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Full text of "NASA Technical Reports Server (NTRS) 20150018316: Analytical Methodology Used To Assess/Refine Observatory Thermal Vacuum Test Conditions For the Landsat 8 Data Continuity Mission"

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ANALYTICAL METHODOLOGY USED TO ASSESS/REFINE 
OBSERVATORY THERMAL VACUUM TEST CONDITIONS FOR 
THE LANDSAT 8 DATA CONTINUITY MISSION 


Louis Fantano 

NASA Goddard Space Flight Center 


GSFC- 2015 



Landsat 8 Thermal Team 



Spacecraft Bus 

Orbital Space Sciences Corporation (OSC) 

Billy Greenrock (Lead Thermal Engineer) 
Corey Roberts (Thermal Analyst) 

Operational Land Imager (OLI) 

Ball Aerospace & Technology Corporation (BATC) 
Michael East (Lead OLI Thermal Engineer) 


Thermal Infrared Sensor (TIRS) 

Goddard Space Flight Center (GSFC) 

Veronica Otera (TIRS Thermal Product Design Lead) 


Landsat Project Office 

Goddard Space Flight Center (GSFC) 

Lou Fantano (Lead Project Thermal Engineer) 


Many thanks to a great team ! 


TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


2 


ABSTRACT 


The Landsat 8 Data Continuity Mission, which is part of 
the United States Geologic Survey (USGS), launched 
February 11, 2013. 

A Landsat environmental test requirement mandated that 
test conditions bound worst-case flight thermal 
environments. 

This paper describes a rigorous analytical methodology 
applied to assess/refine proposed thermal vacuum test 
conditions and the issues encountered attempting to 
satisfy this requirement. 


TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


3 


Environmental Test Requirement 



3.6.3 Thermal Balance Qualification 

The adequacy of the thermal design and the capability of the thermal control system 
will be verified under simulated on-orbit worst case hot and worst case cold 
environments, and at least one other condition to be selected by the Contractor and 
approved by the GSFC LDCM Project. 

Consideration will be given for testing an "off nominal" case such as a safehold or a 
survival mode. 

LEVR-2 1 34 The test environments shall bound the worst hot and cold flight environments 
such that the test results directly validate the adequacy of the thermal design. 

An additional objective of the test is to verify and correlate the thermal model so it can be used 
to predict the behavior of the observatory under future non-tested conditions and/or flight 
conditions. It is preferable that the thermal balance test precede the thermal vacuum test so that 
the results of the balance test can be used to establish the temperature goals for the thermal 
vacuum test. 


TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


4 


Landsat 8 Instrument Suite 





BLANKETS NOT 
SHOWN 


Operational Land Imager (OLI) 


Spacecraft Bus 


Telescope 


Thermal Hardware 


-August 3-7, 2015 - Silver Spring, MD 


FPATCS (Thermal Control) 

Thermal Hardware 


• Ethane Heat Pipes 

• Ammonia Heat Pipes 

FPE TCS (Thermal Control) 


Star Tracker 
2X 


Load 


Control 


Unit 


S-band 

Antenna 


S-hand 

Transceiver 

2X 


Charge 

Control 

Unit 


X-band 

Transmitter 


FPE 


Focal Plane 
Electronics 


Thermal Infrared 


Sensor (TIRS) 


Telescope 

Radiator 

Cryocooler 
Radiator 


Hinges 


Sensor Unit 
Structure 


BB Calibrator 
Radiator 


Connector 


TFAWS 2015 


Solid 

State 
Recorder 


GPS Antenna 
4x 


Battery 


Integrated Coarse 
Electronics Sun Decryptor 
Module Sensors 


Magnetometer 

2X 


X-band 

Earth 

Coverage 

Antenna 

2X 


X-band 
Travelling 
Wave Tube 
Amplifier 
2X 


Thermal Hardware 


• Ethane Heat Pipes 

• Ammonia Heat Pipes 

• Cryocooler 

Earth Shield 


Mounting 
Flexures (to 
LDCM deck) 


Ammonia Heat Pipes 5 





Thermal Vacuum Test Set-Up 





Legend 

l 

SC+ZIR Plate 

2 

TIR5 +ZIR Plate 

3 

TIRS Hinge Line IR Plate 

4 

□ U +Z Snorkel IR Plate 

5 

OU -YSnorkel IR Plate 

6 

DU +X IR Plate 

7 

Deck Blanket Heater 

B 

TIR 5 Telescope Radiator LN 2 Plate 

9 

TIRSCrvocooler Radiator LN 2 Plate 

10 

DU FPA/FPE Radiator IH 2 PI ate 

11 

OU I5E Radiator LN 2 Plate 

12 

Contamination LIM 2 Plate 

13 

X-Band Load GN 2 Plates 


TV AC Configuration Summary 

• #T/Cs =426 

• = Test heater zones = 47 

• LN2 Zones = 6 

• GN2 Zones =1 

• QCMs 

• 2 TQCMs 

• 1CQCM 


TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


6 



Methodology Objectives 


Systematic process that inputs raw data directly from flight 
and TVAC models that generates quantitative measure of 
how the two environments compare. 

