnished, or in any way supplied the said drawings, specifications, orother data, is not to be regarded by implication or otherwise, as in any Imanner licensing the holder or any other person or corporation, or convey-ing any rights or permission to manufacture, use, or sell any patented

invention that may in any way be related thereto.I

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AFRPL-TrR-69-72

MONOPROPELLANT EXHAUST CONTAMINATION INVESTIGATION

P. J. Martinkovic

This document is subject to special export controls and each transmittal to0 foreign governments or foreign nationals may be made only with prior ap-

proval of AFRPL (RPORISTINFO), Edw.ards, California 93523.

rI

IFOREWORD

This report surnmarizes work performed during a USAF in-house pro-grane under Project 624AOODRV, during the period November 1967 throughNovember 1968.

The program was ccnducted by the Liquid Rocket Division of the AirForce Rocket Propulsion Laboratory (AFRPL) at Test Stand 1-15, SpaceChamber Number 4. Mr. Paul S. Martinkovic was the project engineer.

The author gratefully the assistance of the following in-dividuals and organizations in suppnrt of thi. program: Mr. R. Fern andMr. K. Johnson of the Martin Marietta Corporation, Denver, Colorado,for providing and applying the Transtage th-r.nal paint to AFRPL-furnishedcoupons and also conducting the pretest and posttest measurements of thetest specimens; Mr. L. D. Massie of the Aero Propulsion Laboratory,Wright-Patterson AFB, Ohio, whose organizatirn provided the solar cellsand also conducted the pretest and posttest mLasurements of the cells;

Mr. R. Winn of the Materials Laboratory, Wright-Patterson AFB, Ohio,whose organization conducted the pretest and posttest measurements of theoptical coupons; Mr. R. L. Kline and Mr. V. DeMattia of Hamilton Standard,a division of United Aircraft Corporation, Windsor Locks, Connecticut, whoprovided the plume source engine as well as engine operational data.

This report has been reviewed and approved.

E.E. STEINChief, Propulsion Subsystems BranchLiquid Rocket DivisionAir Force Rocket Propulsion Laboratory

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I ABSTRACT

This report presents the results of the Monopropellant Attitude-ControlRocket (ACR) Exhaust Contamination Investigation. The purpose of thiseffort was to determine ACR engine plume effects on vehicle space -borneequipment, i. e., thermal control paint, solar cells and optics. Plumekit:5Vimpingement tests were conducted at an altitude of 400, 000 feet using ant2 5-lb-thrust, monopropellant, attitude-control rocket engine. The pro-pellant was hydrazine (N 2 H4 ) and the ignition source was Shell 405 catalyst.A series of 200 firings were conducted at each test position at an enginepulse width of 200 milliseconds. The analysis of the test data revealed_ that the mo:iopropellant ACR exhaust plume had little or no effect on theoperating characteristics of the space-borne equipment involved in the testprogram. .'urthermore, the monopropellant exhaust plume is very cleanfrom the contamination standpoint when compared to a bipropellant ACRplume using N 0 4 /A-50 and/or N 0 /MMH. This comparison is based onpast bipropellant plume contamination test results.

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TABLEOF COTENT4

Sectio -Pag3

I INTRODUCTION............... . .. .. .. .. ... 1tA

II OBJECTIVES.......................2

III APPROACH............................3

IV TEST FACILITY AND TEST SYSTEM............4

1. Altitude Chamber...................4

2. Plume Source AGR Engine ............... 4

3. ACR Engine Subsystem. ................ 5

V PHASE I TESTS -THERMAL-CONTROL COATINGS.61-

1. Test Configuration............ .. .. ... 6f

2. Test Position......................14

3. Test Conditions................... A14'4

4. es Results....................14

vi PHASE II TESTS - OPTICS AND SOLAR CELLS . . . . I8S

1. Test Configuration....................18

2. Test Position......................241

3. Test Conditions....................24

W 4. Test Result;.......................28

VII CONTAMINATION COUPON AND TEST RESULTS ... 49

VIII CONCLUSIONS.......................50

DISTRIBUTION...............................51

FORM 1473.............................

