I. Şakraker, C.O. Asma, R. Torras-Nadal, O. Chazot20.06.2013

IPPW-10San Jose, CA, USA

Ground Testing of In-Flight Experiments of Re-Entry CubeSat QARMAN

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QARMAN: Real Flight TestbedQubeSat for Aerothermodynamic Research and

Measurements on AblatioN • Platform: Triple CubeSat with Ablative TPS• Mission: Atmospheric Entry Technology Demonstrator, Starting Altitude of 350 km• Launch: 2015 with QB50 Network

Why a Re-Entry “CubeSat”?→ Standardized small platform eliminates the only drawback: High Costs

→ Standard launch adaptors leading to highly flexible launch opportunities

→ If successful, it will be an affordable test platform for ablators, ceramics, sensors, trajectories, in-flight demonstrations, de-orbiting systems etc.

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Free Stream Measurements•Cold Wall Heat Flux•Static&Total Pressure•Spectrometer

Ablation Measurements•Pyrometer : Temperature •Radiometer : Temperature as f(ε)•Spectrometer : Species Detection•High Speed Camera•Infrared Camera•Thermocouples

VKI PlasmatronMeasurement Techniques

Courtesy: Helber

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VKI PlasmatronStagnation Point Heating by Fay&Riddell, 1958

weee

ww

edge

eeew hh

dsdUq

1.02/12/16.0Pr763.0

Local Heat Transfer Simulation Thermo-chemical equilibrium at stagnation point:

→ Subsonic plasmaFull simulation of stagnation region

te

fe HH t

efe pp t

efe

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Velocity Gradient, β, Duplication• β Definition differs in Subsonic and Hypersonic due to BL model• Unique to Trajectory and Vehicle Geometry

QARMAN Stagnation Line at 50 kmStagnation Line at Plasmatron

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Velocity Gradient, β, DuplicationConventional Method: Effective Radius

Modified Newtonian Theory

Spherical Bodies Blunt Bodies… ?

Ref: Lees1957

e

e

eff

flight ppR

381

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Velocity Gradient of Blunt BodiesBoison & Curtiss 1958

Geometries having bluntness parameter x*/r* less than 0.25 no longer obey MNT!

x*/r*

Velocity Gradient, β, Duplication

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Iterative Approach for Test Model Geometry Determination1- Pick a β

2- Determine the Reff Hypersonic (i.e MNT)3- Pass from Reff Hypersonic to Subsonic by matching the heat flux equation

ground

se

flights

SeffHeffPP

PRR

,,

1- Take the ICP Computation and calculate NDPs

2- Momentum equation provides the Reff Subsonic for ground facility

2

mod,

25.312

NDPNDPNDPNDP

RR elSeff

Extract Rmodel

Velocity Gradient, β, Duplication

@ 66 km Rm=5.8 mm@ 60 km Rm=94 mm

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QARMAN Flight Challenges

Flight Aerothermodynamic Database CFD++

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QARMAN: Sensor Accommodation

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Experimental PayloadsOverview

Payload Objective Sensor

XPL01 TPS Efficiency Temperature

XPL02 TPS & Environment Pressure

XPL03 Stability Pressure

XPL04 Shear Force, Transition Pressure, Skin Friction

XPL05 Off-Stagnation Temperature

Temperature

XPL06 Aerothermodynamic Environment and Radiation

Spectrometer

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Aerothermodynamic Instrumentation

Investigated Challenge Parameter to measure Sensor Phase

TPS Efficiency Temperature Distribution 12 x TC 3

TPS & Environment Pressure 2 x Pressure Sensor 3Stability Pressure 2 x Pressure Sensor 2b

Rarified Flow Conditions Low Pressure / Vacuum 1 x Vacuum Sensor 2a2b

Shear Force, Laminar to Turbulence Transition Skin Friction 4 x Preston Tube

2b

3

Off-Stagnation Temperature Evolution Temperature 10 x TC

2b

3

ATD Environment Species 1 x Spectrometer 3Intensity 1 x Photodiode 3

Phase 3 BudgetsTotal Mass: 319 gTotal Energy Consumption: 0.556 W hTotal Data Size: 21.57 KB

13Q1 Q2 Q3 Q4

29.00

31.00

33.00

35.00

37.00

39.00

41.00

Cork - PeakCork - IntegralASTERM - PeakASTERM - Integral

QARMAN TPS Selection Campaign - Enthalpy measured by REDES [MJ/kg]

Samples: QARMAN 1/2 ScaleMaterials: Cork P50 and ASTERMObjectives: 1- Monitor insulation properties

2- Monitor corner behaviorConditions:Constant Pressure 100 mbarTarget Heat Fluxes: 708; 1250; 1500; 1640 kW/m2

Total duration 80 s (20 s at each heat flux)

QARMAN TPS Selection Campaign

14Q1 Q2 Q3 Q4

29.00

31.00

33.00

35.00

37.00

39.00

41.00

Cork - PeakCork - IntegralASTERM - PeakASTERM - Integral

QARMAN TPS Selection Campaign - Enthalpy measured by REDES [MJ/kg]

Campaign Completed – 16 May 2013

Measurement Techniques:Free Stream Measurements- Water cooled calorimeter- Pitot Probe and Static Pressure Sensor- SpectrometerSample Measurements- Radiometer- Pyrometer- High Speed Camera- Thermocouples, 3 Type E + 1 Type K- 3 Spectrometers aligned from wall stagnation outward

QARMAN TPS Selection Campaign

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High Speed Camera → Recession & SwellingASTERMCork P50

Stag. Point: +1mmCorner: -7.4 mm

Stag. Point: -3.2mmCorner: -6.6 mm

QARMAN TPS Selection Campaign

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QARMAN TPS Selection CampaignASTERMCork P50

PyrometerRadiometer

Thermocouples

ASTERM

Cork

Tsurface = 2400 K Tsurface = 2500 K

Spectroscopic Characterization,Talk by B. Helber this afternoon

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Payloads: XPL01TPS Efficiency & Heating2 Thermal Plugs

Measurement Chain

Summary

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Thermal Plugs

60°

14mm

50mm

• 6 Thermocouples at 2.5, 5, 10, 20, 30, 40 mm• At 60° apart• 2 thermocouple per side trail• TC Type K or R inserted in U-shape

Payloads: XPL01TPS Efficiency & Heating

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XPL02: Stagnation Region & TPS PressureExoMars Concept

Diagonally 2 pressure taps

CFD: QARMAN @ 66km

Courtesy: G. Pinaud

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Stability determination (max. angles and rates) in-flight with• Pressure sensors• Accelerometers• Gyroscopes• Strain gauges

AeroSDS -> XPL03

Wall temperature T [K]

6-DoF simulations for osciallation frequency

CFD simulations for surface pressure, temperature and force determination

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Payloads: XPL06Radiation Study: Spectrometer

Spectrometer

Spectrometer support

structure

TPS bonding structure

TPS

Photometer

Light splitterOptical

path sleeve

Staged optical path

Measurement Setup

Presented by Bailet earlier today

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Questions?

isil.sakraker@vki.ac.be

QARMAN project is partially supported by the European Community Framework Programme 7, Grant Agreement no. 284427 in the framework of QB50 Project.

QARMAN Team: Thorsten Scholz, Gilles Bailet, Isil Sakraker, Cem O. Asma