Our New Domain S carcely twenty years have passed since Russian cosmonaut Yuri Gagarin became the first person to orbit the Earth. In less than a single generation, human beings have extended their domain from the upper fringes of the Earth's atmosphere to the mountains of the Moon. If this human progress continues, we can expect that some of those already born since Gagarin's 1961 flight will walk on Mars and that some of their grandchildren will be born, live, and die in colonies beyond the Earth. There has always been a human drive to expand and explore. The last twenty years have shown that space travel is feasible.
Spaceflight produces many severe atomic stresses on the body and mind.
In space, there is radiation more intense, dangerous, and sometimes quite unlike anything encountered on Earth. Inside a spacecraft, high noise levels are produced by the powerful rocket motors and by the continuous operation of life support machinery. Spaceflight involves long periods of isolation, nagging vibrations, and disturbances in normal day-night cycles. Sun scorches anything that it strikes, and the temperature of shaded objects approaches absolute zero. In the almost perfect vacuum of space, an unprotected human would survive less than a minute before his blood would boil.