Thermal balance test of Solar Orbiter EUI instrument Structural and Thermal Model

with 13 Solar constants

L. Jacques, J.-P. Halain, L. Rossi, M.-L. Hellin, P. Jamotton, S. Liebecq, A. Mazzoli, E. Renotte, P. Rochus

Centre Spatial de Liège, University of Liège, Belgium

Spacecraft Thermal Control Workshop, The Aerospace Corporation, El Segundo, March 26th, 2015

Outline

� What we do at CSL?

� Solar Orbiter

� EUI

� Test setup presentation

� Test results

� Test correlation

� Conclusions

slide 2

Outline

� What we do at CSL?

� Solar Orbiter

� EUI

� Test setup presentation

� Test results

� Test correlation

� Conclusions

slide 3

slide 4

Space Center in Liège, Belgium

University of Liège Research Center (since 1959)

Test facility for ESA:– Class 10000 & class 100 cleanrooms– 5 Vacuum chambers with optical bench (1.5 to

6.5m Ø)– 2 shakers in cleanroom (also cryo-vib)– Planck S/C, Herschel mirror, GAIA (PLM), XMM

telescope,…

Space instruments developed at CSL

EIT (SOHO), OM (XMM), FUV/SI (IMAGE), Sun baffle (C oRoT), HI (STEREO), PACS grating & DEC/MEC (Herschel), MIRI ( JWST), UVS SMA (JUNO), SWAP & LYRA (PROBA-2), EUI (Solar Orbiter) , ASPCIIS (PROBA-3),…

slide 5

Outline

� What we do at CSL?

� Solar Orbiter

� EUI

� Test setup presentation

� Test results

� Test correlation

� Conclusions

slide 6

Solar Orbiter key figures

� ESA M-Class mission� S/C currently in CDR� Oct-2018 launch� 0.28AU perihelion (17.5kW/m²), 1.47AU aphelion� 6 remote sensing instruments� 4 in-situ instruments� ~1800kg S/C (~190kg payload)� ~1kW� 400mm thick heat shield

slide 7

Outline

� What we do at CSL?

� Solar Orbiter

� EUI

� Test setup presentation

� Test results

� Test correlation

� Conclusions

slide 8

The Extreme-Ultraviolet Imager

� Remote sensing instrument with 3 channels� 2 High Resolution Imagers (100km resol.)

– HRILya at Lyman- α line (1216Å)– HRIEUV at 174Å

� 1 dual-band Full Sun Imager at 174Å and 304Å (900km resol.)

slide 9

FSI channel

HRILya channel

HRIEUV channel

HRIEUV entrance baffle

HRILya entrance baffle

FSI entrance baffle

HRIs Focal Plane Assembly

FSI Focal Plane Assembly(detector + Front End Electronics) FSI filter wheel

FSI primary mirror

HRIs primary mirror

HRIs secondary mirror

HRIEUV filter wheel

EUI in a nutshell

� 860 x 450 x 360 mm, ~15kg, 28W� CFRP-Alu honeycomb-CFRP sandwich structure� Ultrathin HRI EUV & FSI entrance filters (150nm thick Al.)� MgF2 coated HRI Lya entrance filter� Al. coated CFRP entrance baffles� Heat-pipes to cool down entrance filters, baffles a nd doors� -40°C cooled detectors (Al. Nitride package)

slide 10

S/C thermal interfaces

slide 11

S/C -y panel(conductive environment)

S/C Heat Shield

S/C heat shieldFeedthrough

Honeycomb bench

HRI FPAs

FEEdetector

HE CEHRIs MEHRIs

HRIs entrance baffle, door, filter assembly

FSI FPA

CEFSI MEFSI

Radiativeenvironment

QS

QB

FEEdetector

HE: Hot Element interface (+50°C)CE: Cold Element Interface (-50°C)ME: Medium Element Interface (+20°C)QB: IR load from S/C heat shield feedthroughs at ~300°CQS: Solar heat flux (17.5kW/m² at 0.28AU)TR: S/C cavity radiative environment (+50°C)TSRP: S/C conductive environment (+50°C)

HRIs heat pipes

� Conducts heat from HRIs filters, baffles & doors to HE� Two redundant heat-pipes� Al-NH3 heat pipes with H -shaped copper brazed interfaces� Copper goggles connecting doors, baffles, filters t o HP� Instrument orientation in TB test (also at S/C leve l)

slide 12

Ultrathin HRIEUV entrance filter

� 108 rejection of visible part of Solar spectrum

� Twice reinforced for structural & thermal– Local Nickel mesh grown onto Al foil– Clamped between Al. frames

slide 13

Ni mesh

Frame cell

Aluminium frame

2mm thickAluminiumframe

~30µm thick Ni meshFramepatternmatching

150nm thick Aluminium foil

Detector & Focal Plane Assembly

� 3k x 3k Active Pixel Sensor (developed for EUI)� Aluminum nitride package (T ° uniformity + CTE matching)� 3 Ti blades support (0.4mm thick for thermal decoup ling)

slide 14

Outline

� What we do at CSL?

