Abstract: This proposal seeks funding to continue the neutron monitor observations at McMurdo for at least 4 years of operation - through the next solar activity maximum predicted in 2011-12. The neutron monitor in McMurdo is a crucial element of the 'Spaceship Earth' array - a 12-station multi-national network of neutron monitors optimized to measure the angular distribution of relativistic solar cosmic rays. McMurdo has the southernmost viewing direction of any neutron monitor station in the World, thereby providing a critical three-dimensional perspective on the cosmic ray distribution measured by the global array. Data returned from McMurdo and other 'Spaceship Earth' stations will enable the advanced understanding of the acceleration and transport of solar energetic particles, and of the transient and long-term modulation of galactic cosmic rays by the Sun. From the historical occurrence rates, continuing McMurdo observations through the solar activity maximum would allow to detect new relativistic solar particle events. Neutron monitors can play a direct role in forecasting and specifying solar wind disturbances, thus improving the capability to forecast major space weather events for the societal benefit. For example, providing the cosmic rays Ground-Level Enhancement (GLE) alerts is of direct relevance to aviation flights over high latitudes where these events can pose health hazards.