Farrell, William - Spacecraft-NEO water interaction during the Asteroid Redirect Mission (ARM)

In the asteroid redirect mission, a robotic spacecraft will collect a 5 to 7-m near-Earth object (small asteroid) and place it in orbit about the Moon. Subsequent manned sorties will then visit the asteroid in lunar orbit via the Orion spacecraft. However, any manned spacecraft will have its own water-rich exosphere, this water being outgassed from the spacecraft body and emitted directly via water dumps. This man-made exosphere will interact with the asteroid surface, possibly leading to the accumulation of contaminating water at cooler or shadowed locations on the body. In this presentation we consider the accumulation of spacecraft water emission at the asteroid. We will use the space shuttle water cloud examined in great detail in the mid-1980s as an analog. We will especially examine the water accumulation on the NEO as a function of assumed body temperature profiles. While a spacecraft-delivered contaminating water cloud might be considered a drawback, we suggest herein to use the water emission in a set of active experiments to gain new insight into the enigmatic water molecule-surface interactions that occur at the Moon and airless bodies. For example, past NLSI and SSERVI science studies suggests that defects can be sites for increased water adsorption. We thus suggest the astronauts can create a ‘defect garden’ that includes upturned asteroid soil, fractured soils (by astronaut impacts via hammer), and irradiated soils all designed to determine changes in in-situ surface water retention.