Create process that forces a detailed look at the model 
output to flush out analytical errors prior to test initiation. 

Generate summary output that facilitates communication 
to project management of environment comparison 
analyses results. 


TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


7 


Methodology Overview 


& 


Operational Land Imager 
(OLI) 


TMM 


Thermal Infrared Sensor 
(TIRS) 


TMM 


Observatory 

Integrator 


Nodal Group Correspondence 
1. Identify Major Elements 

(OLI, TIRS, BUS, PROP) 
2. MLI vs Non-MLI Groups 


SINDA QMAP FILES 
Steady State Solutions 
Cold, Hot, Safe Hold Flight Cases 
Cold, Hot, Safe Hold Test Cases 


Note: Models set up so that absorbed environmental loads, dissipated heat loads, 
and applied heater power are input to unique nodes. 


A) Verify steady state solution 

B) Calculate Group to Group 
Energy Balances 

C) Flight Versus TVAC Model 
Group Comparison 

D) Flight vs TVAC Power 
Dissipation Comparison 

E) Flight vs TVAC Environment 
Comparison 


For each case set pair (Flight /TVAC) : 

a) Assume groups coupled to space sink in the flight case have environmental inputs. 

b) Calculate QNet Flight (QAbsEnv-Qspace) for each of these groups 

c) Calculate QSink TVAC for each of these groups 

d) Compare QNet to QSink 

e) Sum heat flow differences to generate Flight to TVAC Comparison metric (with/without MLI) for each case set. 


TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


8 







w Calculate Group To Group Energy Balances 


Program input : Group Nodal Correspondence 
SINDA QMAP Data Dump 

b20c.qmap 

Tem p =c Corresponds to major element ID 

Power=WATTS / 

Area=in**2 / 

Boltz=3.661e-ll / 

Output=QMAP / 

End of Data / 

SUBMODEL'S 
99999$ BUS Space Node 

800010.800030.800050.800060.800080.800100.800110.800120.800130.800140.800150 $ BUS PZ Panel By AMT Radiating Surfaces 

800011.800021.800041.800051.800061.800101.800111.800121.800131.800141.800151 $ BUS PZ Panel MU 
80001-80015 $ BUS PZ PANEL PX COMPOSITE PANEL 

80016$ BUS PX STRINGER 
35000$ BUS AMT 1 radiator 
35001$ BUS AMT 1 mli 
3500$ BUS AMT 1 
35010$ BUS AMT 2 radiator 
35011$ BUS AMT 2 mli 
3501$ BUS AMT 2 

35220 $ BUS PZ Panel XBND Ant 1 radiating surface 
35221,35231$ BUS XBND Anti mli 
3522,3523$ BUS XBND Anti 

801020,801030,801040,801050,801060,801070,801080 $ BUS PZ Panel Mid, Xband/EPC radiating surfaces 
801011,801021,801041,801061,801081,801091,801101,801111,801121 $ BUS PZ Panel Mid MLI 
80101-80112$ BUS PZ PANEL MID (AL) 

35201$ BUS XBND TX1 mli 
3520$ BUS XBND TX1 
35211 $ BUS XBND TX 2 mli 
3521$ BUS XBND TX 2 
35301$ BUS TWTAEPC1 mli 
3530$ BUS TWTAEPC1 
35351 $ BUS TWTA EPC 2 mli 
3535 $ BUS TWTA EPC 2 

802010,802020,802030,802040,802050,802060 $ BUS PZ TWTA HP Panel Radiating Surfaces 
35330,35380 $ BUS PZ Panel PX Composite 
80201-80206 $ BUS PZ PANEL MID HP COMM PANEL 

35310, 35330 $ BUS TWTA 1 radiating surfaces 


Program Features 

- Validates nodal correspondence file 

-Verifies all nodes included in a group 
-Verifies no nodes included in two or more 
groups 

-Verifies boundary nodes are sole nodes in 
their respective groups. 

- Calculates Group To Group Energy Balances 
including group to group FAE radiation couplings. 

- Outputs .MAP file with all group to group energy 
balances. 


