Testing on the Cassegrain simulator at the National Astronomical Observatory in Mitaka.

During the development of FOCAS, the required components were constructed at the Astronomical Observatory's research center and at the Nikon factory. They were then integrated and mounted on the Cassegrain simulator set up at the National Astronomical Observatory in Mitaka. Together with the Nikon engineers, we then subjected them to repeated tests of all kinds. This process was completed in 1998. We then had to partially dismantle the instruments and transport them to Hawaii. Since this was the first time that we had ever sent observing instruments like FOCAS from Japan overseas, it took longer to get them through customs than we had imagined. I waited a month in Hawaii for them to arrive (laughs).

We then mounted the instrument on the Cassegrain simulator installed at the Hilo base camp facility^*1 and repeated the same tests that we had carried out at Mitaka once again. The Cassegrain simulator consists of a platform section that emulates the movement of the Subaru Telescope's Cassegrain focus, whose inclination changes in accordance with the orientation of the telescope. It also offers power supply and network connectivity.

The reason for this was that once the equipment was on the summit of Mauna Kea, it would be extremely difficult to repair anything, should there be a problem. In addition, once the instrument was mounted on the Subaru, it would occupy the Cassegrain focus, making it impossible to conduct tests on other observing instruments. Our overall policy in the development of the Subaru Telescope was to try and minimize the amount of work that would be performed at the summit.

We again encased the instrument in special air-tight packing designed to reduce vibration, and gingerly carried them to the summit—taking an entire day to traverse a route that normally requires only two hours. This was because the atmospheric pressure differs between the lowlands and the summit, causing the humidity to change significantly as you pass through the clouds on the way up. On this occasion we were also accompanied by Nikon engineers, who provided us with advice on various issues.

FOCAS headed for the Subaru Telescope after the completion of testing at the Hilo base camp facility.

For this reason, we would make a record of our difficulties and the conditions at the summit, and go back down to the Astronomers' Mid-Level Facility^*2 at Hale Pohaku, which is at an altitude of 2,800 meters. Here, we would discuss matters with everyone, look for ways to solve the problems, and try them out the following day in a continuous process that lasted for approximately two weeks. It was also extremely difficult for us to establish the necessary observation parameters that would enable the use of FOCAS by ordinary researchers who knew nothing about it. During the first stage—known as Engineering First Light—we repeatedly conducted ordinary observations, and developed the observation process, while writing the manual and evaluating the capabilities of FOCAS at the same time.

Afterwards, the developers were awarded “guaranteed time,” in which they could use FOCAS freely as a form of compensation for their efforts; however, this time too was devoted to performing adjustments. From 1999 to 2000, we were conducting operational testing of FOCAS round the clock—including Christmas and New Year (laughs). We finally made it to Scientific First Light—the acquisition of observational data—and we were elated when we finally obtained such a beautifully clear image of M82. This made us want to get the adjustments out of the way as soon as possible and conduct our own observations.