Overview

Earth is the cradle of mankind, but one cannot remain in the cradle forever

Konstantin Tsiolkovsky

The earliest periods of mankind's technological development most notably the Stone Age, the Bronze Age and the Iron Age were characterised by resources used in an organised and prolonged manner. The most recent, continuing example is the Space Age, a period of technology development in which the resource is outer space itself.

Although earlier Ages of Man are difficult to date precisely, because of the lack of documentation, this is not the case for the Space Age. The Space Age can be defined as beginning with the launch of Sputnik 1 on 4 October 1957 since, from this point on, organised and prolonged activity in space became possible.

Some historians argue that the first time a rocket flew high enough to cross the notional boundary between the Earth's atmosphere and space marks the beginning of the Space Age, but that was but a prelude to the symphony that followed. Sputnik 1 transmitted its historic beep-beep signal for 21 days and remained in orbit around the Earth for about three months. Although rocket-borne payloads had been flown into space before Sputnik, they were launched on suborbital trajectories (with insufficient energy to reach orbital velocity), allowing them to experience only a few minutes of the space environment before gravity returned them to Earth.

It was the launch of Sputnik 1 which proved that man-made devices could operate in space long enough to perform useful scientific investigations, preparing the way...