Heinlein is a crater in Promethei Terra, Mars. Heinlein helped to narrate the Moon landing with Walter Cronkite on CBS in 1969. He was involved in the planning of the Star Wars Defense program in the 1980s. (wikipedia entry)
A crater is a circular depression likely created by an impact event. On Mars large craters are named after deceased scientists, writers and others who have contributed to the lore of Mars. Small creaters (less than 60km) are named after small towns and villages.