TRS-1 Payload Options Thomas R. Spilker, Jet Propulsion Laboratory / CIT 2011 June 8 8th International Planetary Probes Workshop Portsmouth, Virginia, USA for Future Entry Probe Missions

TRS-2 Organization PSDS recommended entry probe missions PSDS recommended entry probe missions Mission science objectives and instrumentation options Mission science objectives and instrumentation options – (With a couple of diversions for explanations)

TRS-3 PSDS Recommendations for Future Entry Probe Missions Saturn probe in NASA’s New Frontiers Program Saturn probe in NASA’s New Frontiers Program Ice giant (Uranus or Neptune) orbiter with probe Ice giant (Uranus or Neptune) orbiter with probe Orbiter and probe to the other ice giant; next decade Orbiter and probe to the other ice giant; next decade Venus In-Situ Explorer (VISE) in New Frontiers Program Venus In-Situ Explorer (VISE) in New Frontiers Program Holdover from previous PSDS Holdover from previous PSDS Primarily landed science, but measurements on the way down Primarily landed science, but measurements on the way down Venus Climate Mission (VCM), flagship Venus Climate Mission (VCM), flagship Includes “a balloon, a mini-probe, and two drop sondes” Includes “a balloon, a mini-probe, and two drop sondes”

TRS-4 Saturn Entry Probe Science Objectives and Instrumentation Options Tier 1 Objectives (measured to the 5-10 bar level) Tier 1 Objectives (measured to the 5-10 bar level) Composition Composition Abundances of noble gases He, Ne, Ar, Kr, and Xe (and their isotopes!) Abundances of noble gases He, Ne, Ar, Kr, and Xe (and their isotopes!) Isotopic ratios of H, C, N, and O Isotopic ratios of H, C, N, and O Atmospheric structure (T, P, and mass density vs. depth) Atmospheric structure (T, P, and mass density vs. depth)

TRS-5 Saturn Entry Probe Science Objectives and Instrumentation Options Tier 1 Objectives (measured to the 5-10 bar level) Tier 1 Objectives (measured to the 5-10 bar level) Composition Composition Abundances of noble gases He, Ne, Ar, Kr, and Xe (and their isotopes!) Abundances of noble gases He, Ne, Ar, Kr, and Xe (and their isotopes!) Isotopic ratios of H, C, N, and O Isotopic ratios of H, C, N, and O Atmospheric structure (T, P, and mass density vs. depth) Atmospheric structure (T, P, and mass density vs. depth)  Neutral Mass Spectrometer (NMS) Wide, continuous mass range Typically low to medium mass resolution

TRS-6 Saturn Entry Probe Science Objectives and Instrumentation Options Tier 1 Objectives (measured to the 5-10 bar level) Tier 1 Objectives (measured to the 5-10 bar level) Composition Composition Abundances of noble gases He, Ne, Ar, Kr, and Xe (and their isotopes!) Abundances of noble gases He, Ne, Ar, Kr, and Xe (and their isotopes!) Isotopic ratios of H, C, N, and O Isotopic ratios of H, C, N, and O Atmospheric structure (T, P, and mass density vs. depth) Atmospheric structure (T, P, and mass density vs. depth)  Neutral Mass Spectrometer (NMS) Wide, continuous mass range Typically low to medium mass resolution  Tunable Laser Spectrometer (TLS) Small number of predetermined species Very high mass resolution

TRS-7 Saturn Entry Probe Science Objectives and Instrumentation Options Tier 1 Objectives (measured to the 5-10 bar level) Tier 1 Objectives (measured to the 5-10 bar level) Composition Composition Abundances of noble gases He, Ne, Ar, Kr, and Xe (and their isotopes!) Abundances of noble gases He, Ne, Ar, Kr, and Xe (and their isotopes!) Isotopic ratios of H, C, N, and O Isotopic ratios of H, C, N, and O Atmospheric structure (T, P, and mass density vs. depth) Atmospheric structure (T, P, and mass density vs. depth)  Neutral Mass Spectrometer (NMS) Wide, continuous mass range Typically low to medium mass resolution  Tunable Laser Spectrometer (TLS) Small number of predetermined species Very high mass resolution  Atmospheric Structure Instrument (ASI) package System of thermometers, barometers, & accelerometers Very lightweight, low power, low data volume

TRS-8 PSDS Draft Report Saturn Entry Probe Science Objectives Tier 2 Objectives Tier 2 Objectives Vertical profile of zonal winds at the probe entry location Vertical profile of zonal winds at the probe entry location Location, density, and composition of clouds as a function of depth Location, density, and composition of clouds as a function of depth Variability of atmospheric structure and clouds in two locations Variability of atmospheric structure and clouds in two locations Vertical profile of water abundance at the probe entry location Vertical profile of water abundance at the probe entry location Precision isotope measurements for light elements in simple molecules Precision isotope measurements for light elements in simple molecules Elements such as N, O, & S Elements such as N, O, & S Omits measurements of diagnostic species such as CO, PH 3, AsH 3, SiH 4, GeH 4