v

IIi ]FIGURES

Figure Page

I Schematic of Space Chamber No. 4 ......... .. 5

2 Space Chamber No. 4 ......... .......... 6

3 Vacuum Pumping System.......... .. .. .. .. .....

4 Monopropellant Attitude Control Rocket Engine,25-lb-Thrust ............ .......... 8

5 Schematic - ACR Engine Subsystem ............. 10

6 Phase I -- Test Configuration . .......... 127 Thermal-Control Coating Coupon ... ........ . 13

8 Phase I - Test Article Position .... ..... ... 15

9 Phase II - Test Configuration .... .. ... .. 19

10 Solar Cell Coupon ....... ........... 20

11 Solar Cell Installation ................ 21

12 Optical Coupon ......... ........... 22

13 Optical Coupon Installation ....... ........ 23

14 Phase II - Test Article Position .... .. ... . 25

15 Test Locations of Optical and Solar CellCoupons at the 5-Ft Test Position .......... 26

16 Test Locations of Optical and Solar CellCoupons at the 9-Ft Test Position . . ....... 27

17 Spectral Transmittance of Optical Coupon No. I . . .. 29

18 Spectral Transmittance of Optical Coupon No. 2 .... 30

19 Spectral Transmittance of Optical Coupon No. 3 ... 31

20 Spectral Transmittance of Optical Coupon No. 4 . . . 32

21 Spectral Transmittance of Optical Coupon No. 5 . .33

22 Spectral Transmittance of Optical Coupon No. 6 . . 34

23 Spectral Transmittance of Optical Coupon No. 7 .... 35

24 Spectral Transmittance of Optical Coupon No. 8 . . . . 36

25 Spectral Transmittance of Optical Coupon No. . 39

26 Spectral Transmittance of Optical Coupon No. 10 . . . 40

27 Spectral Transmittance o Optical Coupon No. 11 . . . 41

28 Spectral Transmittance of Optical Coupon No. 12 . . . 42

29 Spectral Transmittance of Optical Coupon No. 13 . . , 43vi

FIGURESFig9u reL

ge3 0 S e c t al T a n s i t t a c e f O p i c a C -, p o n N o .a g e-30 Spectral Transmittance of Optical G')upon No. 17 432 Spectral Transmittance of OpialCuo o. 17 . . . . 453 2 ~ T r a n s i t t a n c e o f O p t i c a l ( o u p o n N o 1 8 . .4

TAB LE'STable

PgI Pretest and Posttest Measurements of Thermal-.Control Coating Coupons..............

S17IL Comparison of Short- Circuit- Current Data on_Solar Cells Exposed at the 5-Foot Test Position . . . .* 38IIIComnparison of Short- Ci rcuit...Current Data onSolar Cells Exposed at the 9-Foot Test Position .. . . 46

vii/ viii 6

SECTION I

INTRODUCTION

The Space and Missile Systems Organization (SAMSO) requested the

Air Force Rocket Propulsion Laboratory (AFRFL) to investigate twoI Ipotential vehicle and propulsion integration problems associated with the

operation of the attitude-control engines on the Transtage vehicle. These

0problems were Attitude-Control Rocket (ACR) exhaust contamination of

(1) thermal control coating paint on the vehicle radiators and (Z) on-board

satellite equipment such as solar cells and optics.

Attitude-control rocket plume impingement on thermal paint can result

= in deposit ot contaminants and/or mechanical effects similar to sandblast-

ing which cou'.d severely degrade the ratio of solar absorptance and enit-

lk tance of the thermal paint. This condition can cause thermal problems Iwithin a vehicle compartment housing temperature-sensitive components.

Plume impingement on solar cells can result in severe damage to the°Icells, i. e., sandblasting of the reflective coatings and/or melting of the

solder connections due to high exhaust gas temperatures. Furthermore,

the operational characteristics of the cell can be affected by exhaust con- 1

taminant buildup. These conditions can severely deteriorate the power

o, tput of the solar panels.°I

ACR exhaust contamination of optics used for various functions (i. e. ,

telescopes, viewports, sensor windows and navigational equipment) can*create major problems. These problems are image distortion and deterior-

ation of optical transmittance.

