Per my discussions with Tony Roman, I have expanded the timing limits on Visit 35 with the hopes that this will increase the number of guide stars available. I also revised the constraints to better position Mab during the visit. The set of OLG constraints on the Uranian moons is rather complicated but I believe the visit to be schedulable; I can relax some of those constraints if issues arise. ----- Submission 1 (Fri May 13 04:48:49 GMT 2005) ----- Error connecting to STScI submission server: java.rmi.ConnectIOException: Exception creating connection to: clotho.stsci.edu; nested exception is: java.net.NoRouteToHostException: No route to host ----- Submission 2 (Wed Apr 19 16:02:00 GMT 2006) ----- ----- Submission 1 (Fri Jan 24 15:57:06 PST 2003) ----- Assigned ID: 1135 Successfully submitted: Fri Jan 24 15:59:32 PST 2003 Rings of Uranus: Dynamics, Particle Properties and Shepherding Moons We propose to image the rings and small inner satellites of Uranus using the High Resolution Channel of the ACS. The revolutionary capabilities of the ACS will allow us to address a variety of important questions relating to ring properties and ring-moon interactions. Observations at a range of wavelengths and phase angles will reveal the opposition surges of these rings and moons, providing information on color and surface structure. Measurements of the ring in front of the planet will provide complementary information on optical depth; any variations of optical depth with wavelength will reveal the rings' poorly-constrained population of embedded dust. The rings of Uranus are closing rapidly as the planet approaches equinox in 2007, an event that takes place only every 42 years. Using this opportunity, our observations will be repeated at different solar and terrestrial tilt angles; this sequence of images will be particularly valuable for constraining the physical thickness and packing density of the rings. We will place particular emphasis on the rotational variations of the Epsilon Ring, whose radial width (and therefore its packing density) varies by a factor of five. In addition, deep exposures through the CLEAR filter will enable us to detect and recover 4-5 km moons in or near the ring system. Dynamicists invoke numerous such moons to "shepherd" the many sharp ring boundaries, so this will serve as a definitive test of the theory.
Images will be centered on the planet and oriented such that the rings extend along the HRC's x-axis. In overexposed images of the planet, the saturated pixels bloom along the y-axis so this orientation guarantees that they do not corrupt our observations. Uranus is oriented on the sky such that this requirement is generally easy to meet. Each visit will contain a set of saturated exposures (CLEAR at ~250 sec; F606W at ~100 sec; F475W at ~150 sec) for optimal ring photometry and to continue our search for small satellites. We will also obtain unsaturated exposures (F303W at ~200 sec; F475W at 15 sec; F606W at 10 sec; F814w at ~70 sec) for expanded wavelength coverage and to support planet science. Most ring photometry images are embedded in a dither pattern involving a 2.5-pixel shift along the x-axis; this is used to improve the resolution on individual rings. Single-orbit visits occur at phase angles of 1.2, 0.5, 0.2 degrees prior to opposition (September 1, 2005) and at 2.8 degrees after solar conjunction (June 2006). A three-orbit visit as close as possible to opposition will include many additional long, CLEAR exposures to search more completely for small orbiting moons. (1) We understand that ORIENT constraints are discouraged under HST's 2-gyro operation but they are critical for us to achieve our science goals. (2) OLG constraints on the brightest moons are needed to ensure that their bright diffraction spikes do not cross the ring region. We have confirmed that these constraints leave multiple scheduling options for each visit, with most options lasting at least several hours. (3) Visits 31, 32 and 33 are constrained by our wish to catch a particular orbiting feature near its maximum elongation from the planet; opportunities repeat every 3 hours 46 minutes but the start time of a visit has a brief window of only 44 minutes. In case any of these are too difficult to schedule, we also provide alternative visits 3A, 3B, 3C which do not have the strict timing constraints. These are designated ON HOLD. We therefore request one visit from each pair (31,3A), (32,3B) and (33,3C), where the former is preferred but the latter is acceptable. (4) If at all possible, schedule our opposition visit 34 as three consecutive orbits; this maximizes the orbital coverage for our search for small moons. SOLAR SYSTEM 12 false 0.0 false false false false false AVAILABLE SOLAR SYSTEM Ariel, Umbriel, Titania