OPTICAL LINKS TO SMALL SPACECRAFT OFFER THE POTENTIAL FOR HIGH ACCURACY ORBIT DETERMINATION NAVIGATION AND HIGH BANDWIDTH COMMUNICATIONS FOR SATELLITES THAT ARE SIZE AND POWER CONSTRAINED. ONE OF THE KEY PERFORMANCE DRIVERS FOR THESE SYSTEMS IS TIMING. NEARLY ALL SPACE NAVIGATION SYSTEMS RELY ON THE LIGHT-TRAVEL TIME CALCULATIONS AND DATA THROUGHPUT FOR FREE-SPACE OPTICAL COMMUNICATIONS SYSTEMS DEPEND ON THE TIMING RESOLUTION WITH WHICH LASER PULSES CAN BE EMITTED AND DETECTED. WE WILL DEMONSTRATE PRECISION GROUND-TO-SPACE CLOCK SYNCHRONIZATION USING A SEQUENCE OF SHORT OPTICAL PULSES EXCHANGED BETWEEN AN OPTICAL GROUND TERMINAL AND AN ORBITING 3U CUBESAT. THE CUBESAT WILL BE INTEGRATED WITH THE NOVEL 1U OPTICAL PRECISION TIME-TRANSFER INSTRUMENT (OPTI) WHICH HAS BEEN DEVELOPED TO TRL 5 AT THE UNIVERSITY OF FLORIDA (UF) UNDER AN AIR FORCE RESEARCH LABORATORY (AFRL) GRANT. THE LAB DEMONSTRATED PERFORMANCE OF THIS INSTRUMENT IS 100 PS THE TIME IT TAKES LIGHT TO TRAVEL JUST 3 CM. IT WILL BE INTEGRATED INTO A 3U CUBESAT BUS ASSUMED TO BE DEVELOPED BY THE NASA AMES RESEARCH CENTER (ARC) AND DERIVED FROM ARC S EDSN CUBESAT BUS. THIS CUBESAT MISSION CHOMPTT (CUBESAT HANDLING OF MULTISYSTEM PRECISION TIME TRANSFER) HAS ALREADY BEEN SELECTED FOR LAUNCH IN 2017 BY NASA S CUBESAT LAUNCH INITIATIVE PROGRAM. THE OPTICAL TERMINAL WILL BE LOCATED AT A FACILITY LOCATED AT THE KENNEDY SPACE CENTER IN FLORIDA AND MANAGED BY THE UNIVERSITY OF CENTRAL FLORIDA. THIS TECHNOLOGY WILL ALLOW EARTH ORBITING NANOSATELLITES TO PRECISELY CORRELATE ASTRONOMICAL OR EARTH OBSERVATIONS OR TO COORDINATE SPACECRAFT FLYING IN FORMATION TO PRODUCE A DISTRIBUTED APERTURE TELESCOPE. NEW PRECISION CLOCKS LIKE JPL S DEEP SPACE ATOMIC CLOCK CAN BE VALIDATED IN SPACE USING THIS LOW-COST APPROACH RATHER THAN THE DSN. FARTHER IN THE FUTURE WE CAN ENVISION USING THIS OPTICAL GROUND SYSTEM TO PROVIDE PRECISION ORBIT DETERMINATION AND COMMUNICATIONS FOR NANOSATELLITES FLYING BEYOND THE GPS SPHERE OR TO ENABLE SMALL SATELLITES TO PROVIDE NAVIGATION SOLUTIONS AND DATA RELAYS TO HUMAN OR ROBOTIC EXPLORERS OPERATING NEAR THE MOON OR MARS.