  Propagation of cosmic rays (CRs) from their sources to the observer is
described mainly as plain diffusion at high energies, while at lower energies
there are other physical processes involved, both in the interstellar space and
in the heliosphere. The latter was a subject of considerable uncertainty until
recently. New data obtained by several CR missions can be used to and the local
interstellar spectra (LIS) of CR species that would significantly reduce the
uncertainties associated with the heliospheric propagation. In this paper we
present the LIS of CR protons and helium outside the heliospheric boundary. The
proposed LIS are tuned to accommodate both, the low energy CR spectra measured
by Voyager 1, and the high energy observations publicly released by BESS,
Pamela, AMS-01 and AMS-02. The proton and helium LIS are derived by combining
CR propagation in the Galaxy, as described by GALPROP, with the heliospheric
modulation computed using the HelMod Monte Carlo Tool. The proposed LIS are
tuned to reproduce the modulated spectra for both, high and low, levels of
solar activity.