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j SECTION II

I OBJECTIVES

£ The objectives of this program were to determine the severity of ACRI exniaust impingement effects on space-borne equipment. This was accom-

plished by (1) measuring any change in the initial ratio of absorptance andI ernittance of thermal control paint, (2) observing change in solar cell out-Iput and physical damage incurred, (3) observing image distortion and loss

jof transmittance through the optics as well as physical damage incurred,

and (4) attempting to identify the exhaust plume contaminants.

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SECTION III

APPROACH

i :The thermal control paint, solar cells and optics were subjected to

ACR plume impingement under vacuum conditions. During tests, in situ

measurement. were taken at various intervals to analyze contamination

trends for cox elation with posttest measurements. The test coupons were

maintained under vacuum conditions during the entire test phase, and upon

comletion of each test phase, the test specimens were removed from the

altitude chamber under a gaseous nitrogen atmosphere and placed into their

Irespective shipping containers. The test specimens were maintained in

this inert environment to minimize atmospheric contamination! during ship-

ment to the various laboratories for posttest measurements.

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SECTION IV

ITEST FACILITY AND TEST SYSTEM

1. ALTITUDE CHAMBER

I IThe test facility used for these tests was Space Chamber No. 4,

located in Test Area 1-15. The altitude chamber (reference Figures 1, 2,and 3) is 8 feet in diameter and 13 feet in length and incorporated a 5- by 5-

foot cryogenic (LN2 ) panel which served a twofold purpose: (1) cryopumpingI/to obtain the high start altitude and (2) the entrapment of exhaust particles

to minimize recirculation of the exhaust particles during an ACR firing.

IThe pumping system consisted of two 300-cfm mechanical pumps, a Roots

blower rated at 615 cfm and two 10-inch diffusion pumps, each rated at a

pumping capacity of 4200 liters per second. The pumping system incor-

porated three isolation valves to isolate the altitude chamber from the pump-

ing system. Such isolation (1) maintained a vacuum in the altitude chamber

during the evening hours and weekends without the pumping system on the

line to prevent atmospheric contamination of the test specimens during

extended test periods and (2) prevented ingestion of large quantities of

propellants by the pumping system in the event of a major failure of the

rocket engine and/or the ACR subsystem during tests. The test start

altitude and altitude degradation following each rocket engine firing was

measured by the use of a Pirani and ion vacuum gage and recorded on a

Leeds and Northrup Type "G" Recorder.IJ

j 2. PLUME SOURCE ACR ENGINE

The attitude-control rocket engine used for the contamination tests

was a Hamilton Standard monoporpellant rocket engine, reference Figure 4.

The ACR engine technical data are as follows:

Thrust 25 lb

Propellant 98% Hydrazine, 2% Water

Catalyst (two-stage) Shell 405

Weight 2. 70 lbs

Inlet Pressure 295 psia

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Nozzle Area Ratio 50/1Flow Rate .111 lb/sec

F 3. AGR ENGINE SUBSYSTEM

The ACR fluid system (reference Figure 5) consisted of two 3-liter

run tanks, associated valving and a GN, pressurization system. The pro-

pulsion subsystem incorporated a fuel dumping feature in order to remove

the hydra zine from the system in minimum time in the event of an emergency.j

The Hz0 scrubber system was designed to dilute the hydrazine to a safe

level of 60% water and 40% hydrazine. A 10-micron filter was installed

upstream of the rocket engine to prevent foreign material, if any, from

entering the redundant- series rocket engine propellant valves.

