  There is a growing interest in Lunar exploration fed by the perception that
the Moon can be made accessible to low-cost missions in the next decade. The
on-going projects to set a communications relay in Lunar orbit and a deep space
Gateway, as well as the spreading of commercial-of-the shelf (COTS) technology
for small space platforms such as the cubesats contribute to this perception.
Small, cubesat size satellites orbiting the Moon offer ample opportunities to
study the Moon and enjoy an advantage point to monitor the Solar System and the
large scale interaction between the Earth and the solar wind. In this article,
we describe the technical characteristics of a 12U cubesat to be set in polar
Lunar orbit for this purpose and the science behind it. The mission is named
EarthASAP (Earth AS An exoPlanet) and was submitted to the Lunar Cubesats for
Exploration (LUCE) call in 2016. EarthASAP was designed to monitor hydrated
rock reservoirs in the Lunar poles and to study the interaction between the
large Earth's exosphere and the solar wind in preparation for future
exoplanetary missions.