� Solar Orbiter

� EUI

� Test setup presentation

� Test results

� Test correlation

� Conclusions

slide 15

Thermal balance test setup overview

slide 16

� Instrument STM upside-down� 3 Xe lamps� 3 feedthroughs� 220 sensors

Illumination setup

� 3 elliptical Cermax Xe arc-lamp + parabolic folding m irror

� Lamp spectrum + mirror spectral reflectivity

� Instrument coating absorptance adjusted

slide 17

400 600 800 1000 1200 1400 1600 1800 20000

0.5

1

Wavelength [nm]

rela

tive

spec

tral

inte

nsity

[A

U]

400 600 800 1000 1200 1400 1600 1800 20000

50

100

Wavelength [nm]

Inte

grat

ed in

tens

ity [

%]

∫ECermax(λ)dλ

∫ESun(λ)dλ

Illumination setup callibration

� Profile measured with picture & photodiode mapping

� Intensity measured with pyranometer

slide 18

17.5kW/m² @ 1.5m

slide 19

1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 25

10

15

20

25

30

35

40

Irra

dian

ce [

kW/m

²]

Distribution over a 50mm diam area

Avg

MaxMin

1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 25

6

7

8

9

10

distance from mirror [m]

Non

uni

form

ity w

rt a

vera

ge [

%]

(Max-Avg)/Avg

(Avg-Min)/Avg

Distance from folding mirror [m]

Distance from folding mirror [m]

17.5

Irradiance [kW/m²]

Non-uniformityover 50mm Ø area [%]

Divergence from pinhole spot size

slide 20

0 50 100 150 200 250 300 350 4000

50

100

150

200

250

300

350

50mm

50 100 150 200 250

10 20 30 40 50 60 700

0.2

0.4

0.6

0.8

1

X: 35.63Y: 0.278

x [mm]

X: 41.8Y: 0.2815

M1��

Array of pinholes

screen��

�

��

penumbra

��

�

� � atan�

2�� atan

�� � ��

2�� 1.4

��.�

��.�deg

Thermal IF setup

slide 21

LN2 panel + straps with heaters to provideCE, ME & HE temperatures

S/C cavity conductive environment

S/C heat shieldrepresentative feedthrough (hot & cold)with ceramic heaters & LN2 lines

Xe lamps

Outline

� What we do at CSL?

� Solar Orbiter

� EUI

� Test setup presentation

� Test results

� Test correlation

� Conclusions

slide 22

Test sequence & results overview

slide 23

01/09 01/10 01/11 01/12 01/13 01/14-200

-100

0

100

200

300

400

500

Time

Te

mp

era

ture

[°C

]

Baffle_EUV_front_-Y

THERMAL_IF_PANEL_1

Feedthrough_EUV_heater1_north

FPA_FSI_APS_1

08-Jan-2014 12:00:00 14-Jan-2014 00:00:00

close vacuum chamber and pumping

Thermal shroud PID tuning

Start hot case- 1 Fuse broke up- 1 S/C Heater lost

Switch ON lamps to 17.5kW/m²

Switch to LN2 on radiator and wait stabilization

- ≠ OP cases- Rotation of the

instrument:Heat pipe stall

- Hot NOP case- 3SC case- Start cold OP case

- ≠ OP cases- Start cold NOP

case

Back to ambient P and T

HRIEUV entrance baffle

Thermal IF panel

HRIEUV feedthroughFSI detector

Outline

� What we do at CSL?

� Solar Orbiter

� EUI

� Test setup presentation

� Test results

� Test correlation

� Conclusions

slide 24

Thermal model description

� Semi-transparent screen to model lamp flux non-uniformity

� Actual divergence � Actual absorption� 5219 nodes

slide 25

HRILya flux

Solar transmissivity

0

0.65

HRIEUV flux

Thermal model correlation

� RMS error (93 sensors): 1.2K (4.8K before correlati on)

� Error max: 2.8K

� Hot OP case results:

slide 26

Temperature [°C]

88

45

63

55

75

-50

200

60

Test heat balance

� 14.0W environment input, 10W dissipation

slide 27

QSRP = 0.0 W

QS [W] QB [W]

pupil 1.0

baffle 1.0 7.7 W VIS

filter 3.4 1.0 W IR QR = 3.9 W

door housing 2.3

QI

10.0 W

pupil 0.7

baffle 0.4 3.7 W VIS QCE,HRIs = 4.8 W

filter 1.7 0.5 W IR

door housing 0.9 QS+QB Q TOT14.0 W 24.0 W

pupil 0.4

baffle 0.0 0.5 W VIS

filter 0.0 0.0 W IR QME,HRIs = 2.9 W

door housing 0.0

Stru (goggles) & MLI 0.3 0.3 0.6 W

Total 12.1 W + 1.8 W = 14.0 W

QHE = 8.7 W

1.0HRI EUV 8.7 W

QME,FSI = 1.4 W

HRI Lya 4.2 W

QCE,FSI = 2.3 W

FSI 0.5 W0.0

0.5

IN OUT

Outline

� What we do at CSL?

� Solar Orbiter

� EUI

� Test setup presentation

� Test results

� Test correlation

� Conclusions

slide 28

Conclusions

� Model correlated

� Ultrathin filters survived

� Hot & cold thermo-elastic measurement performed & correlated

� Lessons learned for QM and FM thermal tests

� Further unit dedicated test:– Focal plane assemblies QM– Doors QM

slide 29

Thank you for your attention…

any question?

slide 30

Contact

Lionel Jacques, ljacques@ulg.ac.beThermal Engineer & PhD student

� Centre Spatial de Liège Liège Science Park Avenue Pré-AilyB-4031 Angleur Belgium http://www.csl.ulg.ac.be

� University of LiègeSpace Structures and Systems Lab1, Chemin des Chevreuils (B52/3)Liege, B-4000, Belgiumhttp://www.ltas-s3l.ulg.ac.be/

slide 31Spacecraft Thermal Control Workshop, The Aerospace Corporation, El Segundo, March 26th, 2015