History of Mars Ascent Vehicle development over the last 20 years

The Mars Ascent Vehicle concept has seen many studies and development efforts over the last 20 years, up to efforts currently underway by the Mars Program Office. A wide range of concepts have been explored, and many participants over time have been involved. This paper will give an overview of this colorful history, including the context for the individual efforts, the people and organizations involved, and some details of various MAV concepts that have been considered.