and Oberon are required to be more than 88,000 km from the center of Uranus in projected distance along the ring ansa. This guarantees that any vertical diffraction spike falls beyond the orbit of Puck. PLANET Uranus STD=URANUS NOT OLG OF ARIEL BETWEEN 0.0 27.4, NOT OLG OF ARIEL BETWEEN 155.3 204.7, NOT OLG OF ARIEL BETWEEN 335.3 360.0, NOT OLG OF UMBRIEL BETWEEN 0.0 19.4, NOT OLG OF UMBRIEL BETWEEN 160.6 199.4, NOT OLG OF UMBRIEL BETWEEN 340.6 360.0, NOT OLG OF TITANIA BETWEEN 0.0 11.7, NOT OLG OF TITANIA BETWEEN 168.3 191.7, NOT OLG OF TITANIA BETWEEN 348.3 360.0, NOT OLG OF OBERON BETWEEN 0.0 8.7, NOT OLG OF OBERON BETWEEN 171.3 188.7, NOT OLG OF OBERON BETWEEN 351.3 360.0 SOLAR SYSTEM Uranus with Mab within 40 degrees of maximum elongation. Ariel, Umbriel, Titania and Oberon are required to be more than 100,000 km from the center of Uranus in projected distance along the ring ansa; this guarantees that any bright, vertical diffraction spike falls beyond the orbit of Mab. Also, Miranda's diffraction spike must stay outside the ring system and at least 1 arcsec from Mab. PLANET Uranus STD=URANUS NOT OLG OF ARIEL BETWEEN 0.0 31.5, NOT OLG OF ARIEL BETWEEN 148.5 211.5, NOT OLG OF ARIEL BETWEEN 328.5 360.0, NOT OLG OF UMBRIEL BETWEEN 0.0 22.1, NOT OLG OF UMBRIEL BETWEEN 157.9 202.1, NOT OLG OF UMBRIEL BETWEEN 337.9 360.0, NOT OLG OF TITANIA BETWEEN 0.0 13.3, NOT OLG OF TITANIA BETWEEN 166.7 193.3, NOT OLG OF TITANIA BETWEEN 346.7 360.0, NOT OLG OF OBERON BETWEEN 0.0 9.9, NOT OLG OF OBERON BETWEEN 170.1 189.9, NOT OLG OF OBERON BETWEEN 350.1 360.0, NOT OLG OF MAB BETWEEN 0.0 50.0, NOT OLG OF MAB BETWEEN 130.0 230.0, NOT OLG OF MAB BETWEEN 310.0 360.0, NOT OLG OF MIRANDA BETWEEN 0.0 25.0, NOT OLG OF MIRANDA BETWEEN 155.0 205.0, NOT OLG OF MIRANDA BETWEEN 335.0 360.0, SEP OF MIRANDA MAB FROM EARTH GT 1.0" ACS/HRC Imaging No No F330W CLEAR1S ACS/HRC Imaging No No F435W CLEAR1S ACS/HRC Imaging No No F475W CLEAR2S ACS/HRC Imaging No No F555W CLEAR2S ACS/HRC Imaging No No F625W CLEAR2S ACS/HRC Imaging No No F775W CLEAR2S ACS/HRC Imaging No No F814W CLEAR1S ACS/HRC Imaging No No F892N CLEAR2S ACS/HRC Imaging No No F606W CLEAR2S POS-TARG DITHER 0.07105 This is a single horizontal shift along the HRC pixel grid of 2.5 pixels. It should enable finer radial resolution along the ring ansa, which is also aligned with the pixel grid. LINE false false 2 5.8 LINE 1 false /private/tmp/OPVisit43395.xml Uranian rings with phase angle near 1.2 degrees. Rings oriented parallel to the HRC x-axis. Schedule either visit 31 or 3A. Visit 31 is strongly preferred but has strict timing constraints defined by the requirement to capture a particular orbiting target. Use Visit 3A instead if Visit 31 is too difficult to schedule. (Tic-Visit :proposal-id 10473 :visit-id "31" :proposal-version -1 :trans-version "20060322" :date "19-Apr-2006 07:26:14.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 220816 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10473 :visit-id "31" :obset-id "31" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10473 :visit-id "31" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 280 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3028 :pcs-gap 0 ) true 1 0 /private/tmp/OPVisit43396.xml Uranian rings with phase angle near 1.2 degrees. Rings oriented parallel to the HRC x-axis. Schedule either visit 31 or 3A. Visit 31 is strongly preferred but has strict timing constraints defined by the requirement to capture a particular orbiting target. Use Visit 3A instead if Visit 31 is too difficult to schedule. (Tic-Visit :proposal-id 10473 :visit-id "3A" :proposal-version -1 :trans-version "20060322" :date "19-Apr-2006 07:26:32.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 220816 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10473 :visit-id "3A" :obset-id "3A" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10473 :visit-id "3A" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 280 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3028 :pcs-gap 0 ) true 1 0 Use in place of Visit 31 if Visit 31 is too difficult to schedule. /private/tmp/OPVisit43397.xml Uranian rings with phase angle near 0.5 degrees. Rings oriented parallel to the HRC x-axis. Schedule either visit 32 or 3B. Visit 32 is strongly preferred but has strict timing constraints defined by the requirement to capture a particular orbiting target. Use Visit 3B instead if Visit 32 is too difficult to schedule. (Tic-Visit :proposal-id 10473 :visit-id "32" :proposal-version -1 :trans-version "20060322" :date "19-Apr-2006 07:26:49.