Human exploration of near Earth Asteroids: Architecture of proximity operations

• A robotic precursor can improve the safety and science yield of a human mission.
• The human spacecraft does not land on the asteroid but is placed on a stable orbit.
• Astronauts explore the asteroid surface with a Proximity Maneuvering Vehicle (PMV).
• Science is performed through robots directly controlled by astronauts on the PMV.

This paper outlines the strategic approach to realize a human mission to an asteroid, focusing specifically on the proximity operations. The risks and challenges posed by asteroid surfaces to in-situ investigations force the proximity operations to be done by the intermediary of robotic explorers. In this architecture, a precursor is sent years in advance to a potential target asteroids. Its main goals are the characterization of the gravity field and of the surface behavior. If the target is found suitable, the manned mission then proceeds. With their main spacecraft stationed on a stable orbit around the asteroid, the astronauts are transported to the surface via a small, unpressurized spacecraft. Hovering a few meters above the surface, they deploy and command small robotic landers that perform scientific operations at the surface.