  A problem of determining attainable landing sites on the surface of Venus is
an essential part of the Venera-D project aimed to explore the planet using a
lander. This problem appears due to the inability for the descent module to
land at any point on the surface of Venus because of the short duration of the
launch window (about 2 weeks from the optimal launch date), as well as
restrictions on the maximum permissible overload. An additional factor
affecting the reduction of attainable landing sites is the low angular velocity
of Venus own rotation. This study proposes a new approach to expand the
attainable landing areas. The approach is based on the use of the gravitational
field of Venus to transfer the spacecraft to an orbit resonant to the Venusian
one with a ratio of periods of 1:1. All the simulations were performed at the
patched conic approximation. As an example, we considered a flight to Venus at
launch in 2029 or 2031. For both cases maps of attainable landing areas on the
surface were constructed. It has been demonstrated that there is always at
least one launch date within the launch window, allowing the spacecraft to
reach almost any point on the surface of Venus. It is shown that the
application of the proposed approach makes it possible to achieve a significant
expansion of the attainable landing areas (over 70\% of the surface) and, in
some cases, provide access to any point on the surface of Venus. However, the
price of this advantage is an increase in the flight duration by one Venusian
year.