TRS-9 PSDS Draft Report Saturn Entry Probe Science Objectives Tier 2 Objectives Tier 2 Objectives Vertical profile of zonal winds at the probe entry location Vertical profile of zonal winds at the probe entry location Location, density, and composition of clouds as a function of depth Location, density, and composition of clouds as a function of depth Variability of atmospheric structure and clouds in two locations Variability of atmospheric structure and clouds in two locations Vertical profile of water abundance at the probe entry location Vertical profile of water abundance at the probe entry location Precision isotope measurements for light elements in simple molecules Precision isotope measurements for light elements in simple molecules Elements such as N, O, & S Elements such as N, O, & S Omits measurements of diagnostic species such as CO, PH 3, AsH 3, SiH 4, GeH 4  Doppler Wind Experiment (2 USOs) (Atkinson talk yesterday)

TRS-10 PSDS Draft Report Saturn Entry Probe Science Objectives Tier 2 Objectives Tier 2 Objectives Vertical profile of zonal winds at the probe entry location Vertical profile of zonal winds at the probe entry location Location, density, and composition of clouds as a function of depth Location, density, and composition of clouds as a function of depth Variability of atmospheric structure and clouds in two locations Variability of atmospheric structure and clouds in two locations Vertical profile of water abundance at the probe entry location Vertical profile of water abundance at the probe entry location Precision isotope measurements for light elements in simple molecules Precision isotope measurements for light elements in simple molecules Elements such as N, O, & S Elements such as N, O, & S Omits measurements of diagnostic species such as CO, PH 3, AsH 3, SiH 4, GeH 4  Doppler Wind Experiment (2 USOs) (Atkinson talk yesterday)  Nephelometer

TRS-11 What is a Nephelometer? Laser Light Sensor Clear Air Very few photons scatter to sensor

TRS-12 What is a Nephelometer? Laser Cloud particles scatter some photons directly back to sensor

TRS-13 What is a Nephelometer? Laser Some photons multiple- scatter to sensor

TRS-14 What is a Nephelometer? Laser Many photons scatter hither and yon

TRS-15 PSDS Draft Report Saturn Entry Probe Science Objectives Tier 2 Objectives Tier 2 Objectives Vertical profile of zonal winds at the probe entry location Vertical profile of zonal winds at the probe entry location Location, density, and composition of clouds as a function of depth Location, density, and composition of clouds as a function of depth Variability of atmospheric structure and clouds in two locations Variability of atmospheric structure and clouds in two locations Vertical profile of water abundance at the probe entry location Vertical profile of water abundance at the probe entry location Precision isotope measurements for light elements in simple molecules Precision isotope measurements for light elements in simple molecules Elements such as N, O, & S Elements such as N, O, & S Omits measurements of diagnostic species such as CO, PH 3, AsH 3, SiH 4, GeH 4  Doppler Wind Experiment (2 USOs) (Atkinson talk yesterday)  Nephelometer (Simple? Polarization?)

TRS-16 Flow-Induced Nephelometer Error

TRS-17 Flow-Induced Nephelometer Error

TRS-18 Flow-Induced Nephelometer Error Shock

TRS-19 Flow-Induced Nephelometer Error Shock Expansion wave

TRS-20 Flow-Induced Nephelometer Error Condensation

TRS-21 Flow-Induced Nephelometer Error

TRS-22 Flow-Induced Nephelometer Error Instruments can be fooled! Instruments can be fooled! Not just nephelometers: thermometers, barometers -- anything looking at the gas flowing by the descent module Not just nephelometers: thermometers, barometers -- anything looking at the gas flowing by the descent module When designing descent module configuration and payload mounting, you must consider the dynamics of the airflow! When designing descent module configuration and payload mounting, you must consider the dynamics of the airflow!

TRS-23 PSDS Draft Report Saturn Entry Probe Science Objectives Tier 2 Objectives Tier 2 Objectives Vertical profile of zonal winds at the probe entry location Vertical profile of zonal winds at the probe entry location Location, density, and composition of clouds as a function of depth Location, density, and composition of clouds as a function of depth Variability of atmospheric structure and clouds in two locations Variability of atmospheric structure and clouds in two locations Vertical profile of water abundance at the probe entry location Vertical profile of water abundance at the probe entry location Precision isotope measurements for light elements in simple molecules Precision isotope measurements for light elements in simple molecules Elements such as N, O, & S Elements such as N, O, & S Omits measurements of diagnostic species such as CO, PH 3, AsH 3, SiH 4, GeH 4  Doppler Wind Experiment (2 USOs) (Atkinson talk yesterday)  Nephelometer (Simple? Polarization?)

