ICE GIANTS LIKE URANUS REMAIN POORLY UNDERSTOOD YET WE NOW KNOW THAT THEY ARE PERHAPS THE MOST COMMON TYPE OF PLANETS BASED ON EXOPLANET DETECTIONS. A SATELLITE SYSTEM CAN BE USED TO PLACE IMPORTANT CONSTRAINTS ON THE FINAL STAGES OF A PLANET S FORMATION. HOWEVER THE ORIGIN OF THE URANIAN SATELLITES REMAINS THE LEAST WELL UNDERSTOOD OF ANY OF THE OUTER SATELLITE SYSTEMS. THE LARGE SATELLITES OF JUPITER AND SATURN LIKELY FORMED WITHIN CIRCUMPLANETARY DISKS OF GAS AND SOLIDS THAT WERE CREATED AS THOSE PLANETS ACCRETED GAS (E.G. STEVENSON ET AL. 1986). RETROGRADE TRITON WAS LIKELY CAPTURED INTACT (E.G. AGNOR&HAMILTON 2006) WHICH DESTROYED EVIDENCE OF AN ORIGINAL SATELLITE SYSTEM AT THAT ICE GIANT. IN CONTRAST BASIC PROPERTIES OF THE URANIAN SATELLITE SYSTEM ARE NOT EASILY EXPLAINED BY STANDARD ORIGIN MODELS. THE CHALLENGE IS THAT URANUS IS A RETROGRADE ROTATOR WITH AN OBLIQUITY OF 98 DEGREES AND ITS SATELLITES ORBIT IN THE SAME SENSE AS ITS RETROGRADE ROTATION. THE NEARLY CIRCULAR CO-PLANAR ORBITS OF THE MAIN URANIAN SATELLITES AND THEIR ORBITAL SPACINGS AND MASSES COMPARED TO THAT OF THE PLANET ARE SIMILAR TO JUPITER S MOONS. THIS SUGGESTS THEY MAY HAVE FORMED SIMILARLY VIA CO-ACCRETION. HOWEVER INFLOWING GAS WOULD FORM A PROGRADE DISK AROUND THE PLANET AND A SATELLITE SYSTEM ORBITING IN THE OPPOSITE SENSE TO THAT OBSERVED. ALTERNATIVELY THE SATELLITES COULD HAVE FORMED FROM A DISK PRODUCED BY A GIANT IMPACT THAT TILTED URANUS BUT THE DISKS PRODUCED BY SUCH EVENTS APPEAR TOO COMPACT AND ICE-DOMINATED TO PRODUCE THE OUTER ROCK-RICH URANIAN MOONS. A PROMISING NEW IDEA HAS BEEN PROPOSED (MORBIDELLI ET AL. 2012). THE IDEA IS THAT URANUS ORIGINALLY HAD A SMALLER OBLIQUITY AND A PROGRADE SATELLITE SYSTEM LIKE THAT AT JUPITER. THIS SYSTEM WAS DESTABILIZED BY A URANUS-TIPPING GIANT IMPACT. THE CURRENT SATELLITES THEN RE-ACCRETED IN URANUS NEW EQUATORIAL PLANE FROM DEBRIS CREATED BY DISRUPTIVE COLLISIONS BETWEEN THE ORIGINAL PROGRADE SATELLITES. A FIRST REQUIREMENT FOR THIS SCENARIO IS THAT THE IMPACT MUST PRODUCE NOT ONLY URANUS RETROGRADE OBLIQUITY BUT ALSO A MASSIVE INNER DISK CONTAINING 1% OR MORE OF THE PLANET S MASS OR ROUGHLY 100 TIMES THE MASS OF THE CURRENT SATELLITES. THE GRAVITATIONAL INFLUENCE OF THIS IMPACT-GENERATED DISK IS NEEDED SO THAT OUTER DISK DEBRIS ACCRETES INTO SATELLITES WITH LOW INCLINATIONS CONSISTENT WITH THE CURRENT LOW INCLINATION ORBITS OF TITANIA AND OBERON. A SECOND REQUIREMENT IS THAT THE MASSIVE INNER DISK MUST BE LOST SINCE NO SUCH DISK NOR COMPARABLY MASSIVE INNER MOON EXISTS AT URANUS TODAY. WHETHER SUCH CONDITIONS CAN BE ACHIEVED IS UNCLEAR. IN THIS PROPOSAL WE WILL MODEL THE FORMATION OF THE URANIAN SATELLITES IN A CO-ACCRETION + GIANT IMPACT SCENARIO. IN TASK 1 WE WILL CONDUCT SPH SIMULATIONS OF IMPACTS INTO URANUS TO DETERMINE THE TYPE OF IMPACT NEEDED TO TILT THE PLANET AND GENERATE A SUFFICIENTLY MASSIVE INNER DISK. IN TASK 2 WE WILL MODEL THE ACCRETION OF SATELLITES FROM THE POST-IMPACT SYSTEM IN TWO STAGES. FIRST WE WILL MODEL THE RE-ACCRETION OF THE OUTER REGULAR SATELLITES FROM THE DEBRIS DISK PRODUCED BY COLLISIONS AMONG THE PRIOR MOONS (TASK 2A). THEN WE WILL MODEL THE LATER EVOLUTION OF THE INNER ICE-RICH IMPACT-GENERATED DISK AS IT COOLS AND CONDENSES (TASK 2B). THE GOAL IN TASK 2 IS TO DETERMINE WHETHER THE POST-IMPACT SYSTEM CAN EVOLVE INTO A SYSTEM OF URANUS-LIKE SATELLITES WHILE THE MASSIVE IMPACT-GENERATED DISK IS NEARLY ENTIRELY LOST. TOGETHER TASKS 1 AND 2 WILL ALLOW US TO EVALUATE THE VIABILITY OF A CO-ACCRETION + GIANT IMPACT MODEL.