LAVA TUBES HAVE BEEN STUDIED ON EARTH SINCE THE LATE 1960S WHEN GEOLOGISTS OBSERVED ACTIVE LAVA TUBES ON HAWAII. TUBES ON OTHER PLANETARY BODIES HOWEVER HAVE ONLY BEEN STUDIED THROUGH REMOTE SENSING. IN AS EARLY AS THE MID 1970S IT WAS POSTULATED THAT THESE PLANETARY TUBES COULD PROVIDE SAFE HAVENS FOR HUMAN CREWS AND PROTECT THEIR LIFE SUPPORT EQUIPMENT FROM HARMFUL RADIATION RAPIDLY FLUCTUATING SURFACE TEMPERATURES AND EVEN METEORITE IMPACTS. WHAT IS NOT CLEAR HOWEVER IS HOW A HUMAN CREW WILL CHARACTERIZE A TUBE-RICH ENVIRONMENT IN PREPARATION FOR HABITATION. THE PROPOSED WORK WILL ADDRESS THIS KNOWLEDGE GAP USING A SUITE OF INSTRUMENTS IN AN ANALOG STUDY. GROUND PENETRATING RADAR (GPR) LIGHT DETECTION AND RANGING (LIDAR) AND HANDHELD X-RAY FLUORESCENCE SPECTROSCOPY (HXRF) ARE ALL TECHNIQUES THAT HAVE BEEN DEPLOYED ON EARTH IN A VARIETY OF GEOLOGIC CONTEXTS WITH GREAT SUCCESS. THEY HAVE NEVER BEFORE BEEN COMBINED IN A VOLCANIC SETTING TO INVESTIGATE LAVA FLOW EMPLACEMENT PROCESSES NOR HAVE ANY OF THEM BEEN APPLIED TO DEVELOP HUMAN EXPLORATION STRATEGIES FOR THE EXAMINATION OF ANOTHER PLANETARY SURFACE. WE PROPOSE TO BOTH INVESTIGATE THE COMBINATION OF THESE FIELD TECHNOLOGIES IN THE DEVELOPMENT OF A STRATEGY FOR THE EXPLORATION OF LAVA TUBE AND PIT-RICH ENVIRONMENTS AS WELL AS TO ADVANCE GPR PROCESSING TECHNIQUES IN AN EFFORT TO AID IN DETAILED CHARACTERIZATION OF THESE SUBSURFACE FEATURES. IN ORDER TO DEVELOP THIS CONCEPT OF OPERATIONS FOR TUBE EXPLORATION WE WILL DEPLOY GPR LIDAR AND HXRF FIELD INSTRUMENTS AT THE LAVA BEDS NATIONAL MONUMENT (LAVA BEDS NM) CALIFORNIA. LAVA TUBES AT LAVA BEDS NM RANGE IN LENGTH DEPTH AND COMPLEXITY. THIS RANGE OF COMPLEXITY IS PARTICULARLY WELL-SUITED TO THIS PROJECT AS TUBE GEOMETRY PRESENT ON OTHER PLANETARY SURFACES IS COMPLETELY UNKNOWN. WE WILL ACCOMPLISH THIS WORK THROUGH THE COMPLETION OF FIVE TASKS IN TWO PSTAR FIDELITY AREAS: 1. DEFINE THE INSTRUMENTATION SUITE NECESSARY FOR LAVA TUBE EXPLORATION AND CHARACTERIZATION (SCIENCE OPERATIONS) 2. DEVELOP A GPR LIBRARY OF WHAT DIFFERENT TUBE AND PIT GEOMETRIES WILL LOOK LIKE (SCIENCE OPERATIONS) 3. DEVELOP AN EXPLORATION STRATEGY FOR HOW A ROVER SHOULD CHARACTERIZE A TUBE/PIT-RICH ENVIRONMENT (SCIENCE OPERATIONS) 4. IDENTIFY OPTIMAL GPR ANTENNA PARAMETERS (TECHNOLOGY) 5. IDENTIFY OPTIMAL GPR DATA PROCESSING METHODS (TECHNOLOGY) TOGETHER THESE SCIENCE OPERATIONS (DECISION-MAKING PROTOCOLS TRAVERSE PLANNING AND NAVIGATION UNIQUE TO SCIENCE SUPPORT) AND TECHNOLOGY OBJECTIVES (THE USE OF MOBILE SCIENCE PLATFORMS INTELLIGENT SYSTEMS AND HUMAN/ROBOTIC INTERFACES AND INSTRUMENT PACKAGES) DIRECTLY APPLY TO THE PSTAR CALL AND ARE THEREFORE RELEVANT TO BOTH THIS PROGRAM CALL AND TO NASA. WE ALSO NOTE THAT CAVES ON OTHER PLANETARY SURFACES HAVE BEEN HIGHLIGHTED AS A POTENTIAL PLACE TO PRESERVE SIGNATURES OF LIFE MAKING THIS STUDENT APPLICABLE TO NASA'S CURRENT HIGH PRIORITY OBJECTIVE OF LOCATING SIGNS OF LIFE ON OTHER PLANETARY SURFACES.