0 250 - 250 500 Temperature ( C)

Pressure ( bars)

1000

100

10

1.0

0.1

0.01

Jupiter Probes

Venus Surface Exploration

CNSR

Europa Surface and Subsurface

Titan In-Situ

0 250 - 250 Temperature ( C)

Radiation( MRad)

10

1.0

0.1 Jupiter Probes

Europa Surface and Subsurface

Titan In-Situ

Earth

Earth

Venus Surface Exploration

CNSR

Pressure vs. Temperature Radiation vs. Temperature

500

Temperature, Pressure, and Radiation in Reference Missions

Mission Advanced Thermal Control

Technology

Pressure Vessel

Technology (100 bar)

High Temperature

(460 C) Components

Low Temperature

( - 180 C) Components

Corrosion Protection Technology

Radiation Hard

(> 5 Mrad) Components

Radiation Shielding

Technology (> 5 Mrad)

Venus Surface Exploration and Sample

Return

X X X X

Giant Planets Deep Probes X X X

Comets Nucleus Sample

Return X X

Titan In-Situ X X X

Europa Surface and Subsurface X X X X

Challenge: All reference missions have to survive and operate in extreme temperature, pressure, and radiation environments.

Summary of Reference Mission Technology Needs

Venus Dynamics Explorer

Objective: Obtain Measurements to explain the general circulation of the Venus atmosphere

• The cloud-level atmosphere (~70 km) rotates about 60 times faster than the planet’s slowly-rotating surface (4 days vs 242 day period)– The mechanisms responsible for this

superrotation have evaded theoretical explanation for >30 years

Venus Dynamics Explorer

Approach: Long-lived balloons and Orbiter• Network of 12 to 24 long-lived balloons

• Deployed between the surface and cloud tops at 3-4 latitudes (equatorial, mid, high)

• Time resolved measurements over ~1 week

• Discriminates eddies from mean flow• VLBI tracking, p, T, solar/thermal

radiation• Orbiter

• Required for communications/ tracking• UV and Near IR imaging spectrometers

for tracking the upper, middle, and lower clouds S- and/or X-band radio science package to retrieve density profile at 34 km and 100 km

Zonal Wind (m/s)

50

40

30

20

10

0

60

70

80

Alti

tude

(km

)

0 50 1007525

Balloon Deployment Approach

300

400

500

200

25

100

Temperature (C)

Technological Limits for Components

Hard solders melt at ~ 400 C

Soft solders melt at about ~180 CConnector problems start at ~150 C

TFE Teflon degenerates at 370 CSilicon electronics can’t

operate above 350 C

Water boils @ 1 atm at 100 C

Terrestrial Applications

Geothermal

Airplane

Military

Automotive

Venus

Jupiter Probes

Enhanced Oil Recovery

NA

SA

Nee

ds

Geothermal

Limit of commercial and military applications is

currently about 350 C

Oil WellsGas

Extreme high temperature/high pressure environments are unique to

NASA missions

High Temperature Limits of Conventional Components

Magnets and actuators operational limit is ~ 300-350 C

Power: Battery systems

-200 -100 0 100 200 300 400 500 600

Li/ CFx (-40 to 85)

Li/ S (Sion Power; Moltech) (-40 to 80)

Na/ S (220 to 360)

(Li;K;CsBr) Li(Si)/ FeS2 (350 to 550)

(LiF;Cl;Br) 44% Li(Si)/FeS2 (450 to 550)

Li ion (-40 to 60)

General Atomics (claimed 25 to 300)

Li(Mg)/ SOCl2 (70 to 200)

Li/ SOCl2 (-40 to 150)

aqueous (-20 to 65)

current survivability (-55 to 125)

Desired extreme range (-180 to 460)

Temperature (degrees C)

Thermal Control Technology Needs for Decadal Missions

Mission T/C Devices Applicable Environment

Comments

Venus Surface Exploration and Sample

Return

• Thermal insulation• Thermal storage•Thermal Switches•Active cooling systems•Active refrigeration

Over 460 C0 to 90 bar

Missions lasting more than a few hours on surface will need active refrigeration system

Giant Planets Deep Probes

•Thermal insulation, PCM storage, thermal switches, heat pipes

- 180 C to +380 C0.1 to 100 bar

Temperature and pressure increase with depth in the atmosphere

Comets Nucleus Sample Return

•Thermal insulation•PCM thermal storage•Thermal switches, Heat pipes

Generally cold, below -140 CNo environment

Waste heat from RPS can be used for thermal control of avionics

Titan In-Situ Explorer •Thermal insulation•PCM thermal storage•Thermal switches, Heat pipes, active cooling loops

-180 to -140 C0.1 to 1.5 bar

Long term operation on the surface requires radioisotope power source

Europa Surface and Subsurface

•Thermal insulation, thermal storage, active cooling loops

-160 C -`0.1 bar

Waste heat from RPS can be used for thermal control of avionics

All reference missions need advanced thermal control to survive and operate in extreme temperature and pressure.