Vision and Voyages for Planetary Science in the - Solar System ...

Uranus Orbiter with Entry Probe
SOURCE: NASA Mission Study (transmitted from Leonard A. Dudzinski, NASA
SMD/Planetary Science Division)
Scientific Objectives
• Investigate the interior structure, atmosphere, and
composition of Uranus
• Observe the Uranus satellite and ring systems
• Key science themes:
– Determine atmospheric zonal winds and structure
– Understand Uranus’s magnetosphere and interior
dynamo
– Determine noble gas abundances and isotopic ratios of
H, C, N, and O within Uranus’s atmosphere
– Determine the internal mass distribution of Uranus
– Determine horizontal distribution of atmospheric
thermal emission
– Observe Uranus’s satellites
Key Parameters: Descope Concept
• Uranus Orbiter and Entry Probe identical to original
proposed concept
• Mission identical, except
– Launch Mass: 2245 kg
– Launch Date: 2019 (on Atlas V 551)
• Descope assumptions
– No Solar‐Electric Propulsion (SEP) stage
– Chemical propulsion trajectory with gravity assist flybys
Uranus Orbiter and Probe (no SEP)
Key Challenges
• Demanding Entry Probe Mission
– High‐tempo operations just prior to orbit insertion
– Probe mass spectrometer
– High probe deceleration environment at entry
• Long Life for Orbiter
– Ensuring reliability and performance of ASRGs
• System Power
– Low power margins for this phase
• Sensitivity of Launch Opportunities to System Mass
– More trajectory analyses recommended
• High Magnetic Cleanliness for Orbiter
– Demanding requirement to reduce spacecraft magnetic
noise to 0.1 nT background
Key Cost Element Comparison
Cost Risk Analysis S‐Curve
PREPUBLICATION COPY—SUBJECT TO FURTHER EDITORIAL CORRECTION
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