MULTI PURPOSE CREW VEHICLE NONLINEAR DEEP DIVE. BASED ON OBSERVATIONS OF THE MULTI PURPOSE CREW VEHICLE NONLINEAR DEEP DIVE EUROPEAN SERVICE MODEL STRUCTURAL TEST ARTICLE TEST DATA, THE MODEL RESPONSE IS BEING DRIVEN BY NONLINEARITIES IN THE INTERCONNECTS BETWEEN AND INTERNAL TO THE EURORPEAN SERVICE MODEL. THE PROBLEM IS MADE MORE DIFFICULT DUE TO THE SIZE AND INTERNAL STIFFNESS OF THE MODULES THEMSELVES. THESE STIFFNESS AND LOSS FACTORS NEED TO BE DEFINITIVELY IDENTIFIED IN TIME FOR THE VERIFICATION LOADS AND ANALYSES TO LOWER THE STATIC EQUIVALENT LOADS SUFFICIENTLY TO ESTABLISH POSITIVE MARGINS. DISTINCT APPROACHES ARE INCLUDED FOR CONSIDERATION ON THE PATH FORWARD IN MODAL TEST OF THE MULTI PURPOSE CREW VEHICLE STACK ON A FLIGHT EQUIVALENT MSA AND FOR CORRELATION IN THE STATIC TEST. SEVERAL JOINTS WILL BE ASSESSED FOR NONLINEAR BEHAVIOR FROM THE STATIC TEST EVALUATION.