Humans to Mars

The story of the dreams and the unbuilt spaceships for flights to Mars should be recorded so that in the future people can examine past ideas of space travel just as we can examine the unconsummated ideas of Leonardo da Vinci by reading his notebooks. Years from now people should be able to decide for themselves whether they want to go to Mars or if they prefer to stay earthbound. But let us not destroy the dream, simply because we do not wish to pursue it ourselves. (Edward Ezell, 1979)1 In the past half century, visionary engineers have made increasingly realistic plans for launching astronauts to Mars to explore the planet. This monograph traces the evolution of these plans, taking into account such factors as on-going technological advancement and our improving knowledge of the red planet.