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A new voyage for Jason

Michel Lefebvre (JGOOS, France), TOPEX/POSEIDON project scientist, 1987-1995

A satellite called Jason 1 which should be the first in a series, has been decided by the French space agency (CNES) and the National Aeronautics and Space Administration (NASA) as a follow-on to TOPEX/POSEIDON. Jason 1 is to be launched at the end of 1999. Why the new name?
How did we choose it? What is the link with Jason and the Argonauts? Please read on. . 

Why a new name?

Unlike the name TOPEX/POSEIDON, which is often unfortunately shortened to TOPEX and therefore reflects only one side of the bilateral cooperation programme, Jason is a single word.
A more important advantage is that with Jason we are embarking on an era of operational satellite altimetry, due to last for 15-20 years. This is in contrast with TOPEX/POSEIDON which, as the EX in its name suggests, is experimental. Jason will bring the best of T/P, i.e. the TOPEX class, but with cost, weight and power divided by four.

How we chose the new name

These things are always hard to agree on. In the past, the Science Working Team (SWT) tried and failed many times to re-christen TOPEX/ POSEIDON. NASA's William Patzert was the first to come up with the idea of Proteus, a son of POSEIDON who could change shape and predict the future. CNES gave the name Proteus to a multi-mission bus under development at that time and now to be the bus for Jason.

William and I sent our ideas to each other, based on discussions with peers and studying mythology, fiction, astronomy, the media, the novels of Jules Verne, and so on. This lively exchange lasted several months. Several names came up, but none seemed quite right. However, we decided that the name had to be short, and easy to pronounce in both English and French. It had to be useable by the project teams and others for 15 to 20 years!

Mythology is always a useful source of ideas, but many of the names had already been used. So we tried allusions to oceanography, as well as to the purpose of the mission, with keywords such as Altimetry, Ocean, Topography, Satellite, Sea level, Sea state, Series, Long duration, Lifetime, Accuracy, and so on.

We short-listed some names. The name Triton - a god of the sea - was relevant to both mythology and the ocean, and was initially at the top of the list. But triton is a common noun in both English and French, a small marsh-dwelling shellfish. The triton is a similar species to the shellfish taken on board the MIR station by French cosmonaut Claudie Andre Deshays.
The Japanese are also currently conducting a major ocean observation programme called TRITON.

The second name on our list was SALTO, easy to pronounce and to remember, as it corresponds to Satellite ALtimetry and Topography of the Oceans. But the name for the new satellite did not have to be an acronym, and we decided against SALTO. The next on the list was Jason, which we had already discus-sed several times.

Choosing the name was like the classic case of a newborn child:
each parent has views on what to call Baby, but once it is born and the time comes to register the birth, they realise they want the same name. This is what happened with CNES and NASA, which quickly agreed on Jason while signing the memorandum of understanding that "gave birth" to the new programme.

About Jason

The lineage of the name TOPEX/ POSEIDON begins with the JASO1 meeting (JASO = Journées Altimétriques Satellitaires pour l'Océanographie) in Toulouse, France to study the problems of assimilating altimeter data in models (Oceanologica Acta, special issue, October 1992). The following SWT meetings were renamed JASO2 and JASO3, to highlight the importance of data assimilation.

But Jason was also leader of the celebrated quest by the Argonauts to recover the Golden Fleece, guarded by a dragon at Colchis on the Black Sea. Jason picked fifty brave volunteers. Many are still known today, such as Hercules; Tiphys, the first helmsman, later replaced by the famous navigator Nauplius; the singer Orpheus; Castor and Pollux; and Atalanta, the only woman. The epic account of the voyage is recounted in many works, including the popular Voyage of Argo by Appollonius of Rhodes, available as a Penguin paperback. After many years of effort sailing the Mediterranean, Jason and the Argonauts recovered the Golden Fleece.

There are many matching aspects in our project. Like the Argonauts, we have different temperaments, and different cultures and skills. But our objectives are just as ambitious: measuring sea level to within a centimetre is as difficult as the quest for the Golden Fleece.

The Argonauts did not simply have a common objective; they were also sailing on the same vessel. The Argo, the first ship ever built, could immediately (in real time!) voice the state of the sea to the crew. The Jason satellite(s) will be our ship, and we too want to forecast sea state in real time.
The analogy goes further: while the Argonauts sometimes had to carry the ship on their shoulders, we too have to shoulder the burden of our project in times of financial or technical difficulties.

Jason is said to be an unconventional hero. But he is one of the best-known. He had brains, abundant charm and, above all, the gift of persuasion. The narrator tells us that Jason was a man who got things done for him. Today we would say he would make a good project leader.

Perhaps you think the voyage of the Argonauts was purely a myth.
But Isaac Newton thought it was true, and made the date of the voyage a point of reference for his New System of Chronology. He used the description of the celestial sphere given by the ancient astronomers to the Argonauts, and compared it with that of his own period. Newton felt that the differences in position were due to Hipparchus calculation of precession, which he estimated more accurately. Newton claimed he had determined the date of the voyage to within 30 years.

We can all become involved in the adventure: remember that many of the famous Argonauts were only rowmen.

If you would like a Jason acronym, it also stands for "Joint Altimetry Satellite Oceanography Network". "Network" takes on its full meaning if you consider that we eventually intend to set up a network of altimeter satellites.

All civilisations need myths, and these need to show success. The voyage of the Argonauts has both elements. The same will be true of Jason, which will bring the two driving forces behind satellite programmes: the quest for knowledge and the conquest of applications.

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