Many of the problems we have experienced in Europe in this field so far are attributable to the lateness and difficulties of establishing with users, what systems they would like to see in an operational role. These remarks, of course, relate particularly to the application satellites, and not to the scientific sector of the work, which has enjoyed a great degree of interest by the scientific community in calling for various experiments to be incorporated in spacecraft. As a result of this in Europe, we have seen through ESRO and through national programmes, a considerable degree of achievement in spacecraft which have been orbited, and which in nearly all cases have been very successful and have met or exceeded their design life. Through this work, therefore, there exists an extremely valuable baseline of experience, both in the establishments and the institutions concerned with specifying, planning, and managing the programmes on behalf of the scientists, and also in industry that has developed the equipment for these programmes.