New Approaches for Human Deep-Space Exploration.

We are undertaking a Russian-American study of orbital options to extend human exploration beyond the Moon's orbit. For a viable program, an international collaboration (as now for the ISS) and reusable spacecraft will be needed. With reusable spacecraft, high-energy Earth orbits can be drastically modified with lunar swingbys and small maneuvers near the edge of the Earth's gravitational sphere of influence, especially near the collinear Sun-Earth and Earth-Moon libration points, to reach desired destinations. The work will build on ideas developed by the International Academy of Astronautics' exploration study group presented at the 2008 International Astronautical Congress in Glasgow. The first efforts could support backside lunar exploration from an Earth-Moon L2 temporary Lissajous or relatively permanent halo orbit; some quick low post-launch ΔV trajectories are presented. In a stepping stone approach, later missions could service large space telescopes near the Sun-Earth L2 libration point; explore near-Earth asteroids; and then the moons of Mars. The study will use highly-elliptical Earth orbits whose line of apsides can be rotated using lunar swingbys; then a propulsive maneuver, considerably smaller than that needed from a circular low-Earth orbit, can be applied at the right perigee to send the spacecraft on the right departure asymptote to a desired destination. [ABSTRACT FROM AUTHOR]