MLI nodes in separate groups 

Label ‘MLI’ included in Group Descriptor 


TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


9 



Output Example: Space Sink (Cold Ops Case) 



Begin Processing Grou 
********* ********* 

99999$ BUS Space 
99999 

Heat Sources: 

0 $ BUS 

Linear Con duction: 
QFlow Temp 

QMAP C 

Radiation Exchange: 

p 1 $ BUS Space Node 9/25/2012 12:38:09 AM 

1 of 649 =(CJ|C=(C=|CJ|C=(C=(CJ|C=(C=|CJ|C=|C=|CJ|=J|=J|=J|==(CS|CJ|C=(C=|CJ|C=(C=(CJ|C=(C=|CJ|C=|C=(CJ|C=(C=|CJ|CJ|C=(CJ|= 

Avg Temp = -273.0 (-273.0 to -273.0) 

CAP = 0.000 Group FOM = 0.000 

Space Node 999 

Group to group FAE radiation couplings 
^ — Listing ordered by heat flow 

^adSum^Fo GreupTll6030. 566489 IN**2 

QFlow^ 

QMap 

^femp 

C 

Fae 

IN**2 

Group Description 

4624.55 

22.5 

16535 

$ BUS SA PANEL 4 (FARTHEST FROM BUS) 2004 

4615.41 

22.7 

16465 

$ BUS SA PANEL 3 (MIDDLE PANEL 2) 2003 

4604.81 

23.3 

16284 

$ BUS SA PANEL 2 (MIDDLE PANEL 1) 2002 

3258.61 

16.2 

11711 

$ BUS SA PANEL 1 (CLOSEST TO BUS) 2001,2015 

641.3412 

-14.9 

3935.26078 

$ BUS Instrument Deck MU 10511-11251 

445.2307 

-27.6 

3316.8388 

$ TIRS TIRSES Earth SHIELD 300-359 300-359 

355.5366 

-14.7 

2238.07 

$ BUS BOTTOM CLOSEOUT BLANKET EXTERNAL MLI 13091,13211-13281 

346.603 

50 

867.98 

$ BUS SA PANEL 1 MU 20011 

249.0403 

-25.5 

1720.32 

$ BUS LV ADAPTER MLI 13011-13081 

235.0502 

-37.2 

2024.681 

$ OLI Cal Assy MLI (ext) 5951-5962 

203.232 

-27 

1551.2575 

$ TIRS TIRS ES MLI 403-438,450-454,470-474 403-438,450-454,470-474 

203.098 

-0.4 

1002 

$ BUS MLI -NY PANEL PX 860001 

187.623 

2.8 

884.6 

$ BUS RW 3,4 MLI 201 

181.239 

-1 

902.56 

$ BUS PZNY RWA MLI 301 

177.5098 

-5.8 

956.937 

$ BUS Battery Radiator 321001-321024 

156.3357 

-39 

1818.411 

$ OLI CO MLI Skirt (ext) 8940-8949 

130.802 

-9.8 

742.99 

$ BUS MLI - NZ PANEL PX 840001 

125.6774 

-16.4 

778.715 

$ BUS TOP CLOSEOUT MLI OUTER 16011,16021,16031,16041,16051,16061,16071,16081 

101.342 

-18.6 

659.19 

$ BUS RW 1,2 MLI 101 

100.114 

-0.1 

492 

$ BUS MLI -NYNZ PANEL NX 851001 

99.5171 

-12.2 

586.08 

$ BUS MLI -PZNY PANEL NX 871001 

99.0873 

-19.1 

834.326 

$ OLI PX Baseplate MLI 13701-13714 

98.8766 

0.7 

480.48 

$ BUS MLI -NYNZ PANEL PX 850001 

92.3374 

-26 

591.6734 

$ TIRS Closeout MLI [HSG_MLI] 4201-4222,14201-14222,24202,24210,104253-104254,10428 

87.8795 

-1.7 

442.54 

$ BUS SSR NZPY PANEL NX Radiating Surface 831010 

87.6418 

-17.5 

565.49688 

$ TIRS Structure, -Y/+X Slanted Truss [HSG_MLI_MINUSY] 14121-14134,14181-14194 

87.3406 

-9.9 

496.99 

$ BUS MLI -PZNY PANEL PX 870001 

85.6012 

-29.4 

662.75 

$ BUS PZPY PANEL NX MLI 811001 

84.8902 

-14.4 

517.12065 

$ TIRS MLI on +Z [HSG_MLI_PLUSZ] 4241,14321-14332,24241 

84.6184 

-33.6 

702.19 

$ BUS SSR mli 31101 

76.5692 

-33.3 

715.506 

$ OLI Ext MLI Skirt 6191-6196 

70.3451 

-24.7 

516.76 

$ OLI FPA Truss MLI 9390-9393 

65.509 

-13 

390.75 

$ BUS PZNY RWA Radiator 300 

63.7555 

-7.3 

348.91 

$ BUS MLI -NZ PANEL NX 841001 

62.7182 

-6 

339.2896 

$ BUS PZPY Panel Radiating surfaces 810010,810030,810060,810070,810080,810090,810120,1 

