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
AdvancedThermalControlTechnology
PressureVesselTechnology(100 bar)
HighTemperature(460 C)Components
LowTemperature( - 180 C)Components
CorrosionProtectionTechnology
RadiationHard
(> 5 Mrad)Components
RadiationShieldingTechnology
(> 5 Mrad)
Venus SurfaceExplorationand SampleReturn
X
X
X
X
Giant PlanetsDeep Probes
X
X
X
CometsNucleus SampleReturn
X
X
Titan In-Situ
X
X
X
Europa Surfaceand Subsurface
X
X
X
X
Challenge: All reference missions have to survive and operate in extremetemperature, pressure, and radiation environments.
Summary of Reference Mission Technology Needs
Venus Dynamics Explorer
Objective: Obtain Measurements toexplain the general circulation ofthe Venus atmosphere
•The cloud-level atmosphere(~70 km) rotates about 60 timesfaster than the planet’s slowly-rotating surface (4 days vs 242day period)
–The mechanisms responsible for thissuperrotation have evaded theoreticalexplanation for >30 years
Venus Dynamics Explorer
Approach: Long-lived balloons and Orbiter
•Network of 12 to 24 long-lived balloons
•Deployed between the surface andcloud tops at 3-4 latitudes (equatorial,mid, high)
•Time resolved measurements over ~1week
•Discriminates eddies from mean flow
•VLBI tracking, p, T, solar/thermalradiation
•Orbiter
•Required for communications/ tracking
•UV and Near IR imaging spectrometersfor tracking the upper, middle, andlower clouds S- and/or X-band radioscience package to retrieve densityprofile at 34 km and 100 km
Zonal Wind (m/s)
50
40
30
20
10
0
60
70
80
Altitude (km)
0
50
100
75
25
Balloon Deployment Approach
300
400
500
200
25
100
Temperature (C)
Technological Limits forComponents
Hard solders melt at ~ 400 C
Soft solders melt at about ~180 C
Connector problems start at ~150 C
TFE Teflon degenerates at 370 C
Silicon electronics can’toperate above 350 C
Water boils @ 1 atm at 100 C
Terrestrial Applications
Geothermal
Airplane
Military
Automotive
Venus
Jupiter
Probes
Enhanced OilRecovery
NASA Needs
Geothermal
Limit of commercial andmilitary applications iscurrently about 350 C
Oil Wells
Gas
Extreme hightemperature/high pressureenvironments are unique toNASA missions
High Temperature Limits of Conventional Components
Magnets and actuators operationallimit is ~ 300-350 C
Power: Battery systems
Thermal Control Technology Needs for Decadal Missions
Mission
T/C Devices
ApplicableEnvironment
Comments
Venus SurfaceExploration and SampleReturn
• Thermal insulation
• Thermal storage
•Thermal Switches
•Active cooling systems
•Active refrigeration
Over 460 C
0 to 90 bar
Missions lasting more thana few hours on surface willneed active refrigerationsystem
Giant Planets DeepProbes
•Thermal insulation, PCMstorage, thermal switches,heat pipes
- 180 C to +380 C
0.1 to 100 bar
Temperature and pressureincrease with depth in theatmosphere
Comets Nucleus SampleReturn
•Thermal insulation
•PCM thermal storage
•Thermal switches, Heat pipes
Generally cold,below -140 C
No environment
Waste heat from RPS canbe used for thermal controlof avionics
Titan In-Situ Explorer
•Thermal insulation
•PCM thermal storage
•Thermal switches, Heatpipes, active cooling loops
-180 to -140 C
0.1 to 1.5 bar
Long term operation on thesurface requiresradioisotope power source
Europa Surface andSubsurface
•Thermal insulation, thermalstorage, active cooling loops
-160 C
-`0.1 bar
Waste heat from RPS canbe used for thermal controlof avionics
All reference missions need advanced thermal control to survive andoperate in extreme temperature and pressure.