New Horizons Mission Planning Support: A Deep Search for Faint Rings of Pluto

New Horizons Mission Planning Support: A Deep Search for Faint Rings of Pluto With the discoveries of Hydra and Nix, dwarf planet Pluto centers a more extensive satellite system than any terrestrial planet. Small moons are usually accompanied by rings of faint dust, which arise from impacts into their surfaces. Such rings show interesting dynamics including the influence of non-gravitational forces such as radiation pressure and Poynting-Robertson drag. A previous search for rings of Pluto in HST images was negative, but was limited by the scattered light from Pluto and Charon. Our more optimized plan will enable us to model and subtract out the scattered light pattern, yielding a detection threshold 10-30 times fainter than the prior limit. If Pluto sports a ring comparable to the major dust rings of the giant planets, our observing plan should detect it. This work supports the New Horizons mission by potentially revealing a dust hazard that might endanger the spacecraft during its 2015 flyby. It could also enhance the science return by allowing planners to target a known feature rather than conducting a more resource-intensive general search for rings. We request Director's Discretionary time because the Pluto observing sequence will be finalized in 2011; thus the observing window in June represents our last chance to obtain results that could influence the mission.

We propose two 2-orbit visits. Pairs of visits are defined such that ORIENT changes by 90 degrees but Pluto and Charon fall at roughly the same locations on the CCD. This will rotate Pluto's hypothetical dust rings but leave the pattern of scattered light around Pluto and Charon nearly unchanged. We orient that dust rings horizontally on the CCD in one visit and vertically in the other; these orientations maximize the separation between the rings and the diagonal diffraction spikes. We position Charon atop a spike to keep its diffraction pattern away from the rings as well. The horizontal ring orientation requires ORIENT ~ 192 degrees and can only be scheduled in June 2011. The vertical orientation can be scheduled either before (ORIENT ~ 282) or after (ORIENT ~ 102). This provides eight possible pairs of visits, depending on the vertical ORIENT and the four possible diagonal offsets of Charon relative to Pluto. All eight options are specified in this Phase II proposal as pairs of Visits 01/02, 11/12, ... 71/72. Seven visit pairs are identified as ON HOLD but all pairs are scientifically equivalent. No dithering will be performed, because the stability of the pointing and stability of the scattered light pattern are paramount. Our target, if detected, will encompass many pixels, so hot pixels will not obscure it and can be rejected (along with background stars and cosmic ray hits) based on statistical tests. Each visit will consist of ten long (479 s) exposures through the broadest filter, F606W. This enables us to obtain substantial integration time while limiting the effects of cosmic ray hits in individual frames. The second orbit of each visit includes two brief, un-saturated exposures at the end through F606W and F475W. The un-saturated images will provide reliable position measurements for Pluto and Charon, to be used for geometric reference. These exposures will also enable us to check our overall calibration against prior Pluto images taken with the ACS. This modified submission includes an additional follow-up visit to our recently executed program, to confirm the existence of a small moon of Pluto. We will execute five long exposures through broad filter F606W. A small POS TARG step in the middle will reduce the chance of the detection being lost due to a hot pixel. The plan can be scheduled at any time that Pluto is observable by HST, but ORIENT constraints vary by date to keep the diffraction spikes of Pluto and Charon away from our projected location for the moon. This is handled by providing 7 alternative visits A2-A8, each with a different ORIENT constraint. Six are designated "ON HOLD". All are scientifically equivalent, although projecting the location of the moon becomes less precise as time passes. SOLAR SYSTEM 0 false 0.0 0.0 false false false false SUPPORTED SOLAR SYSTEM Because the sub-Earth latitude of Pluto is ~ 44 degrees, the OLG of Charon needs to be 35, 145, 215 or 325 to place it along a diagonal from Pluto, assuming Pluto is oriented with its pole parallel or perpendicular to the UVIS Y-axis. PLANET Pluto with Charon along a 45 degree diagonal in the first orbital quadrant. STD=PLUTO OLG OF CHARON BETWEEN 20 50 EARTH SOLAR SYSTEM Because the sub-Earth latitude of Pluto is ~ 44 degrees, the OLG of Charon needs to be 35, 145, 215 or 325 to place it along a diagonal from Pluto, assuming Pluto is oriented with its pole parallel or perpendicular to the UVIS Y-axis. PLANET Pluto with Charon along a 45 degree diagonal in its second orbital quadrant. STD=PLUTO OLG OF CHARON BETWEEN 130 160 EARTH SOLAR SYSTEM Because the sub-Earth latitude of Pluto is ~ 44 degrees, the OLG of Charon needs to be 35, 145, 215 or 325 to place it along a diagonal from Pluto, assuming Pluto is oriented with its pole parallel or perpendicular to the UVIS Y-axis. PLANET Pluto with Charon along a 45 degree diagonal in the third orbital quadrant. STD=PLUTO OLG OF CHARON BETWEEN 200 230 EARTH SOLAR SYSTEM Because the sub-Earth latitude of Pluto is ~ 44 degrees, the OLG of Charon needs to be 35, 145, 215 or 325 to place it along a diagonal from Pluto, assuming Pluto is oriented with its pole parallel or perpendicular to the UVIS Y-axis. PLANET Pluto with Charon along a 45 degree diagonal in the fourth orbital quadrant. STD=PLUTO OLG OF CHARON BETWEEN 310 340 EARTH SOLAR SYSTEM PLANET Pluto STD=PLUTO EARTH WFC3/UVIS Imaging No No F606W WFC3/UVIS Imaging No No F475W Using ephemeris for target 12436-01-PLUTO-CHARON-3RD-QUADRANT ephemeris data for target 12436-01-PLUTO-CHARON-3RD-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([02 After 01 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole oriented downward, parallel to the UVIS Y-axis; Charon on the diagonal at upper left (3rd orbital quadrant). To be scheduled along with Visit 02. (Tic-Visit :proposal-id 12436 :visit-id "01" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:53:58.