Weekly Notes from the Yohkoh Soft X-Ray Telescope

(Week 31, 2002)

Science Nugget: August 2, 2002

A new word in the English vocabulary?


The operation of the Yohkoh satellite required a lot of volunteer manpower. This meant a weekly rotation among "tohbans": volunteer duty officers recruited from all around Japan, and since Yohkoh was an international mission, from all around the (solar) world, really. At its peak of activity Yohkoh required no less than six tohbans at once. Two went to the Kagoshima Space Center for two-week stints; two stayed at the ISAS home campus. These operated the spacecraft itself, with professional help. Two others became the scientific operators of the Soft X-Ray Telescope (SXT), which has produced so many of the images in these science nuggets over the years. The tohbans routinely created the hexadecimal commands that maneuvered the spacecraft, and in later years the SXT tohbans became "Chief Observers" and stopped participating in absolutely every contact pass. For those unfamiliar with spacecraft operations, there is no time constraint other than celestial mechanics. That meant, in practice, that it would be 3:00 a.m., cold, and raining, whenever Yohkoh wanted to make an appearance.

Neologism and etymology

The interesting thing about the introductory paragraph above is the word "tohban". This has now become a part of the life of the RHESSI mission, which has nothing at all to do with Japan. A regular rotation of RHESSI scientists, mainly UC Berkeley people but already with volunteers from France and Scotland and of course the RHESSI group at NASA Goddard Space Flight Center, takes turns week by week in helping to optimize the RHESSI science. These people are called "tohbans". It will be interesting to see if this word finds a permanent home in English, along with all kinds of other foreign but useful imports.

So, what is a "tohban" really? In Japanese, the word consists of two Chinese characters. TOU is the second character of BENTOU, which means "box lunch"; BAN is the second character of ICHIBAN, which means "number one". Many Americans know this already, especially in the context of sushi; a bentou also can contain sushi (vinegary rice with things), so maybe "tohban" has something to do with appetite.

bentou ichiban

Loosely translated, this means "This week's picnic lunch - the best!" and it also suggests that the box lunch consists of a patriotic tray of rice with a single pickled plum. In any case, just take the right-hand characters in the two boxes and, eh voila, you have "tohban".

The future

Yohkoh no longer is returning data, alas, but RHESSI is, and the use of the word "tohban" reflects how much we owe to Yohkoh's great achievements. But the future is now, and there is already a home page for the RHESSI tohbans - maybe not quite ready for prime time, but already readable.

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August 2, 2002

Hugh Hudson (hudson@lmsal.com).