The overarching science goal of the Nautilus mission, proposed by a team of European scientists with a strong participation of US scientists, is to explore via rendezvous a volatile-rich asteroid not represented in our meteorite collections (C- or D-type), in order to determine – via the composition of its volatiles – whether this object and by extension all objects sharing the same spectral class formed in the asteroid belt or further away from the sun and whether these objects are the source of Earth’ volatiles. These measurements will ultimately cast light on the early history (dynamical evolution) of the solar system.
In order to simplify the mission, we will target an active main belt asteroid. Active asteroids currently comprise so-called main belt comets (Jewitt 2012) as well as the dwarf planet Ceres (Kuppers et al. 2014). For these objects, the volatiles can be characterized from an orbiter (as performed by Rosetta in the case of 67P), hence without the need of a landing module (or a penetrator).