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "01" :obset-id "01" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "01" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "01" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Using ephemeris for target 12436-02-PLUTO-CHARON-2ND-QUADRANT ephemeris data for target 12436-02-PLUTO-CHARON-2ND-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([02 After 01 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole pointed rightward, perpendicular to the UVIS Y-axis; Charon on the diagonal at upper left (2nd orbital quadrant). To be scheduled along with Visit 01. (Tic-Visit :proposal-id 12436 :visit-id "02" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:04.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "02" :obset-id "02" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "02" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "02" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Using ephemeris for target 12436-11-PLUTO-CHARON-4TH-QUADRANT ephemeris data for target 12436-11-PLUTO-CHARON-4TH-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([12 After 11 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole pointed leftward, perpendicular to the UVIS Y-axis; Charon on the diagonal at upper left (4th orbital quadrant). To be scheduled along with Visit 12. (Tic-Visit :proposal-id 12436 :visit-id "11" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:08.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "11" :obset-id "11" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "11" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "11" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 11/12 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-12-PLUTO-CHARON-3RD-QUADRANT ephemeris data for target 12436-12-PLUTO-CHARON-3RD-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([12 After 11 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole oriented downward, parallel to the UVIS Y-axis; Charon on the diagonal at upper left (3rd orbital quadrant). To be scheduled along with Visit 11. (Tic-Visit :proposal-id 12436 :visit-id "12" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:10.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "12" :obset-id "12" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "12" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "12" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 11/12 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-21-PLUTO-CHARON-4TH-QUADRANT ephemeris data for target 12436-21-PLUTO-CHARON-4TH-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([22 After 21 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole oriented downward, parallel to the UVIS Y-axis; Charon on the diagonal at lower left (4th orbital quadrant). To be scheduled along with Visit 22. 1309270443000 187.99999999999994 (Tic-Visit :proposal-id 12436 :visit-id "21" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:12.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "21" :obset-id "21" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "21" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "21" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 21/22 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-22-PLUTO-CHARON-3RD-QUADRANT ephemeris data for target 12436-22-PLUTO-CHARON-3RD-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([22 After 21 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole pointed rightward, perpendicular to the UVIS Y-axis; Charon on the diagonal at lower left (3rd orbital quadrant). To be scheduled along with Visit 21. 1309684426000 106.0 (Tic-Visit :proposal-id 12436 :visit-id "22" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:13.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "22" :obset-id "22" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "22" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "22" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 21/22 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-31-PLUTO-CHARON-1ST-QUADRANT ephemeris data for target 12436-31-PLUTO-CHARON-1ST-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([32 After 31 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole pointed leftward, perpendicular to the UVIS Y-axis; Charon on the diagonal at lower left (1st orbital quadrant). To be scheduled along with Visit 32. (Tic-Visit :proposal-id 12436 :visit-id "31" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:15.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "31" :obset-id "31" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "31" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "31" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 31/32 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-32-PLUTO-CHARON-4TH-QUADRANT ephemeris data for target 12436-32-PLUTO-CHARON-4TH-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([32 After 31 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole oriented downward, parallel to the UVIS Y-axis; Charon on the diagonal at lower left (4th orbital quadrant). To be scheduled along with Visit 31. (Tic-Visit :proposal-id 12436 :visit-id "32" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:17.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "32" :obset-id "32" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "32" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "32" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 31/32 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-41-PLUTO-CHARON-1ST-QUADRANT ephemeris data for target 12436-41-PLUTO-CHARON-1ST-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([42 After 41 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole oriented downward, parallel to the UVIS Y-axis; Charon on the diagonal at lower right (1st orbital quadrant). To be scheduled along with Visit 42. (Tic-Visit :proposal-id 12436 :visit-id "41" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:19.