80 likes | 268 Vues
Temperature, Pressure, and Radiation in Reference Missions. Pressure vs. Temperature. Radiation vs. Temperature. Pressure ( bars). Radiation( MRad). 1000. 10. Europa Surface and Subsurface. Jupiter Probes. 100. 10. 1.0. Venus Surface Exploration. Titan In-Situ. Earth. 1.0.
E N D
Temperature, Pressure, and Radiation in Reference Missions Pressure vs. Temperature Radiation vs. Temperature Pressure ( bars) Radiation( MRad) 1000 10 Europa Surface and Subsurface Jupiter Probes 100 10 1.0 Venus Surface Exploration Titan In-Situ Earth 1.0 0.1 0.1 Jupiter Probes Europa Surface and Subsurface Venus Surface Exploration Titan In-Situ 0.01 CNSR Earth CNSR - 250 250 - 250 250 500 500 0 0 Temperature ( C) Temperature ( C)
Summary of Reference Mission Technology Needs Challenge: All reference missions have to survive and operate in extreme temperature, pressure, and radiation environments.
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
80 70 60 Altitude (km) 50 40 30 20 10 0 0 25 50 75 100 Balloon Deployment Approach Zonal Wind (m/s)
Venus Enhanced Oil Recovery Airplane High Temperature Limits of Conventional Components Technological Limits for Components Extreme high temperature/high pressure environments are unique to NASA missions 500 Temperature (C) NASA Needs Jupiter Probes 400 Hard solders melt at ~ 400 C TFE Teflon degenerates at 370 C Silicon electronics can’t operate above 350 C Limit of commercial and military applications is currently about 350 C Geothermal Magnets and actuators operational limit is ~ 300-350 C 300 Geothermal Automotive 200 Gas Soft solders melt at about ~180 C Connector problems start at ~150 C Oil Wells Water boils @ 1 atm at 100 C 100 Terrestrial Applications Military 25
Thermal Control Technology Needs for Decadal Missions All reference missions need advanced thermal control to survive and operate in extreme temperature and pressure.