Michel Lefebvre passed away on July 21st, 2019. Captain of the merchant navy, astronomer, geodesist, driving force, inspiring person, human being and literary man, he has been and was all that and more.

He was one of the pioneer of satellite radar altimetry, promoting the French project "Poséidon", and collaborating with the US "TOPEX" project in the 1980s to merge them into 'Topex/Poseidon'. He was instrumental in the success of the mission, of the collaboration between the countries, but also of the collaboration between engineers, scientists and end-users of the data.

This success continued, is continuing and will continue with Jason-1, 2, 3 and soon -CS, but also with the other satellite altimetry missions, including SWOT. He also launched Aviso with Topex/Poseidon, to put into music the ocean data <link internal-link>as he wrote in the first Aviso Newsletter.
Even after retiring, he kept an eye and an interest on the altimetry and operational oceanography fields and new developments, often contacting people to have news of the satellites and of the different research and uses done with the data.
His friends and co-workers remember him with respect and admiration. He will be missed by all.