59.4747 

-44.4 

664.6252 

$ OLI MLI BP Edge MLI 13940-13950 

59.4182 

-14.4 

361.94 

$ BUS PZ Panel NX MLI 803011 

56.9927 

3.7 

265.352 

$ BUS SA LAUNCH SUPPORT, NZNY NX MLI 24101,24111,24121,24131 

55.1849 

-33.8 

459.22 

$ BUS IEM MLI 31001 

54.9987 

29.8 

178.31 

$ BUS SIRU Radiator 101 

54.2051 

-8.9 

283.019 

$ BUS IEM radiating surfaces 31000,31010,31020 


•Landsat Observatory Flight Model included 649 groups 

• Energy balance similar to shown calculated for each group 

•These data used as basis to compare flight versus test thermal 
environments. 


0.0012 

-40.5 

0.01091 $ 

TIRS Telescope Isolation System(TIS), Mid Ring, Telescope Shield l/F, [TELEALR1] 1761,1762 1 

0.001 

-87.1 

0.02163 $ 

TIRS Telescope MISC PARTS, RETAINERS, SPRINGS, ETC. [LENSAS34] 1751-1757 | 

0.0009 

-23 

0.00625 $ 

TIRS OSC Lid Man Hole Cover [ManHoleCoverMLI] 10808-10810,10836-10839,10850,20808- 

0.0008 

7.3 

0.00355 $ 

OLI Quaternary Mirror MLI 11481 

0.0008 

-24.9 

0.00581 $ 

TIRS CRYOCOOLER MOUNT CCM (Keel) (Key Group) [KEELRED] 931-985 

0.0007 

-25.4 

0.00493 $ 

TIRS MLI Tunnel [BellowsMLI] 10701-10711,20707,20711 

0.0007 

23.3 

0.00238 $ 

OLI Cal Assy Stim Lamp-2 7792 

0.0006 

17.8 

0.00225 $ 

OLI Secondary Mirror Silver 11201 

0.0006 

-17.2 

0.00377 $ 

TIRS Foot, -Y MLI [HSG_FT3_MLI] 4367,14367 

0.0005 

-111.8 

0.02020 $ 

TIRS APG BAR Telescope Link [TelescopeLink] 801-807,823-835,840-847 

0.0004 

9.2 

0.00179 $ 

OLI Cal Assy Shutter Wheel Motor &Mech 7600 

0.0004 

54.9 

0.00089 $ 

OLI Heater Plate 6 4806 

0.0004 

39.9 

0.00104 $ 

OLI Heater Plate 5 4805 

0.0003 

-19.8 

0.00203 $ 

TIRS Foot, +Z MLI [HSG_FT1_MLI] 4387,14387 

0.0003 

-86.7 

0.00655 $ 

TIRS Telescope Lens 3 [LENS3] 1736 

0.0003 

-77.8 

0.00485 $ 

TIRS 1 Layer Telescope Blanket [TELEMLI] 1783-1787 

0.0003 

-86.9 

0.00599 $ 

TIRS Telescope Aft Barrel TCB Sensor Htr Zone 1 (Key Group)[TBODY3] 1721-1726 


GROUP SUMMARY: 

QMAP 

Heat Sources : 

0 

Linear Conduction 

0 

Radiation Exchange : 

25050.94 

Heat Flow Balance : 

25050.94 


TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


10 


Flight Versus TVAC Model Group Comparison 


• Verify groups included in each model are consistent with 
test configuration. 

• Rigorous check performed to identify which sub-models included in 

each model. sample output 

SUMMARY COMPARISON - Cycle Thru TVAC - Compare to Flight 
17 Groups Not Coupled In TVAC File 

I Space Node 

5 BUS SA PANEL 1 MLI 

6 BUS SA PANEL 1 (CLOSEST TO BUS) 

7 BUS SA PANEL 2 (MIDDLE PANEL 1) 

8 BUS SA PANEL 3 (MIDDLE PANEL 2) 

9 BUS SA PANEL 4 (FARTHEST FROM BUS) 

10 BUS SA DAMPER 1 (CLOSEST TO BUS) 

II BUS SA DAMPER 2 (FARTHEST FROM BUS) 

