The 10th ESLAB Symposium was held at Grossenzersdorf near Vienna on 10-13 June 1975 under the title 'The Scientific Satellite Programme During the Inter national Magnetospheric Study'. The Symposium was attended by an invited audience of 60 scientists from the ESA Member States, the United States, Japan, Canada and Austria. Following a report by the joint COSPAR-IUCSTP Special Working Group, the International Magnetospheric Study (lMS) is proposed as an international co operative enterprise of limited duration, having as its principal objective the achie vement of a comprehensive, quantitative understanding of the dynamical processes operating in the Earth's plasma and field environment. In order to accomplish this objective, it is thought to be necessary to carry out simultaneous measurements with nearly identical instrumentation at various points in space. These measurements will need to be made in combination with appropriate observations at or near the Earth's surface. Besides near-Earth observations by ground-based, rocket- and balloon-borne instrumentation, satellite investigations are expected to make an important contri bution to the IMS. A number of satellites assigned to magnetospheric research have recently been launched, or will be launched shortly, to be operational during the IMS. The European Space Agency has devoted two of its forthcoming scientific satellites - GEOS and ISEE-B - to magnetospheric and interplanetary research.

The 10th ESLAB Symposium was held at Grossenzersdorf near Vienna on 10-13 June 1975 under the title 'The Scientific Satellite Programme During the Inter national Magnetospheric Study'. The Symposium was attended by an invited audience of 60 scientists from the ESA Member States, the United States, Japan, Canada and Austria. Following a report by the joint COSPAR-IUCSTP Special Working Group, the International Magnetospheric Study (lMS) is proposed as an international co operative enterprise of limited duration, having as its principal objective the achie vement of a comprehensive, quantitative understanding of the dynamical processes operating in the Earth's plasma and field environment. In order to accomplish this objective, it is thought to be necessary to carry out simultaneous measurements with nearly identical instrumentation at various points in space. These measurements will need to be made in combination with appropriate observations at or near the Earth's surface. Besides near-Earth observations by ground-based, rocket- and balloon-borne instrumentation, satellite investigations are expected to make an important contri bution to the IMS. A number of satellites assigned to magnetospheric research have recently been launched, or will be launched shortly, to be operational during the IMS. The European Space Agency has devoted two of its forthcoming scientific satellites - GEOS and ISEE-B - to magnetospheric and interplanetary research."

(Opening Address of 13th ESLAB Symposium) With GEOS and ISEE occupying a major part of the ESA scientific programme it was clear several years ago that a 'natural' basis for the 1978 ESLAB Annual Symposium would be the early data from these two spacecraft. During the 1976 meeting of the European Geophysical Society in Amsterdam it became apparent to me that a much wider community was interested and that in particular Working Group 2 of COSPAR was considering a GEOS session during its 1978 meeting here in Innsbruck. This was of course as it ought to be because GEOS had been adopted as the reference spacecraft for the International Magnetospheric Study. After some discussions with COSPAR and with the organizers of the STP Symposium which was held here last week we felt that in the interest of customer relations and following good common sense we should give up some of our independence in 1978 and merge our Symposium with COSPAR. I would gratefully acknowledge the co-operation of COSPAR's Working Group 2 chairman and vice-chairman, the active support of the President of COSPAR and the 'gentleman's agreement' with the STP programme committee which arranged that the new ISEE and GEOS results were routed to this Symposium rather than to the STP. I have talked about how we came to have this joint Symposium. Perhaps I should tell you too how we came close to having no Symposium.