Meteorology, Meteorological, History

An IGO
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weather and
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HISTORY OF EUMETSAT, p68.

HISTORY OF EUMETSAT, p66.

p67

an understanding of this approach to satellite stabilisation.

Meteorologists were not averse to the technology because, despite its novelty, there were seductive advantages. More sophisticated instrumentation, such as sounders, could be mounted on a three-axis stabilised satellite, and infrared and microwave sounders for temperature and humidity sounding respectively had been on the wish list of many meteorologists since before the Avignon meeting in 1984.

After working together for several months on the pre-Phase-A studies of MSG, ESA and EUMETSAT arranged to evaluate the baseline concept during a meeting in Bath, UK, in May 1988. Their aim was to establish a common technical position for the Phase-A studies that were scheduled to begin toward the end of 1988. At this point in time, the first half of 1988, the two organisations were still aiming for a launch in 1995.

By the time of the Bath meeting the satellite as conceived was some 15 overweight(fifteen per cent - insertion by site editor, Helen Gavaghan). At such an early stage in satellite development, this is not disastrous or unusual. Nevertheless, it was clear that the satellite would have to weigh less because the plan was for each of the series to share a launch aboard Ariane-4 with another satellite. If the satellites of the MSG series were to exceed half of Ariane-4's lift capacity, each of the new series would have to be the sole passenger and the launch price would go up by more than 20 MECU per satellite. In an effort to reduce the satellites' weight, participants at the Bath meeting hammered out a number of technical compromises. These retained the imager and sounders but reduced their technical capability. ESA was also looking at ways to reduce the weight of the satellite itself, and thought that when all the weight savings were combined, the satellite would be light enough for a dual launch on Ariane-4. ESA, therefore, believed the baseline concept could be retained.

EUMETSATs Scientific and Technical Group (STG) was more cautious. After evaluating the outcome of the Bath meeting, they recommended studying alternative low cost concepts in case ESA's Phase-A studies showed that the Bath scenario had not saved enough weight. In particular, they suggested evaluating a radiometer that could combine both imaging and some temperature sounding (both sounders and imagers detect upwelling radiation and so both are radiometers). ESA suspended work pending a response from EUMETSATs Council.

The next Council meeting (the eighth) was a few weeks later in June 1988. The ESA observer told delegates that the Agency was not prepared to spend the 3 Million Accounting Units (MAU) needed to study Phase-A if EUMETSAT did not strongly endorse the concept agreed in Bath. The Council weighed its options. During the same meeting the Director had submitted a report on future programmes that showed costs in excess of one billion ECU for a combined system of geostationary and polar orbiting satellites. Though not unusual in the space business, these were seriously large numbers for the National Meteorological Services.

The UK delegate argued that if the two types of satellites were to be considered as elements in the same system, then the imaging and sounding mission could be split between them. Sounding should have priority on polar orbiting satellites and imaging on geostationary. In this way the

SEE ALSO| |

1. Meteorologists shed political shackles, a review of Declan Murphy's history of the first 25 years of EUMETSAT (2011), by Helen Gavaghan.

2. An interview in 2010 with Dr Tillman Mohr, a special advisor to the secretary general of the World Meteorological Organisation, in Science, People & Politics.

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Contents

Preface

Foreword

Introduction

Ch.1

Ch.2

Ch.3

Ch.4

Ch.5

Ch.6

Ch.7

Ch.8

The History of EUMETSAT is available in English and French from EUMETSAT©.
First printed 2001. ISBN 92-9110-040-4

Eumetsat meteorology meteorological artificial satellites
European Space Agency weather climate policy politics history