Speleology by a large number of human activities. Dam construction, limestone quarrying, water pollution and logging are just some of the disasters that can devastate or destroy underground biological communities. Speleologists also work with archaeologists in studying underground ruins, tunnels, sewers and aqueducts, such as the various inlets and outlets of the Cloaca Maxima in Rome. Speleology Speleology is the scientific study of caves and other karst features, their make-up, structure, physical properties, history, life forms, and the processes by which they form (speleogenesis) and change over time (speleomorphology). The term "speleology" is also sometimes applied to the recreational activity of
Exploration Systems Architecture Study planned Crew Exploration Vehicle (CEV) acquisition strategy designed by his predecessor Sean O'Keefe. Griffin's plans favored a design he had developed as part of a study for the Planetary Society, rather than the prior plans for a Crew Exploration Vehicle developed in parallel by two competing teams. These changes were proposed in an internal study called the Exploration Systems Architecture Study, whose results were officially presented during a press conference held at NASA Headquarters in Washington, D.C. on September 19, 2005. The ESAS includes a number of recommendations for accelerating the development of the CEV and implementing Project Constellation, including