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. E PHASE I TESTS -THERMAL CONTROL COATINGS

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i The Phase I test hardware (reference Figure 6) consisted of a flat

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~surface panel, 36 by 44 inches, which incorporated seven flush-mounted

thermal-control coated coupons. The coupons were positioned downstream

1 .1

of the rocket nozzle exit within *he plume envelope of an ACR firing at

400, 000 feet as predicted by the Martin Marietta Company. Coupons 7 and

18 represented the lower area of the Transtage thermal radiator which is

~10. 5 inches from the centerline of the ACR roll engines. Coupons 2 through

| 6 were positioned closer to the ACR engine nozzle exit to obtain additional

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[ information for possible future reference. Coupons 1, 9 and 10 (which are

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~covered in detail in Paragraph 4, Test Results) were also involved in this

~~effort for control purposes. "

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The the rrmal -control coating was applied to a 3-inch-diameter aluminumSdisk which was epoxy-resin-bonded to a teflon flange (reference Figure 7. t

The purpose of the teflon flange was to minimize heat transfer between thecoupon pane by 4inel during takinooae situ measurements with

the xenon sun lamp. The test couppons were attached to the spacecraft panel

by the use of several wing nuts to facilitate removal of same under a gaseousnitrogen atmosphere, upon ompletion of tests, by a test crew member

wearing a Scott Air Pack breathing apparatus.

8 The instrumentation consisted of iron constantan (IC) thermocouples

attached to the underside of the coupons, and the test data were recorded on

a Leeds Northrup Type "G" recorder. Prior to the Phase I tests, baseline

measurements were taken of the coupons which consisted of measuring tem-

perature rise and temperature at equilibrium over a 75-minute period usingthe xenon lamp. Recordings were taken every 5 minutes during this time iperiod. During tests, temperature measurements were taken following 31,

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116 and 211 ACR firings at an engine pulse width of 200 milliseconds per

firing. The type of laboratory equipment used to obtain the pretest and?I

posttest measurements by the Martin Marietta Company were a Lion Re-

search Corporation emissometer Model 25B, and the R25C reflectometer.

The emissometer measures a s/E, the ratio of the solar absorptance to the

emittance in the 7 to 25 ; range. Solar absorptance, a s, was measured in,

the 0, '-5 to 2. 4 M range using the 7,25C reflectometer.

2. TEST POSITION

The Phase I test hardware (reference Figure 8) was positioned

paralled to the ACR plume and the distance from the centerline of the rocket

engine to the surface of the panel was 3. 5 inches. The xenon lamp and re-

flector were positioned directly above the test coupons. The reflector of

the lamp was protected from exhaust particles during an ACR firing by the

use of a solenoid-actuated protective shield.

3. TEST CONDITIONS

During the Phase I tests, the thermal-control coated coupons were

maintained under a continuous vacuum condition for a period of 432 hours

and were subjected to 211 ACR firings at an engine pulse width of 200 milli-

seconds. Start altitude for the ACR firing was 400, 000 feet and upon com-

pletion of a firing, the altitude decreased to 180, 000 feet. The altitude

recovery time between ACR firings was approximately 15 minutes.

4. TEST RESULTS

The comparison of the pretest and posttest measurements (reference

Table I) reveals that the coupons 2 through 8 subjected to the plume experi-

enced a change in absorptance but no change in emittance. The change in

absorptance value varied from . 03 to 18. 5%. Visual observation of the

coupons upon completion of the tests revealed no physical damage such as a

sandblasting or pitting effect. Coupon 1, which was left in the shipping

container, showed no change in absorptance or emissivity value indicating

that storage conditions had no effect on the tb-rmal paint. Coupons 9 and

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10, which were positioned in the altitude chamber but outside of the plume

boundary, showed no change in either absorptance or emittance value,

which indicated that ACR exhaust particle recirculation during an ACR

firing was not a problem when using a cryogenic panel downstream of the

rocket engine nozzle exit. Coupons 7 and 8, which represented the location

of the Transtage thermal-paint area with relation to the ACR roll engine

centerline, showed an insignificant increase in absorptance value which

varied from .03%6 to .04%6. Coupons 2 through 6 showed an increase in

absorptance value from . 04% to 18. 5%. The coupons showing the largest

increase in absorptance value were 2 and 3, which were 17% and 18.5%

respectively. These test specimens were located fairly close to the rocket I

engine nozzle exit. *1

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PHASE II TESTS - OPTICS AND SOLAR CELLS

