Human Mission to Asteroids in the Context of Future Space Exploration Studies

The final goal, for the foreseeable future, of the Human Exploration of the Solar System is to land a crew on the Mars Surface (and to bring it back). A wide array of capabilities has to be developed and demonstrated before attempting such a risky endeavor; intermediate steps are therefore needed, also to comply with budget constraints. Human missions to Near Earth Objects (NEOs) and specifically Asteroids (NEAs) are among the most suitable candidates, thanks to high scientific interest, good opportunities for testing technologies and crew operations, and to mature Earth protection capabilities. In the following, a review of existing NEA Human mission concepts is provided and a new one, characterized by the exploitation of Nuclear Thermal Propulsion to reduce overall lift-off