12 SADA Wire bundle 

13 TIRS ES/SB EARTHSHIELD Upper ES to Wing Closeout 

14 TIRS ES/SB EARTHSHIELD Upper Wing 

15 TIRS ES/SB EARTHSHIELD Lower ES to Wing Closeout 

16 TIRS ES/SB EARTHSHIELD Lower Wing 

17 TIRS Strongback (Key Group) 


SUMMARY COMPARISON - Cycle Thru Flight QMAP - Compare To TVAC 
4 Groups Not Coupled In Flight File 

1 BUS OCXO 1 radiator 

2 BUS OCXO 2 radiator 

3 BUS DECRYPTOR radiator 

4 OLI SPACE NODE 

3 Groups In Fit File Not In TVAC File 

1 BUS SEP RING 

2 TIRS ES Earth SHIELD 300-359 

3 TIRS ES MLI 403-474 


27 Groups In TVAC File Not In Flight File 

1 TVAC CHAMBER END - MAN DOOR 

2 TVAC L-FRAME 

3 TVAC MLI - L-FRAME 

4 TVAC L-FRAME ADAPTOR PLATE 

5 TVAC MLI L-FRAME ADAPTOR PLATE 

6 TVAC STANCHIONS 


. Output removed 


Note: 

Due to rules associated with how SINDA generates QMAP files, nodes 
not included in the model could show up in the QMAP 
but not be coupled to anything. 


22 TVAC TIRS TELE RAD COLD PLATE BACKSIDE MLI 

23 TVAC PZ BUS IR PLATE 

24 TVAC PZ TIRS IR PLATE 

25 TVAC OLI PZ SNORKEL SHOWER CAP 

26 TVAC OLI PY SNORKEL SHOWER CAP 

27 TVAC TIRS NADIR SHOWER CAP 


TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


11 



Flight vs TVAC Power Dissipation Comparison 


• Critical to evaluate power dissipation assumptions 
embedded in flight and TVAC models for consistency. 


• In practice, with hardware as complex as an Observatory, 
it is not a simple matter to match powers exactly though 
that assumption is implicit in the test verification 
methodology. 


• Process To Evaluate Power Dissipation Assumption 

- Simple program inputs a power dissipation specification file that 
lists all groups with power dissipation. 

- Program cycles through MAP files, identifies all groups with non- 
zero power dissipation, and verifies that specification file has 
correctly identified all groups. 

- First iterate through TVAC files and then flight files. 


TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


12 



Flight vs TVAC Power Dissipation Comparison 



Hot Operations 

Cold Operations 

Safehold 


Flight 

TVAC 

Flight 

TVAC 

Flight 

TVAC 


Watts 

Watts 

Watts 

Watts 

Watts 

Watts 








Spacecraft Power 

703.9 

777.8 

520.3 

582.3 

319.2 

336.2 

OLI Dissipated Power 

6B.4 

68.4 

68.4 

68.4 

41.9 

48,7 

TIRS Sensor Dissipated Power 

88.7 

0.0 

67.5 

67.5 

0.0 

0.0 

TIRS MEB Dissipated Power 

71.0 

71.0 

40.0 

40.0 

0.0 

0.0 

TIRS CCE Dissipated Power 

53.9 

13.0 

23.0 

23.0 

0.0 

0.0 

Spacecraft Heaters 

34.3 

120.7 

194.3 

256.3 

304.2 

531.8 

Propulsion System 

1.5 

21.5 

56.6 

44.4 

91.1 

45.9 

OLI Heaters 

37.4 

64.9 

61.6 

78,5 

1.6 

29.7 


1059.1 

1137.3 

1031.7 

1160.4 

757.7 

992.3 




Hot Operations 

Cold Operations 

Safehold 


NODE 

Flight 

TVAC 

Flight 

TVAC 

Flight 

TVAC 

Oil DISSIPATED POWER 


Watts 

Watts 

Watts 

Watts 

Watts 

Watts 

OLI FPA ROIC POWER 

OLI. 9000 

1.4 

1.4 

1.4 

1.4 

O 

0 

OLI FPA BOX 

OLI.SOOO 

40.5 

40.5 

40.5 

40.5 

23.35 

26.04 

OLI FPA ANALOG CARD 

OLI .8007 

4.5 

4.5 

4.5 

4.5 

O 

0 

Oil ISE 

OLI. 6700 

22 

22 

22 

22 

13.51 

22.7 



63.4 

63.4 

63.4 

63.4 

41.9 

43. 7 









TIRS SENSOR DISSIPATED POWER 








TIRS FPE Boards 

TIRS. 69,70 

4.2 

0 

3.35 

3.35 

0 

0 

TIRS CRYOCOOLER TMU Compressor 

TIRS. 9 04, 9 07/9 

46.26 

0 

34.65 

34.65 

O 

0 

TIRS CRYOCOOLER TMU Displacer 

TIRS. 9 22, 9 25, 9 

35.74 

0 

27.35 

27.35 

0 

0 

TIRS SSM Encoder Remode Electronics 

TIRS. 1065 

0.7 

0 

0.65 

0.65 

0 

0 

TIRS SSM Encoder Read Head 

TIRS. 1072, 1075 

1.04 

0 

0.93 

0.93 

0 

0 

TIRS SSM Motor 

TIRS. 123 2, 123 3 

0.01 

0 

0.01 

0.01 

0 

0 

TIRS FPA QWIP Detector 

TIRS. 189 7- 139 9 

0.41 

0 

0.41 

0.41 

0 

0 

TIRS FPW1 l A 2R Heating 

TIRS. 19 21- 19 24 

0.3 

0 

0.1 

0.1 

0 

0 



33.7 

0 

67.5 

67.5 

0 

0 


TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


13 



Flight vs Test Environmental Comparison 

_.. . . . Key Definitions & Nomenclature 

Flight Thermal Environment J 

QAbs QSpace 

$ O 

Flight/TVAC Comparison 



For each group with view to space: 
QNet = QAbs - QSpace 


Delta = Heat difference for a particular 
group between flight and TVAC 
Delta=QTVRad - QNet 


Where: QNet = Flight Environment 

QAbs = Absorbed heat load from 
solar/earth heat sources 
QSpace = Heat radiated to space sink 


NetTot = Cumulated delta sum for each 
major Observatory hardware 
element. 

(OLI, TIRS, BUS, PROP) 


TVAC Thermal Environment 
QTVRad 


For each group with view to chamber/cold sink: 


Note: Test article conductively isolated 
from TVAC test support structure and 
guarded with zero-Q heaters. 


QTVRad = Heat radiated to TVAC Hardware 
( Chamber, Cold plates, etc.) 

TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


14 



Flight vs Test Environmental Comparison 


Cold 

Ops 

Output 

For 

BUS: 


COMPONENT DESCRIPTION 

FAE Spc 

TAvg 

QAbsEnv 

QSpace 

QNet 

TSnk 

TVSnk 

Temp 

QTVRad 

EnvTestQ 

DELTA 

NetTot 

NetXMLI 

TEST 

in**2 

C 

Watts 

Watts 

Watts 

C 

(C ) 

(C) 

(W) 

(W) 

(W) 

(W) 

(W) 