1. TEST CONFIGURATION

The Phase II test hardware (reference Figure 9) consisted of two

major components: (1) a reference test specimen module of two optical

coupons and two solar cells, protected from the ACR exhaust particles by

the use of a solenoid-actuated protective shield; and (2) the main test

specimen module which incorporated six optical coupons, six solar cells

and a contamination coupon. The main test specimen module was position-

ed perpendicular to the centerline of the ACR engine for the direct plume

impingement tests. For the in situ measurements, the module was rotated

to the horizontal position. Rotation of the main test specimen module was

accomplished by the use of an AC motor in combination with mechanical

linkage.

The solar cells were bonded to a teflon disk (reference Figure 10) 1. 5

inches in diameter and . 250 inch thick. The cell coupons (reference Fig-

ure II) were secured to the specimen module by the use of a retainer ring.

The optical coupons (reference Figure 1Z) were 1.5 inches in diameter

and . 250 inch thick. These coupons were secured to the specimen moduleby the use of a cross-slit collimator as shown in Figure 13. The light

collimator was used to narrow down the acceptance angle of the photocellwhich is normally rated at 5%, but which can, based on past experiences,in some cases be as much at 15%. The inner dimensions of the cross-slit

collimator were 1. 75 inches in length and 1. 00 inch in diameter. The slot

widths were . 070 inch, and the interior of the unit was painted flat black to

minimize reflection.

A photocell was used to measure transmittance through the optics.

These data were recorded on a Leeds and Northrup Type "G" recorder.

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solar cell coupons. Standard illumination was used to obtain baseline

measurement of each test specimen, as well as test measurements follow-

ing 50, 100, 150 and 200 ACR firings at a pulse width of 200 milliseconds.

The types of laboratory equipment used for the pretest and posttest meas-urements of the optical coupons were a General Electric recording spectro-.

photometer which covered the 0. 38 to 0. 7-micron range and the Beckman

g! DK-2 ratio-recording spectrophotometer, in combination with a hydrogen

lamp and photomultiplier tube detector and a tungsten lamp and thermo-

couple detector. The hydrogen lamp r1otomultiplier tube detector covered

the 0. 25 to 0.35-micron and the 0.3 to 0.7-micron range where the tung-

sten lamp and thermocouple detector covered the 0.5 to 2. 5-micron range.

The laboratory equipment used for the pretest and posttest measurements

of the solar cells was an X-25-96-13-L solar simulator.

2. TEST POSITION

The Phase II test hardware (reference Figure 14) was positioned

5 feet and 9 feet downstream of the rocket nozzle exit. The xenon lampwas positioned directly above the reference and main test specimen mod-

ules. The location of the test specimens on the specimen modules for the

5- and 9-foot test positions are shown in Figures 15 and 16, respectively.

3. TEST CONDITIONSI]

During the Phase IItests, the solar cells and optical coupons for

each test position were maintained under a continuous vacuum condition for

a period of 264 hours and during this period of time were subjected to 200

ACR firings at an engine pulse width of 200 milliseconds. The test condi-

tions were the same for both the 5- and 9-foot test positions.

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The comparison of the optical pretest and posttest measurements

of the coupons located at the 5-foot test position (reference Figures 17

through 24) revealed a slight increase in optical transmittance. The per-

cent of increase varied, dependent upon location of the test specimen with

relation to the centerline of the ACR engine plume. For reference purposes,

the centerline of the plume was directed at the contamination coupon for

both the 5- and 9-foot test positicns. Since bore sighting equipment was

not available, a small tolerance could be expected since sighting was ac-

complished by visual means. Test coupons 1, 2, 6 and 7, which were

located fairly close to the centerline of the ACR plume, showed an increase

in transmittance from 3 to 7% at a wave length of 1. 4 microns. Test cou-

pons 3 and 8, located 10. 5 inches off from the centerline of the ACR engine,

showed an increase in transmittance from 1 to 2%. The protected specimens

4 and 9 showed no change in transmittance.. This increase in optical trans-

mittance was noted when taking in situ measurements following 50 ACR

firings. It was suspected that this condition was being caused by (1) photo-

cell and recording equipment shift characteristics, (2) hydrazine contam-

ination, or (3) ammonia contamination. It was determined to conduct

I laboratory tests to investigate this phenomenon.

