In the 1950s, there were no specific space applications as there are now: a description of the early spacecraft in today's terms might be technology demonstrators engaged in scientific measurement of the space environment .

In effect, the spacecraft were conducting what we now call space science . Although the term has been in use for many years, it has no widely agreed definition and some general dictionaries do not even recognise the term. Within the space community, however, space science is understood to be that branch of science concerned with the features and processes of the space environment [including] "space physics" and "space astronomy" ^[1], in other words the science of space . With developments in manned spaceflight, however, the definition has been extended to include topics such as space medicine and microgravity research ( science in space ), but they are beyond the scope of this book.

So while access to space was the remit of the rocket engineer, the development of the payload was largely down to the science community, specifically (since there were no space scientists) the geophysics community. As implied earlier, research was being pursued in parallel by both military and civilian teams, with some degree of cross-fertilisation, but we shall concentrate here on the civilian aspects.