Roger Gendrin by François du Castel previously vice-director of CNET (Telecom National Research Centre)

I will limit my talk to the period where we were together: –1961 when Roger came in at CNET –1971 when I leaved space research As scientist Roger worked on solar particles, a field where I am incompetent. So I will not talk about the scientist, but about the man I knew

The GRI (Group of Ionospheric Research) After the launch of the first first soviet spoutnik, the director of CNET understood the possible future for telecommunication by satellites He created two departments: –one technical department for learning the space techniques ( Didier Lombard, actual president of France Telecom Orange, was one of its directors) –one scientific department for the study of the space environment But this department was too small compared with the best ones, so the director contacted the CNRS and proposed to accommodate a CNRS lab at CNET with the availability of CNET techniques and means

Then the lab GRI was created with Andre Lebeau at its head The whole became: –a CNET important unity, –a CNRS peculiar lab and, –a CNES selected lab. Roger was one of the first scientist arriving to the GRI where he was pleased to be both scientist and ingeneer. I will present some aspects of his activities The GRI 2 (Group of Ionospheric Research)

Kerguelen Islands Solar particles are driven to the high latitudes by the earth magnetic field So Roger was interested by the geographical position of Kerguelen Islands, in south Indian Ocean He went several times to the Islands to conduct experiments I believe he liked the life in the TAAF (Austral and Antartic French Lands) despite the harsh conditions of living (he was particularly happy with his friend R. Riguet) Anyway Roger obtained interesting scientific results

Conjugated points The incoming solar wind hits the magnetosphere and it is driven along the lines of the earth magnetic field, so it is of interest to observe a same event at both conjugate ends of such a line. It happens that Kerguelen Islands are conjugate with the north of Russia, near Arkhangelsk So Roger has contacted a soviet scientist, Valeria TroÏtskaia, at an international scientific congress By chance she was a remarkable woman, intelligent, open, French and English speaking and particularly able to use the soviet bureaucracy Therefore an experiment was organized both in Kerguelen and North Russia Despite the difficult conditions of life and the presence of the “cold war”, with the permanent support of Roger all experiments were a success

International Congress Roger obtained rapidly an international reputation as scientist and he was many times in charge of reporting at the opening of a scientific session of a Congress But his method of working was particular I remember a meeting in Moscow where we came late at the hotel: –Roger told me he had a report to prepare for the morning session and he spent a large part of the night working with the notes took away from Paris –I was a little anxious on the following morning but Roger gave a very good report appreciated by the audience So was Roger, liking the parties, but never against the science He knew his taste for the feast and he had the courage to stop drinking one month over two!

CNRS Roger was elected, on a trade union list, at the Comité National of CNRS ( the scientific and scientist management Committee of CNRS) in 1966, of which I was the president in the Astronomy and Geophysique Section Belonging to the majority, he approved the work of the Section, particularly when we try to introduce more physical approach in the oldest sectors of our domain still more collecting events than interpreting them Nevertheless, we were around the time of “may 68”,and Roger was less enthusiastic to support the fight of the Section against some “mandarins” in the labs

In 1971, at the end of our mandate, Roger came back to his scientific live in the GRI, and I was called for an other work than space research. So our ways diverged and I didn’t followed more the GRI, except fort some friendly opportunities.

Roger Gendrin From those ten years of proximity with Roger, I keep the souvenir of: –a generous friend –a demanding and formatting scientist –a man happy to live –a good ingeneer –an active citizen in the society Roger Gendrin is one of the rare person who leaves a mark on their way on the earth and stays in the memory