TRS-24 PSDS Draft Report Saturn Entry Probe Science Objectives Tier 2 Objectives Tier 2 Objectives Vertical profile of zonal winds at the probe entry location Vertical profile of zonal winds at the probe entry location Location, density, and composition of clouds as a function of depth Location, density, and composition of clouds as a function of depth Variability of atmospheric structure and clouds in two locations Variability of atmospheric structure and clouds in two locations Vertical profile of water abundance at the probe entry location Vertical profile of water abundance at the probe entry location Precision isotope measurements for light elements in simple molecules Precision isotope measurements for light elements in simple molecules Elements such as N, O, & S Elements such as N, O, & S Omits measurements of diagnostic species such as CO, PH 3, AsH 3, SiH 4, GeH 4  Doppler Wind Experiment (2 USOs) (Atkinson talk yesterday)  Two probes, each with ASI and nephelometer (et al.)  Nephelometer (Simple? Polarization?)

TRS-25 PSDS Draft Report Saturn Entry Probe Science Objectives Tier 2 Objectives Tier 2 Objectives Vertical profile of zonal winds at the probe entry location Vertical profile of zonal winds at the probe entry location Location, density, and composition of clouds as a function of depth Location, density, and composition of clouds as a function of depth Variability of atmospheric structure and clouds in two locations Variability of atmospheric structure and clouds in two locations Vertical profile of water abundance at the probe entry location Vertical profile of water abundance at the probe entry location Precision isotope measurements for light elements in simple molecules Precision isotope measurements for light elements in simple molecules Elements such as N, O, & S Elements such as N, O, & S Omits measurements of diagnostic species such as CO, PH 3, AsH 3, SiH 4, GeH 4  Doppler Wind Experiment (2 USOs) (Atkinson talk yesterday)  Deep probe, penetrating to bar level, with NMS or TLS  Two probes, each with ASI and nephelometer (et al.)  Nephelometer (Simple? Polarization?)

TRS-26 PSDS Draft Report Saturn Entry Probe Science Objectives Tier 2 Objectives Tier 2 Objectives Vertical profile of zonal winds at the probe entry location Vertical profile of zonal winds at the probe entry location Location, density, and composition of clouds as a function of depth Location, density, and composition of clouds as a function of depth Variability of atmospheric structure and clouds in two locations Variability of atmospheric structure and clouds in two locations Vertical profile of water abundance at the probe entry location Vertical profile of water abundance at the probe entry location Precision isotope measurements for light elements in simple molecules Precision isotope measurements for light elements in simple molecules Elements such as N, O, & S Elements such as N, O, & S Omits measurements of diagnostic species such as CO, PH 3, AsH 3, SiH 4, GeH 4  Doppler Wind Experiment (2 USOs) (Atkinson talk yesterday)  Deep probe, penetrating to bar level, with NMS or TLS  Two probes, each with ASI and nephelometer (et al.)  Nephelometer (Simple? Polarization?)  Carefully designed TLS or very high-performance NMS

TRS-27 Uranus Entry Probe Science Objectives and Instrumentation Options “Medium Priority Science Objectives” “Medium Priority Science Objectives” Determine the noble gas abundances and isotopic ratios of H, C, N, and O Determine the noble gas abundances and isotopic ratios of H, C, N, and O Measure atmospheric structure at the probe descent location Measure atmospheric structure at the probe descent location (and their isotopes!)

TRS-28 Uranus Entry Probe Science Objectives and Instrumentation Options “Medium Priority Science Objectives” “Medium Priority Science Objectives” Determine the noble gas abundances and isotopic ratios of H, C, N, and O Determine the noble gas abundances and isotopic ratios of H, C, N, and O Measure atmospheric structure at the probe descent location Measure atmospheric structure at the probe descent location  Neutral Mass Spectrometer (NMS) Wide, continuous mass range Low to medium mass resolution  Tunable Laser Spectrometer (TLS) Small number of predetermined species Very high mass resolution (and their isotopes!)

TRS-29 Uranus Entry Probe Science Objectives and Instrumentation Options “Medium Priority Science Objectives” “Medium Priority Science Objectives” Determine the noble gas abundances and isotopic ratios of H, C, N, and O Determine the noble gas abundances and isotopic ratios of H, C, N, and O Measure atmospheric structure at the probe descent location Measure atmospheric structure at the probe descent location  Neutral Mass Spectrometer (NMS) Wide, continuous mass range Low to medium mass resolution  Tunable Laser Spectrometer (TLS) Small number of predetermined species Very high mass resolution  Atmospheric Structure Instrument (ASI) package System of thermometers, barometers, & accelerometers Very lightweight, low power, low data volume (and their isotopes!)

