SCIENCE GOALS AND OBJECTIVES: ULTRALOW-FREQUENCY (ULF) WAVES IN THE EARTH S INNER MAGNETOSPHERE PLAY A CRUCIAL ROLE IN DYNAMICS OF RING CURRENT AND RADIATION BELTS. AMONG THESE WAVES PI2 PULSATIONS CHARACTERIZED BY THEIR FREQUENCIES OF 6-25 MHZ AND DURATIONS OF 10-15 MIN HAVE LONG BEEN DRAWING PARTICULAR INTEREST BECAUSE OF THEIR FREQUENT ASSOCIATIONS WITH SUBSTORMS. ONE OF CURRENT MAJOR THEORIES PROPOSES THAT BURSTY FLOW ENHANCEMENTS IN THE TAIL PLASMA SHEET CREATES THE INITIAL ENERGY SOURCE IN THE FORM OF COMPRESSIONAL WAVES AND IT IS THE EARTHWARD PROPAGATION OF THE WAVES TO THE INNER MAGNETOSPHERE THAT CAUSES INNER MAGNETOSPHERIC PI2 PULSATIONS. THEREFORE A KEY TO THIS PROPOSED MECHANISM IS TO UNDERSTAND GENERATION OF COMPRESSIONAL PI2 WAVES IN THE TAIL BY FAST FLOWS AND THEIR INWARD PROPAGATION TO THE INNER MAGNETOSPHERE. SINCE DIRECT OBSERVATIONAL EVIDENCE FOR THIS EARTHWARD PROPAGATION CANNOT BE PROVIDED BY SINGLE SPACECRAFT OUR SCIENCE GOAL IS TO ADDRESS THESE TWO OUTSTANDING QUESTIONS WITH SIMULTANEOUS MEASUREMENTS FROM MULTI SPACECRAFT THAT ARE ALIGNED RADIALLY.