0 Assigned ID: 5006 ----- Attempting Submission 1 (Tue Mar 19 18:15:46 GMT 2024) ----- Illegal ACS Spectral Elements combination. Note some combinations are Cautionary Use Only Illegal ACS Spectral Elements combination. Note some combinations are Cautionary Use Only Illegal ACS Spectral Elements combination. Note some combinations are Cautionary Use Only Illegal ACS Spectral Elements combination. Note some combinations are Cautionary Use Only Illegal ACS Spectral Elements combination. Note some combinations are Cautionary Use Only Illegal ACS Spectral Elements combination. Note some combinations are Cautionary Use Only Illegal ACS Spectral Elements combination. Note some combinations are Cautionary Use Only Illegal ACS Spectral Elements combination. Note some combinations are Cautionary Use Only Illegal ACS Spectral Elements combination. Note some combinations are Cautionary Use Only Illegal ACS Spectral Elements combination. Note some combinations are Cautionary Use Only Illegal ACS Spectral Elements combination. Note some combinations are Cautionary Use Only Illegal ACS Spectral Elements combination. Note some combinations are Cautionary Use Only Available mode used has been approved -1417534040 ----- Attempting Submission 1 (Thu Jul 25 13:46:46 GMT 2024) ----- Email 7/24/24 "I discussed this [your request to use the mode] with Norman, and we both agree that use of the F435W+POLUV is allowed and that we approve your use of this combination for GO 17808. - Dean Hines - 24 July, 2024" Ice giant atmospheres, rings and moons - physics of the macroscopic to the microscopic Uranus is the highest priority destination for a future NASA flagship mission in the Origins, Worlds and Life planetary science decadal survey. With Neptune, these two are the solar system ice giant siblings, representative of a multitude of kindred exoplanets. We propose to obtain imaging polarimetry of Uranus and Neptune at unprecedented spatial resolution with ACS in order to advance our knowledge of the macroscopic and microphysical character of the scattering atmospheres of these two worlds. With HST resolution, we can separate polar hazes, storms and bands, revealing the global scattering properties in unprecedented detail while identifying for the first time the scattering properties of features impossible to determine from the ground. The polarization depends on the altitude of the scatterers, their chemical composition, and microscopic shape and size. Given the plethora of ice giant exoplanets, high quality empirical measurements and modeling of the polarization distribution of these local archetypes and their varied hydrocarbon hazes will facilitate extrapolation to one of the most commonly found exoplanet populations. We will also obtain polarization measurements of the rings of Uranus and moons of both Uranus and Neptune. This is particularly critical to the top priority Uranus Orbiter and Probe flagship mission, as further knowledge is needed to enable safe passage through the upper atmosphere and dusty ring environment. We propose to acquire nine images per orbit, three for each polarizer using three filters (F435W, F606W and F775W) selected to span the visible spectrum without significant filter-to-filter overlap, and three orbits per visit to accumulate the appropriate number of photons for both Neptune and Uranus, two visits each. Dr. William Sparks has extensive experience of HST instrumentation and was deputy head of the Instrument Division at STScI. As a member of the ACS Science Definition team, his primary responsibility was the implementation of the polarimetric capability. Now at the SETI Institute (STScI emeritus), he continues research on Solar System targets and instrumentation for polarimetry. He has led multiple HST polarimetric proposals, including a Cycle 30 proposal for imaging polarimetry of Europa which offers similar requirements to the ice giant planets. Dr. Kimberly Bott is an expert in polarized reflected light modelling with VSTAR, a model capable of computing the full Stokes radiative transfer of planetary atmospheres. She has used VSTAR previously to model terrestrial and gaseous worlds. She has experience with observations of solar system objects, polarimetric observations and instrumentation and participated in a benchmark study comparing VSTAR and DAP. Prof. Jeremy Bailey is a world-renowned expert in polarimetry, astrobiology and planetary and stellar atmospheric modelling. He designed and built HIPPI (Bailey, et al. 2015), the world's most sensitive stellar polarimeter. He has authored 270+ scientific papers including a seminal paper using polarimetry to reveal the handedness of molecules in star forming regions and the implications for life (Bailey et al. 1998). He will contribute his expert knowledge to the data acquisition, processing and interpretation. Dr. Ludmilla Kolokolova is Principal Research Scientist at the Small Bodies group, University of Maryland. She is an expert in light scattering by surfaces and dust particles. Her principal experience is in the computer modeling of photometric and polarimetric characteristics of the solar system objects with a focus on comets and satellites of giant planets, which are required for the interpretation of the observations, particularly the rings of Uranus. Dr. John Grunsfeld is an astrophysicist and a former NASA astronaut. He is a veteran of five Space Shuttle flights and has served as NASA Chief Scientist and Associate Administrator for Science. He is strongly committed to furthering exploration of the outer solar system. He also developed and implemented on-orbit the EVA fix for the failed power supply on ACS, and previously led the mission