Contains G E Perry's paper: 'The determination of a satellite's orbital period from many simultaneous observations', progress reports and observations, predictions and other paperwork for the project, G E Perry's letter to the Scientific Research Station at Jungfraujoch in Switzerland with respect to the project, "Computer processed results for various periods of evening visibility", Kettering Grammar School Echo 2 Project (sheets, log books, results); Blue book - visual observations when in Gibraltar (includes also shipping lists and movements, and detail of photographs taken)