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 220816 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10473 :visit-id "32" :obset-id "32" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10473 :visit-id "32" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 280 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3028 :pcs-gap 0 ) true 1 0 /private/tmp/OPVisit43398.xml Uranian rings with phase angle near 0.5 degrees. Rings oriented parallel to the HRC x-axis. Schedule either visit 32 or 3B. Visit 32 is strongly preferred but has strict timing constraints defined by the requirement to capture a particular orbiting target. Use Visit 3B instead if Visit 32 is too difficult to schedule. (Tic-Visit :proposal-id 10473 :visit-id "3B" :proposal-version -1 :trans-version "20060322" :date "19-Apr-2006 07:27:12.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 220816 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10473 :visit-id "3B" :obset-id "3B" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10473 :visit-id "3B" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 280 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3028 :pcs-gap 0 ) true 1 0 Use in place of Visit 32 if Visit 32 is too difficult to schedule. /private/tmp/OPVisit43399.xml Uranian rings with phase angle near 0.2 degrees. Rings oriented parallel to the HRC x-axis. Schedule either visit 33 or 3C. Visit 33 is strongly preferred but has strict timing constraints defined by the requirement to capture a particular orbiting target. Use Visit 3C instead if Visit 33 is too difficult to schedule. (Tic-Visit :proposal-id 10473 :visit-id "33" :proposal-version -1 :trans-version "20060322" :date "19-Apr-2006 07:27:27.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 220816 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10473 :visit-id "33" :obset-id "33" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10473 :visit-id "33" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 280 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3028 :pcs-gap 0 ) true 1 0 /private/tmp/OPVisit43400.xml Uranian rings with phase angle near 0.2 degrees. Rings oriented parallel to the HRC x-axis. Schedule either visit 33 or 3C. Visit 33 is strongly preferred but has strict timing constraints defined by the requirement to capture a particular orbiting target. Use Visit 3C instead if Visit 33 is too difficult to schedule. (Tic-Visit :proposal-id 10473 :visit-id "3C" :proposal-version -1 :trans-version "20060322" :date "19-Apr-2006 07:27:42.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 220816 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10473 :visit-id "3C" :obset-id "3C" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10473 :visit-id "3C" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2658 :al-overhead-at-end 0 :internal-dur-at-end 280 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3028 :pcs-gap 0 ) true 1 0 Use in place of Visit 33 if Visit 33 is too difficult to schedule. /private/tmp/OPVisit43401.xml Uranian rings with phase angle near or below 0.1 degrees. Rings oriented parallel to the HRC x-axis. Three consecutive orbits to search for small satellites. (Tic-Visit :proposal-id 10473 :visit-id "34" :proposal-version -1 :trans-version "20060322" :date "19-Apr-2006 07:28:10.0" :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 533648 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10473 :visit-id "34" :obset-id "34" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10473 :visit-id "34" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2657 :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 3028 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10473 :visit-id "34" :orbit-number 2 :pcs-time 355 :si-vis-utilization 2656 :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 3028 :pcs-gap 0 ) (Tic-Orbit :proposal-id 10473 :visit-id "34" :orbit-number 3 :pcs-time 355 :si-vis-utilization 2657 :al-overhead-at-end 0 :internal-dur-at-end 240 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3028 :pcs-gap 0 ) true 3 0 /Users/Mark/Work/General/Proposals/2005 HST-Uranus/Cycle 14 Phase II/10473-new.APT/OP-cache/10473-v35.xml Uranian rings after solar conjuction, with phase angle near maximum of 2.8 degrees. Rings open to Earth by only 2.9 degrees. Rings oriented parallel to the HRC x-axis. (Tic-Visit :proposal-id 10473 :visit-id "35" :proposal-version -1 :trans-version "20060322" :date "14-Apr-2006 18:33:00.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "27" :si-bright-earth-limb-angle 20.0 :data-volume 220816 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 10473 :visit-id "35" :obset-id "35" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 10473 :visit-id "35" :orbit-number 1 :pcs-time 355 :si-vis-utilization 2669 :al-overhead-at-end 0 :internal-dur-at-end 280 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3028 :pcs-gap 0 ) true 1 0 /private/tmp/OPVisit61478.xml