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "41" :obset-id "41" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "41" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "41" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 41/42 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-42-PLUTO-CHARON-4TH-QUADRANT ephemeris data for target 12436-42-PLUTO-CHARON-4TH-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([42 After 41 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole pointed rightward, perpendicular to the UVIS Y-axis; Charon on the diagonal at lower right (4th orbital quadrant). To be scheduled along with Visit 41. (Tic-Visit :proposal-id 12436 :visit-id "42" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:22.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "42" :obset-id "42" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "42" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "42" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 41/42 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-51-PLUTO-CHARON-2ND-QUADRANT ephemeris data for target 12436-51-PLUTO-CHARON-2ND-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([52 After 51 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole pointed leftward, perpendicular to the UVIS Y-axis; Charon on the diagonal at lower right (2nd orbital quadrant). To be scheduled along with Visit 52. (Tic-Visit :proposal-id 12436 :visit-id "51" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:24.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "51" :obset-id "51" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "51" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "51" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 51/52 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-52-PLUTO-CHARON-1ST-QUADRANT ephemeris data for target 12436-52-PLUTO-CHARON-1ST-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([52 After 51 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole oriented downward, parallel to the UVIS Y-axis; Charon on the diagonal at lower right (1st orbital quadrant). To be scheduled along with Visit 51. (Tic-Visit :proposal-id 12436 :visit-id "52" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:27.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "52" :obset-id "52" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "52" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "52" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 51/52 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-61-PLUTO-CHARON-2ND-QUADRANT ephemeris data for target 12436-61-PLUTO-CHARON-2ND-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([62 After 61 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole oriented downward, parallel to the UVIS Y-axis; Charon on the diagonal at upper right (2nd orbital quadrant). To be scheduled along with Visit 62. (Tic-Visit :proposal-id 12436 :visit-id "61" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:29.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "61" :obset-id "61" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "61" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "61" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 61/62 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-62-PLUTO-CHARON-1ST-QUADRANT ephemeris data for target 12436-62-PLUTO-CHARON-1ST-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([62 After 61 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole pointed rightward, perpendicular to the UVIS Y-axis; Charon on the diagonal at upper right (1st orbital quadrant). To be scheduled along with Visit 61. (Tic-Visit :proposal-id 12436 :visit-id "62" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:31.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "62" :obset-id "62" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "62" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "62" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 61/62 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-71-PLUTO-CHARON-3RD-QUADRANT ephemeris data for target 12436-71-PLUTO-CHARON-3RD-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([72 After 71 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole pointed leftward, perpendicular to the UVIS Y-axis; Charon on the diagonal at upper right (3rd orbital quadrant). To be scheduled along with Visit 72. (Tic-Visit :proposal-id 12436 :visit-id "71" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:34.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "71" :obset-id "71" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "71" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "71" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 71/72 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-72-PLUTO-CHARON-2ND-QUADRANT ephemeris data for target 12436-72-PLUTO-CHARON-2ND-QUADRANT does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 Timing link suitability includes constraints ([72 After 71 by at most 40.0 days]) The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. Pluto with its prograde rotation pole oriented downward, parallel to the UVIS Y-axis; Charon on the diagonal at upper right (2nd orbital quadrant). To be scheduled along with Visit 71. (Tic-Visit :proposal-id 12436 :visit-id "72" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:37.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 2 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 54928 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "72" :obset-id "72" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "72" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2686 :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 3021 :pcs-gap 0 ) (Tic-Orbit :proposal-id 12436 :visit-id "72" :orbit-number 2 :pcs-time 222 :si-vis-utilization 2779 :al-overhead-at-end 0 :internal-dur-at-end 99 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 2 0 Visits 71/72 are a scientifically equivalent alternative to Visits 01/02. See comment field for Visit 01 for more information. Using ephemeris for target 12436-A2-PLUTO ephemeris data for target 12436-A2-PLUTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. A follow-up visit of one orbit to confirm the existence of a small moon of Pluto. ORIENT = 82 selected to keep the moon clear of diffraction spikes. Available roughly July 10-12, 2011. (Tic-Visit :proposal-id 12436 :visit-id "A2" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:39.