All three of the founders of the Space Frontier Foundation, an organization dedicated to opening the space frontier to human settlement, were supporters of O'Neill's ideas and had worked with him in various capacities at the Space Studies Institute. One of them, Rick Tumlinson, describes three men as models for space advocacy: Wernher von Braun, Gerard K. O'Neill, and Carl Sagan. Von Braun pushed for "projects that ordinary people can be proud of but not participate in". Sagan wanted to explore the universe from a distance. O'Neill, with his grand scheme for settlement of the Solar System, emphasized moving ordinary people off the Earth "en masse".