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

Uranus Orbiter with Solar‐Electric Propulsion and
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
• Orbiter Payload
– Wide‐ and Narrow‐Angle Imagers
– Visible/Near‐Infrared Mapping Spectrometer
– Ultraviolet Imaging Spectrograph
– Mid‐Infrared Thermal Detector
– Plasma Instruments(2), Magnetometer, Ultra‐stable
Oscillator
• Entry Probe Payload
– Mass Spectrometer
– Atmospheric Structure Instrument, Nephelometer
– Ultra‐stable Oscillator
• Three Advanced Stirling Radioisotope Generators
• Launch Mass: 4129 kg
• Launch Date: 2020 (on Atlas V 531)
• Orbit: 1.3 Ru x 51.3 Ru, 97.7 deg inclined orbit + Satellite tour
Uranus Orbiter and Probe
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 (15.4 years) for Orbiter
– Ensuring reliability and performance of ASRGs
• High Magnetic Cleanliness for Orbiter
– Demanding requirement to reduce spacecraft magnetic
noise to 0.1 nT background
• System Mass and Power
– Low‐mass and ‐power margins for this phase
– High mass multiplying factor from large propulsion
delta‐V requirements
Key Cost Element Comparison
Cost Risk Analysis S‐Curve
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