that installed ACS. Louis (Eddie) Bergeron is a highly skilled member of the STScI technical staff, with exceptional knowledge of the HST systems including scheduling and tracking. He has previously worked with the P.I. in both technical and scientific capacity, on polarimetry analysis from NICMOS and the VLT/FORS, and observations aimed at seeking evidence of plumes on Europa. His technical expertise is essential for data processing. Dr. Daniel Cotton is a Research Astronomer specializing in precision polarimetry and radiative transfer modelling of planets. He contributed to the development of the world's most precise optical astronomical polarimeters (HIPPI-2), and was responsible for the development of its reduction software. He will contribute his expert knowledge to data processing and interpretation. Prof. Eileen Meyer is a multi-wavelength observational astronomer with a career-long history of using many of the major national and international observatories including HST. Dr. Meyer's primary area of expertise is high-energy extragalactic phenomena but she also has experience with imaging polarimetry on HST, and has recently included solar system observations in her portfolio. She is P.I. for the ongoing UMBC observatory renovation project and leads the AstroPol group at UMBC, where, with P.I. Sparks, she oversaw the construction of a clone of co-I Bailey's PICSARR polarimeter. Solar system observations figure prominently in that project. Dr. Simon has been studying giant planet atmospheres for over 25 years, primarily using Hubble data. She is the P.I. of the Outer Planet Atmospheres Legacy program, and those data will be used to support this program by expanding the wavelength coverage and providing a time-evolution context. She also served as a co-lead on multiple Uranus and Neptune mission studies in support of the last two decadal surveys. Solar System Astronomy 6 false false false false false false false false AVAILABLE SOLAR SYSTEM PLANET planet STD=URANUS EARTH SOLAR SYSTEM PLANET planet STD=NEPTUNE NOT ECL P PARTIAL OF NEPTUNE BY TRITON FROM EARTH EARTH ACS/WFC Imaging No Yes F435W ACS/WFC Imaging No Yes F606W ACS/WFC Imaging No Yes F775W ACS/WFC Imaging No Yes F435W ACS/WFC Imaging No Yes F606W ACS/WFC Imaging No Yes F775W POS-TARG DITHER 0.17 LINE false false 3 47.23 ACS-WFC-DITHER-LINE 1 false POS-TARG DITHER 0.149 LINE false false 2 34.25 ACS-WFC-DITHER-LINE 2 false /private/var/folders/8t/mg1bkfyj20xf2vfc_9vyhfs80006z1/T/OPVisit2558629801622072172.xml The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. 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CASM was run in Phase II mode. (Tic-Visit :proposal-id 17808 :visit-id "02" :proposal-version -1 :trans-version "20240627" :date "25-Jul-2024 10:00:57.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1705840 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17808 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17808 :visit-id "02" :orbit-number 1 :pcs-time 380 :si-vis-utilization 1948 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2645 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17808 :visit-id "02" :orbit-number 2 :pcs-time 380 :si-vis-utilization 1937 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2645 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17808 :visit-id "02" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2064 :al-overhead-at-end 0 :internal-dur-at-end 192 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2645 :pcs-gap 0 ) true 3 0 /private/var/folders/8t/mg1bkfyj20xf2vfc_9vyhfs80006z1/T/OPVisit11747436932884293365.xml The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17808 :visit-id "03" :proposal-version -1 :trans-version "20240627" :date "25-Jul-2024 10:01:00.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1705840 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17808 :visit-id "03" :obset-id "03" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17808 :visit-id "03" :orbit-number 1 :pcs-time 380 :si-vis-utilization 1969 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2645 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17808 :visit-id "03" :orbit-number 2 :pcs-time 380 :si-vis-utilization 1975 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2645 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17808 :visit-id "03" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2122 :al-overhead-at-end 0 :internal-dur-at-end 192 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2645 :pcs-gap 0 ) true 3 0 /private/var/folders/8t/mg1bkfyj20xf2vfc_9vyhfs80006z1/T/OPVisit4923966543126181533.xml The scheduling data was generated by CASM 32.1.3. CASM was run in Phase II mode. (Tic-Visit :proposal-id 17808 :visit-id "04" :proposal-version -1 :trans-version "20240627" :date "25-Jul-2024 10:01:02.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 3 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 1705840 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 17808 :visit-id "04" :obset-id "04" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 17808 :visit-id "04" :orbit-number 1 :pcs-time 380 :si-vis-utilization 1969 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2645 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17808 :visit-id "04" :orbit-number 2 :pcs-time 380 :si-vis-utilization 1975 :al-overhead-at-end 0 :internal-dur-at-end 0 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2645 :pcs-gap 0 ) (Tic-Orbit :proposal-id 17808 :visit-id "04" :orbit-number 3 :pcs-time 380 :si-vis-utilization 2122 :al-overhead-at-end 0 :internal-dur-at-end 192 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 2645 :pcs-gap 0 ) true 3 0