I Following pretest measurements using a cross-slit collimator in com-I binatio-i with an incandescent light, one optical coupon was coated with N2 H4

and another was coated with anhydrous ammonia and allowed to dry at room

temperature. Upon completion of the drying operation, the optical coupons

were visually inspected. The hydrazine-coated optic revealed a uniformcoating of a very light white residue. The ammonia-coated optic revealed a

j residue coating which had a rainbow effect and was not uniform with regard

z. to concentration of the various colors. The posttest measurements of the

hydrazine-coated optics showed no change in transmittance value when com-pared with the pretest value. However, the ammonia-coated optical coupon

revealed an increase in transmittance from 5% to 17%, the larger value

experienced in areas where the rainbow e. ' - was more pronounced.2I

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should be pointed out that the application of contaminants on the laboratory

specimens were more severe than what would have been experienced during

actual ACR firings, especially with regard to uniformity. Discussion with

the Air Force Materials Laboratory (AFML) concerning the reason for the

increase in transmittance of the ammonia-coated coupons suggested that

ammonia residue acted as an antireflection coating.

FURi

The comparison of the pretest and posttest measurements of the solar

cells loacted at the 5-foot test position revealed, in some cases, an in-

crease and in others a decrease in solar cell output (reference Table II).

AFAPL personnel, responsible for the pretest and posttest measurementsf.! of the solar cells, have stated in their report that the percentage differences

between the preexposure and postexposure short-circuit current values

were primarily attributed to radiometric measurement inaccuracies. In

view of the phenomenon that occurred regarding the increase in transmit-

tance of the ammonia-coated optical coupon, identical tests were conducted

with solar cells. The results of the hydrazine experiment revealed a very

slight degradation of solar cell output by about 2 to 3%. The ammonia-

coated solar cell revealed an increase in power output by 4%. Based on the

results of these laboratory tests, it is possible that the Air Force Aero

Propulsion Laboratory (AFAPL) data are real to a certain degree.

The comparison of the optical pretest and posttest measurements forthe 9-foot test position revealed no difference in transmittance value

(reference Figures 25 through 32). The possible explanation for this could

be the reduction in the concentration of ammonia by a factor of 4 within the

ACR plume at a distance of 9 feet downstream of the rocket engine nozzle

exit under vacuum conditions.

The comparison of the solar cell pretest and posttest measurements(reference Table Ill) for the 9-foot test position revealed, in most cases, a

very slight decrease in solar cell output varying from-. 03 to -1. 4%.

Coupon 23 showed a 4% increase in power output. The protected reference

37

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icells 9 and Z5 revealed a slight change of -. 01 and -. 07, respectively. It is

possible that these test values are a combination of radiomnetric inaccuracies.

| "and to a small degree, AGR plume contamination.I

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SECTION VII

CONTAMINATION COUPON AND TEST RESULTS

The purpose of the contamination coupon was to collect ACR exhaust

contaminants and attempt to identify the type and quantities of the contami-nants using the collimetric analysis method. The size and shape of the

contamination coupon was identical to the optical coupons. The coupon was

secured to the main test specimen module by the use of a retainer ring and

was positioned on the centerline of the ACR engine for both the 5- and 9-foot

test positions. Upon completion of testing, the contamination coupon was

removed from the main test specimen module under a gaseous nitrogen

atmosphere and placed in a spe-ial container to minimize atmospheric

contamination during shipment to the laboratory for analysis. Due to the

low contamination level experienced during this effo'rt, it was not possible

to identify the contaminants, i. e., hydrazine and ammonia, below the level

of . I microgram, which was the lower limit of the Color-Ametric analysismethod. -

H -

i

IN

49

- -

I

SECTION VIII

CONCLUSIONS

E

Based on the test results derived from this effort, the monopropellant

I ACR plume is relatively clean.

