As we have explained in Chapter 1, the British scientists who were most interested initially in the use of rockets for scientific research were those concerned with the ionosphere so it is not surprising that, since the inception of a rocket research programme, a great deal of attention has been directed towards ionospheric studies. This has involved the use of a wide variety of techniques ranging from ground-based radio tracking of satellites to in situ measurements of ionospheric properties from space vehicles. In fact, as we shall see, much of the work has been concerned with the topside ionosphere and this has naturally connected up with studies of the magnetosphere to which many ionospheric physicists have made major contributions.

Ways and means

At the time when these programmes were planned, most knowledge of the ionosphere was confined to the information obtained from ground-based sounding which basically provided the height profile of electron concentration above the sounding station. Even this was incomplete as explained in Chapter 1, p. 2, especially as it could provide no information about the region above the F layer maximum – the topside ionosphere. No direct method of determining other important ionospheric parameters such as the electron temperature or the positive ion composition was available. By the early 1950s the impact of the new rocket techniques was making itself felt in that exploratory measurements had been made, particularly of the ion composition and of the electron concentration in the gaps in the altitude profile.