LANDER-STYLE VEHICLE PLUME-STRUCTURE HEAT TRANSFER MONITORING KNOWLEDGE PAYLOAD PROPOSAL LEAD: STEVEN H. COLLICOTT PURDUE UNIVERSITY CO-INVESTIGATORS AND/OR COLLABORATORS AS MAY BE KNOWN AT THIS TIME: NONE LUNAR AND PLANETARY LANDER STYLE OF ROCKETS INHERENTLY PLACE LEGS CLOSE TO A ROCKET PLUME ESPECIALLY THE NEWEST GENERATION OF COMMERCIAL LUNAR LANDERS. THE RADIATIVE HEATING OF THE LEGS BY THE UNSTEADY PLUME FROM AN ACTIVELY GIMBALLED AND THROTTLED ROCKET MOTOR IS IMPORTANT TO UNDERSTAND AND PREDICT WELL FOR FUTURE LANDING VEHICLES. THIS IS EVEN A LITTLE MORE DIFFICULT IN-FLIGHT TESTING ON EARTH BECAUSE CROSS WINDS WHICH ARE OF COURSE ABSENT ON MOON AND NEARLY ABSENT ON MARS DELIVER ADDITIONAL AND ASYMMETRICAL HEAT TRANSFER FROM PLUME TO LEGS. MEASUREMENTS DURING FLIGHT TESTING ARE NECESSARY TO BUILD UP KNOWLEDGE ABOUT DIFFERENCE CONDITIONS FROM HIGH THRUST TO IDLE AND FROM CENTERLINE THRUST TO HARD-OVER GIMBALLED OPERATIONS. PROPOSED IS AN EXPANSION OF ONE PIECE OF EXISTING FLIGHT HARDWARE AT PURDUE TO ACCOMMODATE MANY MORE TEMPERATURE MEASUREMENTS ON LANDER LEGS DURING FLIGHT TESTS. THE PRESENT PAYLOAD HAS LAUNCHED TWICE ON EXOS TEST FLIGHTS NEITHER OF WHICH HAS REACHED INTENDED ALTITUDE BUT HAVE TRAVELLED WELL ABOVE ALTITUDES FLOWN REGULARLY TO DATE BY MASTEN AND RETURNED SAFELY. OUR DATA RETURNED TEMPERATURE AND LOW-RESOLUTION ACCELERATION DATA FROM BOTH DAYS. THIS PAYLOAD ONE OF TWO PARTS IN WHAT IS CALLED THE PURDUE RESEARCH AND EDUCATIONAL FACILITY ON EXOS ROCKETS OR PREFER IS EASILY DUPLICATED TO FLY ON MASTEN TO MEASURE MANY MORE CHANNELS OF TEMPERATURE THAN THE THREE IT MEASURES ON EXOS FLIGHTS. THREE POINTS SUFFICED FOR THE ORIGINAL PAYLOAD AND THE PROPOSED MODIFICATION WILL INCREASE THE CAPABILITY TO SEVERAL DOZEN SENSORS. THIS ALLOWS INSTRUMENTING OF ALL LEGS OF THE MASTEN VEHICLE. IT IS ANTICIPATED THAT FOLLOWING GROUND-TESTING AT PURDUE TO ASSURE OPERATIONAL READINESS NUMEROUS FLIGHTS WILL BE MADE WITH ONE PAYLOAD ON PERHAPS MULTIPLE VEHICLES FROM MASTEN (OR ANY OTHER LANDER-STYLE ROCKET WHICH REACHES THE MARKETPLACE). WHEN MEASUREMENTS FROM NUMEROUS FLIGHTS AND CONDITIONS ARE COMPARED TO PREDICTIONS FROM MODELING THEN SPECIFIC MODEL IMPROVEMENTS WILL BE KNOWN TO BE NEEDED.