  We measure the power and spectral index anisotropy of high speed solar wind
turbulence from scales larger than the outer scale down to the ion gyroscale,
thus covering the entire inertial range. We show that the power and spectral
indices at the outer scale of turbulence are approximately isotropic. The
turbulent cascade causes the power anisotropy at smaller scales manifested by
anisotropic scalings of the spectrum: close to k^{-5/3} across and k^{-2} along
the local magnetic field, consistent with a critically balanced Alfvenic
turbulence. By using data at different radial distances from the Sun, we show
that the width of the inertial range does not change with heliocentric distance
and explain this by calculating the radial dependence of the ratio of the outer
scale to the ion gyroscale. At the smallest scales of the inertial range, close
to the ion gyroscale, we find an enhancement of power parallel to the magnetic
field direction coincident with a decrease in the perpendicular power. This is
most likely related to energy injection by ion kinetic modes such as the
firehose instability and also marks the beginning of the dissipation range of
solar wind turbulence.
