Data relay for Earth, Moon and Mars missions

ESA is setting up the future sustainable European Data Relay mission in geostationary orbit. An outline of the driving user needs, the key system trade off and associated technological challenges as well as the overall partnership strategy with the commercial stakeholders is being described. In frame of the European activities for human exploration a mission concept for an early data relay service and a first Moon lander was elaborated as a joint mission proposal. This mission provides low power communication between the lunar surface and Earth as well as early positioning services on the Moon surface for the first lunar explorers. The Data Relay for Moon (DROM) spacecraft will be launched together with the Moon lander and the combined mission is called the Moon Orbiter and Lander (MOL). One attractive feature of the proposed concept is that the DROM spacecraft will establish a high data rate link between the Moon orbit and the Earth. However, high data rates are not required for the early part of the mission. The DROM payload will be used in his early life span to map the lunar surface with high resolution and will use the data relay link to deliver these data to Earth stations. The third part of this paper is to elaborate concepts for high data rate communication between the Mars surface and the Earth supporting Human exploration of Mars.