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 22896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "A2" :obset-id "A2" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "A2" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2876 :al-overhead-at-end 0 :internal-dur-at-end 64 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) true 1 0 Using ephemeris for target 12436-A3-PLUTO ephemeris data for target 12436-A3-PLUTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. A follow-up visit of one orbit to confirm the existence of a small moon of Pluto. ORIENT = 102 selected to keep the moon clear of diffraction spikes. Available roughly July 13-15, 2011. (Tic-Visit :proposal-id 12436 :visit-id "A3" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:40.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 22896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "A3" :obset-id "A3" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "A3" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2876 :al-overhead-at-end 0 :internal-dur-at-end 64 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) true 1 0 One of 7 alternative visit options. Schedule one. ORIENT constraints vary by date to keep the diffraction spikes of Pluto and Charon away from the moon. Using ephemeris for target 12436-A4-PLUTO ephemeris data for target 12436-A4-PLUTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. A follow-up visit of one orbit to confirm the existence of a small moon of Pluto. ORIENT = 108 selected to keep the moon clear of diffraction spikes and saturation bloom from Charon. Available roughly July 16-19, 2011. 1311024324000 108.0 (Tic-Visit :proposal-id 12436 :visit-id "A4" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:41.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 22896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "A4" :obset-id "A4" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "A4" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2876 :al-overhead-at-end 0 :internal-dur-at-end 64 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3234 :pcs-gap 0 ) false 1 0 One of 7 alternative visit options. Schedule one. ORIENT constraints vary by date to keep the diffraction spikes of Pluto and Charon away from the moon. Using ephemeris for target 12436-A5-PLUTO ephemeris data for target 12436-A5-PLUTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. A follow-up visit of one orbit to confirm the existence of a small moon of Pluto. ORIENT = 71 selected to keep the moon clear of diffraction spikes. Available roughly July 20-21, 2011. (Tic-Visit :proposal-id 12436 :visit-id "A5" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:42.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 22896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "A5" :obset-id "A5" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "A5" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2676 :al-overhead-at-end 0 :internal-dur-at-end 64 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 1 0 One of 7 alternative visit options. Schedule one. ORIENT constraints vary by date to keep the diffraction spikes of Pluto and Charon away from the moon. Using ephemeris for target 12436-A6-PLUTO ephemeris data for target 12436-A6-PLUTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. A follow-up visit of one orbit to confirm the existence of a small moon of Pluto. ORIENT = 102 selected to keep the moon clear of diffraction spikes. Available around July 22, 2011. (Tic-Visit :proposal-id 12436 :visit-id "A6" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:42.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 22896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "A6" :obset-id "A6" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "A6" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2676 :al-overhead-at-end 0 :internal-dur-at-end 64 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 1 0 One of 7 alternative visit options. Schedule one. ORIENT constraints vary by date to keep the diffraction spikes of Pluto and Charon away from the moon. Using ephemeris for target 12436-A7-PLUTO ephemeris data for target 12436-A7-PLUTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. A follow-up visit of one orbit to confirm the existence of a small moon of Pluto. ORIENT = 110 selected to keep the moon clear of diffraction spikes. Available around July 23, 2011. (Tic-Visit :proposal-id 12436 :visit-id "A7" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:43.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 22896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "A7" :obset-id "A7" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "A7" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2676 :al-overhead-at-end 0 :internal-dur-at-end 64 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 1 0 One of 7 alternative visit options. Schedule one. ORIENT constraints vary by date to keep the diffraction spikes of Pluto and Charon away from the moon. Using ephemeris for target 12436-A8-PLUTO ephemeris data for target 12436-A8-PLUTO does not cover planning interval. Physical constraints are assumed to be unschedulable outside of the ephemeris data. Planning interval: 11.148 to 12.183. ephemeris interval: 11.181 to 13.182 The scheduling data was generated by CASM 19.3. CASM was run in Phase II mode. A follow-up visit of one orbit to confirm the existence of a small moon of Pluto. Beyond July 23, we are unable to predict the orbit reliably, so we will let diffraction spikes fall where they may. (Tic-Visit :proposal-id 12436 :visit-id "A8" :proposal-version -1 :trans-version "20110509" :date "04-Jul-2011 15:54:44.0" :trans-errors '(:WARNINGS 0 :ERRORS 0 :HEALTH-AND-SAFETY 0 :FATAL-ERRORS 0 :CONTINUABLE-FATALS 0) :number-of-orbits 1 :saa-model "29" :si-bright-earth-limb-angle 20.0 :data-volume 22896 :tdrss-contact-duration 0 :coron NIL ) (Tic-Obset :proposal-id 12436 :visit-id "A8" :obset-id "A8" :pcs-mode "FGS" ) (Tic-Orbit :proposal-id 12436 :visit-id "A8" :orbit-number 1 :pcs-time 333 :si-vis-utilization 2666 :al-overhead-at-end 0 :internal-dur-at-end 64 :dark-offset NIL :dark-utilization 0 :max-dark-utilization 1920 :low-sky "N" :pcs-visibility 3021 :pcs-gap 0 ) true 1 0 One of 7 alternative visit options. Schedule one. ORIENT constraints vary by date to keep the diffraction spikes of Pluto and Charon away from the moon.