In the early years of the twentieth century, Victor Hess of Germany flew instruments in balloons and so discovered in 1912 that an extra- errestial radiation of unknown origin is incident on the earth with an almost constant intensity at all times. These penetrating non solar radiations which were called Cosmic Rays by Millikan, USA, opened the new frontier of space physics and many leading scientists were attracted to it. At the end of World War II a number of space vehicles, e.g. stratospheric balloons, rockets and satellites were developed. In 1950 and onwards, these vehicles enabled...
In the early years of the twentieth century, Victor Hess of Germany flew instruments in balloons and so discovered in 1912 that an extra- errestial ra...