COND 

BUS SA PANEL 4 (FARTHEST FROM BUS) 20 

16535 

22.5 

4628.91 

4624.55 

4.36 

22.4 

GROUP NOT 

COUPLED 

IN TVAC MODEL 

0 





BUS SA PANEL 3 (MIDDLE PANEL 2) 2003 

16465 

22.7 

4625.63 

4615.41 

10.22 

22.6 

GROUP NOT 

COUPLED 

IN TVAC MODEL 

0 





BUS SA PANEL 2 (MIDDLE PANEL 1) 2002 

16284 

23.3 

4633.64 

4604.81 

28.83 

23.2 

GROUP NOT 

COUPLED 

IN TVAC MODEL 

0 





BUS SA PANEL 1 (CLOSEST TO BUS) 2001,2 

11711 

16.2 

3310.52 

3258.61 

51.91 

21.9 

GROUP NOT 

COUPLED 

IN TVAC MODEL 

0 





BUS Instrument Deck MLI 10511-11251 

3935.3 

-14.9 

645.96 

641.34 

4.61 

-13 

-26.5 

-34 

-39.47 

0 

-44.08 

-44.08 

0 

COLDER 

BUS BOTTOM CLOSEOUT BLANKET EXTERN 

2238.1 

-14.7 

339.73 

355.54 

-15.81 

-16.4 

-61.9 

-60.3 

-19.33 

0 

-3.52 

-47.6 

0 

COLDER 

BUS SA PANEL 1 MLI 20011 

868 

50 

410.21 

346.6 

63.61 

49.5 

GROUP NOT 

COUPLED 

IN TVAC MODEL 

0 





BUS LV ADAPTER MLI 13011-13081 

1720.3 

-25.5 

233.7 

249.04 

-15.34 

-22.7 

-58.9 

-59.2 

-19.47 

0 

-4.13 

-51.73 

0 

COLDER 

BUS MLI -NY PANEL PX 860001 

1002 

-0.4 

171.63 

203.1 

-31.47 

-1.2 

-69.9 

-70.1 

-10.21 

0 

21.26 

-30.47 

0 

WARMER 

BUS RW 3,4 MLI 201 

884.6 

2.8 

176.85 

187.62 

-10.78 

2 

-65.8 

-66.8 

-10.74 

0 

0.04 

-30.43 

0 

WARMER 

BUS PZNY RWA MLI 301 

902.6 

-1 

170.7 

181.24 

-10.54 

-1.6 

-62.4 

-62.5 

-10.2 

0 

0.34 

-30.09 

0 

WARMER 

BUS Battery Radiator 321001-321024 

956.9 

-5.8 

32.02 

177.51 

-145.49 

-97.9 

-62.2 

-2 

-107.48 

0 

38.01 

7.92 

38.01 

WARMER 

BUS MLI -NZ PANEL PX 840001 

743 

-9.8 

129.07 

130.8 

-1.74 

-10.4 

-63.5 

-65.9 

-10.14 

0 

-8.4 

-0.48 

38.01 

COLDER 

BUS TOP CLOSEOUT MLI OUTER 16011,16 

778.7 

-16.4 

111.86 

125.68 

-13.82 

-17.5 

-51.3 

-52.2 

-15.53 

0 

-1.71 

-2.19 

38.01 

COLDER 

BUS RW 1,2 MLI 101 

659.2 

-18.6 

97.94 

101.34 

-3.4 

-18.8 

-64.5 

-65.5 

-8.91 

0 

-5.51 

-7.7 

38.01 

COLDER 

BUS MLI - NYNZ PANEL NX 851001 

492 

-0.1 

97.63 

100.11 

-2.48 

-0.2 

-66.8 

-67.1 

-6.19 

0 

-3.71 

-11.41 

38.01 

COLDER 

BUS MLI -PZNY PANEL NX 871001 

586.1 

-12.2 

90.69 

99.52 

-8.83 

-12.3 

-59.1 

-59 

-2.55 

0 

6.28 

-5.13 

38.01 

WARMER 

BUS MLI -NYNZ PANEL PX 850001 

480.5 

0.7 

96.4 

98.88 

-2.47 

-0.5 

-65.7 

-67.9 

-5.84 

0 

-3.37 

-8.5 

38.01 

COLDER 

BUS SSR NZPY PANEL NX Radiating Surface 

442.5 

-1.7 

5.45 

87.88 

-82.43 

-102.1 

-66.6 

1.5 

-57.56 

0 

24.87 

16.37 

62.88 

WARMER 


BUS PZ Panel XBND Ant 2 radiating surface 

34.8 

-7.9 

6.29 

6.3 

-0.01 

-8.4 

-43.6 

-24.6 

-1.22 

0 

-1.21 

-61.75 

54.14 

COLDER 

BUS OCXO Mounting Plate radiating surface 

28.9 

3.3 

2.73 

6.17 

-3.44 

-40.8 

-55.6 

1.4 

-3.7 

0 

-0.26 

-62.01 

53.88 

COLDER 

BUS PZ Panel XBND Ant 1 radiating surface 

33 

-7.5 

6.1 

6.01 

0.08 

-6.7 

-39.3 

-25.7 

-0.92 

0 

-1 

-63.01 

52.88 

COLDER 

BUS SADA ELECTRONICS CONTROL UNIT (E 

22.9 

15.4 

5.87 

5.82 

0.05 

14.8 

-67.7 

-67.7 

-0.31 

0 

-0.36 

-63.37 

52.88 

COLDER 

BUS GPS RX 2 Radiator 33010 

20.1 

-3.2 

0.72 

3.91 

-3.19 

-53.5 

-62.1 

-3.1 

-2.57 

0 

0.62 

-62.75 

53.5 

WARMER 

BUS GPS RX 1 Radiator 33000 

19.1 

-0.5 

0.66 

3.87 

-3.2 

-49.2 

-61.7 

-3.5 

-2.4 

0 

0.8 

-61.95 

54.3 

WARMER 

BUS PY Panel Battery Radiator 32110 

34.3 

-40.2 

4.15 

3.7 

0.45 

-39.1 

-62 

-62.8 

-0.21 

0 

-0.66 

-62.61 

53.64 

COLDER 

BUS DECRYPTOR mli 35601 

29.3 

-32.8 

3.25 

3.58 

-0.33 

-32.8 

-52.5 

-52.4 

-0.35 

0 

-0.02 

-62.63 

53.64 

COLDER 

BUS STAR CAMERA 1 BAFFLE 3120 

23.6 

-20.4 

2.4 

3.53 

-1.12 

-24.6 

-44.6 

-36.6 

-1.32 

0 

-0.2 

-62.83 

53.44 

COLDER 

BUS PZ Panel PX Composite 35330,35380 

