SCIENCE GOALS AND OBJECTIVES: INTERSTELLAR NEUTRAL (ISN) ATOMS PENETRATING THE HELIOSPHERE PROVIDE A REMOTE DIAGNOSTIC OF THE VERY LOCAL INTERSTELLAR MEDIUM (VLISM). FLUXES OF ISN ATOMS ARE MODIFIED IN THE OUTER HELIOSHEATH BY CHARGE EXCHANGE (CX) COLLISIONS WHICH RESULT IN THE PRODUCTION OF SECONDARY ISN ATOMS. A LARGE PART OF OUR UNDERSTANDING OF THE VLISM AND THE OUTER HELIOSPHERE COMES FROM THE ATTENUATION OF THE ISN SIGNAL AS OBSERVED AT 1 AU TO THE SOURCE THAT LIES OUTSIDE THE HELIOSPHERE. FOR THIS REASON DETAILS OF THE CX PROCESS ARE CRUCIAL FOR INTERPRETATING THE PLASMA PROPERTIES IN THE HELIOSPHERE AND ITS VICINITY. SO FAR ANALYSES OF THE ISN ATOM OBSERVATIONS FROM IBEX-LO AND ULYSSES/GAS HAVE NEGLECTED ELASTIC SCATTERING AND ASSUMED THAT PARTICLES IN CX COLLISIONS CONSERVE MOMENTA OF PARENT PARTICLES I.E. THAT