Introduction

Abstract

Space exploration has always fascinated humankind. It has inspired the works of philosophers such as Lucretius, Kepler, and Kant and modern works of fiction by Jules Verne, Isaac Asimov, Arthur C. Clark, Fred Hoyle, and Italo Calvino. These works are not only pleasant entertainment but also ways to expand our imagination. They allow us to explore human responses to future scientific developments and to speculate on how they might develop. In the second half of the twentieth century, space exploration moved away from the realm of pure imagination. Sputnik and Soviet astronauts (beginning with Yuri Gagarin) orbiting the Earth and American astronauts landing on the Moon created an atmosphere of optimism. Optimism pervaded science, the public, and the arts, as Stanley Kubrick’s film 2001: A Space Odyssey explored the possible origins and fate of humankind in space.

Earth is the cradle of humanity, but one cannot live in a cradle forever.

(Konstantin E. Tsiolkovsky)