20.2 

-11.3 

2.22 

3.48 

-1.26 

-29.4 

-30.5 

-2.2 

-1.74 

0 

-0.48 

-63.31 

52.96 

COLDER 

BUS NYNZ PANEL Radiating surface 85108( 

17.7 

-6.5 

0.75 

3.28 

-2.54 

-40.3 

-54.7 

-9.4 

-2.03 

0 

0.51 

-62.8 

53.47 

WARMER 

BUS GPS RX1 mli 33001 

15.7 

0.1 

3.09 

3.2 

-0.11 

0 

-65.9 

-65.9 

-0.19 

0 

-0.08 

-62.88 

53.47 

COLDER 

BUS Battery Radiator MLI 32101 

65.1 

-82 

2.55 

3.18 

-0.63 

-81.6 

-71.9 

-72.3 

-0.44 

0 

0.19 

-62.69 

53.47 

WARMER 

BUS GPS RX 2 mli 33011 

15 

-0.6 

3.03 

3.02 

0.01 

-0.5 

-65.1 

-65.4 

-0.2 

0 

-0.21 

-62.9 

53.47 

COLDER 

BUS STAR CAMERA 2 BAFFLE 3220 

23.5 

-30.8 

1.96 

2.97 

-1.01 

-35.7 

-49.1 

-41.2 

-1.14 

0 

-0.13 

-63.03 

53.34 

COLDER 

BUS TAM 1 mli 33201 

16.5 

-15.1 

2.62 

2.67 

-0.06 

-15.1 

-41 

-41.1 

-0.15 

0 

-0.09 

-63.12 

53.34 

COLDER 

BUS TAM 2 mli 33211 

15.7 

-13.2 

2.62 

2.63 

0 

-13.2 

-41.3 

-41.3 

-0.14 

0 

-0.14 

(^26) 

C53^> 

COLDER 


T f 'f 

Equivalent Heat Sink calculated for reference. 


TFAWS 2015 - August 3-7, 2015 - Silver Spring, MD Summation 15 

Columns 


Process Products 



FLIGHT VERSUS TEST ENVIRONMENT COMPARISON (TVAC_HTR_MOD-80CB) 
EXPRESSED AS FUNCTION OF ABSOLUTE HEAT FLOW 


Hot Operations 
TVAC - Flight 
RAD&MLI RAD 

W W 


Cold Operations 
TVAC - Flight 
RAD&MLI RAD 

W W 


Safehold 
TVAC - Flight 
RAD&MLI RAD 

W W 


BUS 

OLI 

TIRS 

PROP 


-45 82 

28 6 

In Dry Out Mode 
-8 


63 

4fT 

-23 

-7 



0 

1 

2 


FLIGHT VERSUS TEST ENVIRONMENT COMPARISON 
EXPRESSED AS PERCENTAGE OF TEST ARTICLE ENERGY BALANCE 


Hot Operations 
TVAC - Flight 
RAD&MLI RAD 


% 


% 


Cold Operations 
TVAC - Flight 
RAD&MLI RAD 


% 


% 


Safehold 
TVAC - Flight 
RAD&MLI RAD 


% 


% 


BUS 

OLI 

TIRS 

PROP 


-8 14 

27 6 

In Dry Out Mode 
-211 


-19 

45 

-29 

-143 


7 

-102 


-21 

25 

-73 

-60 


3 

0 

2 



[ 


] 


Note: Positive value means the test environment is warmer than the flight environment. 

Summation columns for each major hardware element reported 

(BUS cold operations case comparison from previous page circled). 

Set 10% energy balance threshold and claimed satisfaction of the test requirement for 
all components and cases except OLI (11%) in the cold operations case. 


TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


16 


Issues Encountered 


• “Bounding” thermal environment easier said than done ... 

- Complicated hardware and many components with different 
temperature requirements. 

• For Landsat-8, instrument survival temperature 
requirements limited how cold the chamber cold wall 
could be (ended up at -100 C for cold cases). 

- Understandable since cold case includes orbital environmental 
flux inputs whereas the chamber has none. 

• Heaters typically not installed at locations where the minimum cold 
case maintains temperatures above requirements. 

• In the chamber, these locations driven by the local (typically cold wall) 
thermal environment which can be colder. 

• Projects that include a bounding design case TVAC test requirement 
should consider designing for a colder test environment (flight and/or 
test heaters). 



TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


17 


At The End Of The Day 


• What is important ... 

- Recognize shared goals to exercise models and perform a 
successful Observatory thermal vacuum test campaign. 

- Develop trust and maintain good communication between teams. 

- Minimize time required for Contractor to provide data. 

- Very helpful to quantitatively compare test and flight thermal 
environments so that the most sensible test conditions are 
applied. 

- Landsat-8 thermal vacuum test campaign ended up being very 
successful with few (if any) modeling issues identified. 



TFAWS 201 5 - August 3-7, 201 5 - Silver Spring, MD 


18