Monopropellant ACR plume impingement on thermal-control coatings

I revealed a minor change in absorptance value, however, no change in

II

emittance value. The change in the initial ratio of tt/e of these coupons

I*

indicates that the ACR plume effects on the Transtage thermal paint are

insignificant.

Direct monopropellant ACR plume impingement on optics and solarcells did not have any serious effects on the operational characteristics of

this equipment at either the 5- or 9-foot distance downstream of the rocket

engine nozzle exit.

The results of this program indicate that the operation of the Transtage

ACR roll engines will not present a problem of contamination of onboardTranstage space-borne equipment.

I

Ii

- -A

50

TUn ciassti fi e

Secrit ClssiicaionDOCUMENT CONTROL DATA- R & D

(Security Classificat ion of title, body of abstract and indexinj annotation must be entered when the overall report Is Clas~llllD)1. ORIGINATING ACTIVITY (Corporate author) 2z,0 REPORT SECURITY CLASSIFICATION

F_________________ I

'I. Dept of the Air Force, AFSC IUnclassified

AFRPL, Edwvards, California 93523 J2b. GOUP

3. REPORT TITLE

MONOPROPELLANT EXHAUST CONTAMINATION INVESTIGATION

4. DESCRIPTIVE NOTES (Ty'pe *(report diltI)I-dot

5. AU THORIS) (First now*, middle Initial, last nsate)

MARTINKOVIC, PAUL J.

6. REPORT DATE 70. TOTAL NO. OF PAG ES j7b. NO. OF REFS

April 1969 56 NoneGa. CONTRACT OR GRANT NO. a*ORIGINATOR'S REPORT NUMOER(S)-

N/Ab. PROJECT No. 624AOODRV AFRPL- TR-69- 72

C. Scientific or Tech Area 9b. OTHER REPORT NO(S) (Any other numnbers 9,t may be aAeIn '.-

015900 S- cecraftthapr)d. 014700 Rocket Propellants_________________

1O DISTRIBUTION STATEMENT This d-)cume-nt is subject to special export controls and ea,transmittal to foreign governments or foreign nations may he made only with ip rio'zapproval of AFRPL (RPOR-STINFO), Edwards, California 93523.

II. SUPPLEMENTARY NOTES )-SPONSORING MILITARY &TIVITY

N/A ~Department of the Air Force, AFSCARRPL, Edwards, California

13. ABSTRACT- -

--4This report presents the results of the Mon,,-)rop~ellant Attitude Control Rkvckt.t(ACR) exhaust contamination investigation. the puarpose of this effort was todetermine ACR engine plume effects or, vehicle ,pace-borne equipment, i. e.,thermal control paint, solar cells and optics. Plume impingement tests were cn'n-.ducted at an altitude of 400, 000 feet, using a 25-lb-t.-raist monopropellant attitude-control rocket engine. The propellant was hydrazine (NWH&I) and the ignition sourct-was Shell 405 catalyst AI series of ZOO firings were condlucted at each test positionat an engine pulse width of 200 milliseconds. The analysis of the test data revealedthat the monopropellant ACR exhaust plume had little or no effect on the operatingcharacteristics of the space-borne equipment involved in the t-st program. FurthelMore, the monopropellant exhaust plume concerning contamination is relativelyclean compared to a bipropellant ACR plume using D;O%/A-50 and/or NDIC(VMMH.This comparison is based on past hip ropellant plume contamination test reldults.(

A

DD I oIi47

NOV 6 ~Unclassified ___

Security Classificitior =

J ~ ~ -

Security Classification

4.LINK A LINKS 1 L#N C 4

ROLE W T R~ W~ ROLE WT 3

W0E W MS

M.-onop ropellant ACR engine exhaust c ontarninati oSpace-borne equipment

S ik

AS

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