Exploration missions in the Sun–Earth–Moon system: A detailed view on selected transfer problems

The Astronautics and Space Station Department of the Universitaet Stuttgart has developed a design environment for the conceptual design of manned space missions. With the assistance of the ESA European Space Operations Center this design environment has been extended to cover exploration missions involving the areas of the collinear Earth–Moon and Sun–Earth libration points, which are of interest as an alternative staging location to the low lunar orbit approach for lunar exploration and for satellite servicing missions, respectively. To allow for a reliable mission design, the transfer times, the ΔVΔV and variations in the ΔVΔV for transfers between the different locations in the Sun–Earth–Moon system must be known, especially taking the rendezvous constraints and safety issues for human spaceflight missions into account. The results of the investigations presented in this paper cover transfer trajectories from Earth to different types of orbits about the collinear Earth–Moon libration points 1 and 2 and further on to the Moon. For the Earth to Earth–Moon libration point transfer, direct trajectories, fly-bys at the Moon and trajectories via the weak stability boundary region of the Sun–Earth system are treated.