ESA looks to its future in space science

these plates to the required accuracies of a few centimetres. Such a satellite, an example of one possible future ESA Earth observation satellite (whose scenario assumes a launch around the end of this decade), would contribute strongly to European and world efforts to determine ways to predict earthquakes. It would not only provide basic understanding on how the Earth’s plates move but also determine the local motions of the fragmented regions in earthquake areas before, during and after their occurrence. Preliminary studies are also being conducted, for example, in determining how to monitor those global aspects of the atmosphere and climate “engine” affecting our habitation on the Earth, e.g. airborne pollution, its concentration, distribution, movement and fall-out; the gradual changes in the heat content of the atmosphere and oceans due to imperfect balance between incoming solar heating and the outgoing Earth’s radiation of heat. Such studies will help define future Earth observation satellite missions for the Agency’s launches during the next decade.

25. ESA LOOKS TO ITS FUTURE IN SPACE SCIENCEi4’ On 16 December 1982 the ESA scientific advisory bodies recommended that five of the 20 new scientific mission proposals recently received be further assessed with a view to considering them as possible candidate missions in the Agency’s Scientific Programme, for the late 1980’s and early 1990’s. Different groups of experts evaluated the quality of the science and the anticipated scientific return to be expected from each mission, the suitability and technical feasibility of the instrumentation it is proposed to use to achieve the scientific objectives, the interest the proposal is likely to arouse throughout the scientific community at large, the relationship of the proposals with national or international programmes, past, present or future, and finally, the possibility of carrying out the mission as a collaborative venture with other agencies. Taking the above into consideration, ESA has decided that the following five proposals should be further evahrated: FIRST (a far infra-red and sub-millimetre space telescope) for the study of the galactic, extra-galactic and cosmological emission at far infra-red and submillimetre wavelengths. The planned payload mass will be somewhere in the region of 2000 kg and the main instrument an 8 m deployable telescope. XMM (X-ray multi-mirror), designed to carry out deep X-ray surveys of galaxies and clusters as well as high-resolution X-ray imaging and spectroscopy. The payload, with a mass of some 2750 kg, consists of a cluster of 27 grazing incidence imaging telescopes. “‘ESA News Release Information

No. 38 of 20 December 1982.

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SOHO (Solar High-Resolution Observatory) for the investigation of the dynamics and of the mass loss of the solar outer atmosphere. The payload, with a mass-of about 470 kg, ~111include among others a grazing incidence spectrometer, a stigmatic normal incidence spectrometer, EUV imaging telescopes and a UV and white light coronagraph. Cluster an earth magnetosphere mission for a study in three dimensions of plasma turbulence and small-scale structure in the magnetosphere. This mission requires a main spacecraft with a payload mass of 56 kg, plus three companion spacecraft, each with a payload of about 22 kg. This cluster of four satellites is carefully controlled in position as it passes through the many different regions of plasma surrounding the earth. AGORA (Asteroid gravity, optical and radar analysis), designed to study the properties of three main belt asteroids, e.g. regolith thickness, shape (and thus volume), mineralogy, topography and mass. This mission has a model payload of between 100 and 230 kg consisting of a wide-angle camera, an infra-red spectrometer, a radar altimeter and a number of experiments for cruise science; a highresolution camera could also be included. Besides making specific recommendations for the five proposals described above, ESA’s scientific advisory bodies, prompted by the mission proposal for a VLBI (Very Long Baseline Interferometry) radio astronomy observatory in space (QUASAT), also recommended that the Executive initiate discussions with other agencies concerning the feasibility of setting up an international VLBI space system for radio astronomy. In connection with a proposal for a Saturn Orbiter and Titan probe, christened CASSINI, they felt the Executive should initiate negotiations with NASA in order to determine a procedure which could lead to a co-operative approach to such missions. The advisors, whilst examining one of the proposals (FLUTB-TRIO) noted the very high scientific return which could be expected from optical interferometry in space. However, in view of the difficulties such a mission presents, they requested the Executive to identify the technical problem areas and to address them within the framework of the ESA technological research programme. A preliminary cost analysis of the five proposals recommended for further assessment indicates that the average cost per mission is about 250 MAW) i.e. 2.5 times the level of ESA’s annual scientific budget. In view of the very high cost of scientific projects nowadays, ESA will only be able to undertake a new one once every 2% years unless its scientific budget is increased. ‘5’MAU = Million Accounting 44

Units,

1AU = US $1.065 at 1982 exchange rates.