THE PROPOSED INSTRUMENT DEFINITION STUDY HAS THREE BROAD OBJECTIVES: 1. DEVELOP SPECIFICATIONS FOR AN ORBITAL LV SEISMOMETER USABLE AROUND A SMALL BODY: (A) DEFINE LASER POWER REQUIREMENTS FOR COMET AND ASTEROID OPTICAL REFLECTIVITIES; (B) SPECIFY LENS GEOMETRY TO ACHIEVE SMALL LASER SPOTS ON THE SURFACE FROM DIFFERENT ORBITAL RADII; (C) DESIGN ORBITAL CONOPS STRATEGIES WITH SUFFICIENT OBSERVATION TIME AT EACH SURVEY LOCATION. [PI SAVA&COI ASPHAUG] 2. ADAPT 3D SEISMIC IMAGING TO LV SEISMIC DATA: (A) SIMULATE FULL WAVEFIELDS CONSISTENT WITH ORBITAL LV ACQUISITION; (B) DEVELOP METHODS FOR LV SEISMIC IMAGING FOR PASSIVE (E.G. TIDAL DISSIPATION; THERMAL CRACKING; NUCLEUS VENTING) OR ACTIVE SOURCES; (C) CORRECT FOR LASER BEAM ORIENTATION RELATIVE TO THE TARGET SURFACE; (D) ACQUIRE MULTICOMPONENT SEISMIC DATA WITH LVS AT DIFFERENT VANTAGE POINTS (MULTIPLE SPACECRAFT). [PI SAVA] 3. DEMONSTRATE LV SEISMOLOGY ON A SMALL BODY SUBJECT TO PASSIVE OR ACTIVE SOURCES: (A) BUILD REALISTIC INTERNAL MODEL STRUCTURES FOR PHOBOS AND 67P/C-G AS TYPE EXAMPLES; (B) EVALUATE OPTIMAL ACQUISITION AND PROCESSING PARAMETERS; (C) QUANTIFY THE ATTAINABLE RESOLUTION AND REQUIRED MISSION DURATION. [COI ASPHAUG&PI SAVA] THE PROPOSED SOLVE INSTRUMENT WILL BE USABLE FOR ANY MISSION TO A SMALL BODY UNDER THE DISCOVERY OR NEW FRONTIERS PROGRAMS. THIS PICASSO PROJECT WILL BRING THE SOLVE TRL FROM 2 TO 3 RESULTING IN A FULLY-DEFINED INSTRUMENT AND DATA PROCESSING FLOW TO BE FURTHER DEVELOPED IN A MATISSE FUNDED PROJECT.