  New solar wind data from the Voyager 1 and Voyager 2 spacecraft, together
with the SOHO SWAN measurements of the direction that neutral hydrogen enters
into the inner heliosheath and neutral helium measurements provided by multiple
observations are expected to provide more reliable constraints on the
ionization ratio of the local interstellar medium (LISM) and the direction and
magnitude of the interstellar magnetic field (ISMF). In this paper we use
currently the most sophisticated numerical model of the heliospheric interface,
which is based on an MHD treatment of the ion flow and kinetic modeling of
neutral particles, to analyze an ISMF-induced asymmetry of the heliosphere in
the presence of the interplanetary magnetic field and neutral particles. It is
shown that secondary hydrogen atoms modify the LISM properties leading to its
shock-free deceleration at the heliopause. We determine the deflection of
hydrogen atoms from their original trajectory in the unperturbed LISM and show
that it occurs not only in the plane defined by the ISMF and LISM velocity
vectors, but also, to a lesser extent, perpendicular to this plane. We also
consider the possibility of using 2-3 kHz radio emission data to further
constrain the ISMF direction.