TRS-30 Uranus Entry Probe Science Objectives and Instrumentation Options “Lower Priority Science Objectives” “Lower Priority Science Objectives” Determine the vertical profile of zonal winds Determine the vertical profile of zonal winds Determine the presence of clouds as a function of depth in the atmosphere Determine the presence of clouds as a function of depth in the atmosphere Omits measurements of diagnostic species such as CO, PH 3, AsH 3, SiH 4, GeH 4

TRS-31 Uranus Entry Probe Science Objectives and Instrumentation Options “Lower Priority Science Objectives” “Lower Priority Science Objectives” Determine the vertical profile of zonal winds Determine the vertical profile of zonal winds Determine the presence of clouds as a function of depth in the atmosphere Determine the presence of clouds as a function of depth in the atmosphere Omits measurements of diagnostic species such as CO, PH 3, AsH 3, SiH 4, GeH 4  Doppler Wind Experiment (2 USOs) (Atkinson talk yesterday)

TRS-32 Uranus Entry Probe Science Objectives and Instrumentation Options “Lower Priority Science Objectives” “Lower Priority Science Objectives” Determine the vertical profile of zonal winds Determine the vertical profile of zonal winds Determine the presence of clouds as a function of depth in the atmosphere Determine the presence of clouds as a function of depth in the atmosphere Omits measurements of diagnostic species such as CO, PH 3, AsH 3, SiH 4, GeH 4  Doppler Wind Experiment (2 USOs) (Atkinson talk yesterday)  Nephelometer (Simple? Polarization?)

TRS-33 Venus Entry Probe Science Objectives and Instrumentation Options Science Objectives Science Objectives Understand the physics and chemistry of Venus’s atmosphere, “especially the abundances of trace gases, sulfur, light stable isotopes, and noble gas isotopes” Understand the physics and chemistry of Venus’s atmosphere, “especially the abundances of trace gases, sulfur, light stable isotopes, and noble gas isotopes” Understand the properties of Venus’s atmosphere down to the surface and improve our understanding of Venus’s zonal cloud-level winds Understand the properties of Venus’s atmosphere down to the surface and improve our understanding of Venus’s zonal cloud-level winds Constrain the coupling of thermochemical, photochemical, and dynamical processes in the atmosphere and between the atmosphere and the surface Constrain the coupling of thermochemical, photochemical, and dynamical processes in the atmosphere and between the atmosphere and the surface Look for planetary-scale evidence of past hydrologic cycles, oceans, and life and for constraints on the evolution of Venus’s atmosphere Look for planetary-scale evidence of past hydrologic cycles, oceans, and life and for constraints on the evolution of Venus’s atmosphere VISE

TRS-34 Venus Entry Probe Science Objectives and Instrumentation Options Measurements Measurements Composition Composition Atmospheric structure Atmospheric structure Winds, dynamics Winds, dynamics VISE  NMS and/or TLS  Doppler Wind Experiment (2 USOs)  ASI BUT... these instruments will encounter a harsher environment than those on 10-bar-level probes at Saturn or Uranus

TRS-35 Venus Entry Probe Science Objectives and Instrumentation Options Science Objectives Science Objectives Characterize the strong CO 2 greenhouse atmosphere Characterize the strong CO 2 greenhouse atmosphere Characterize the nature and variability of Venus’s superrotating atmospheric dynamics Characterize the nature and variability of Venus’s superrotating atmospheric dynamics Constrain surface/atmosphere chemical exchange in the lower atmosphere Constrain surface/atmosphere chemical exchange in the lower atmosphere Determine the origin of Venus’s atmosphere Determine the origin of Venus’s atmosphere Search for atmospheric evidence of recent climate change Search for atmospheric evidence of recent climate change VCM

TRS-36 Venus Entry Probe Science Objectives and Instrumentation Options Measurements Measurements Composition Composition Atmospheric structure Atmospheric structure Winds, dynamics Winds, dynamics Cloud properties Cloud properties VCM  NMS or TLS  Doppler Wind Experiment (2 USOs)  ASI Again, a harsher environment than for 10-bar-level probes at Saturn or Uranus  Capable nephelometer

TRS-37 Results of PSDS Recommendations? We’ll see what NASA’s response to the PSDS is! We’ll see what the Mid-Term Review (2016? 2017?) brings!

TRS-38 Questions?