FIRST@LICK: Mounting of the prototype
As I mentioned previously, the FIRST fibered-imager prototype was rebuilt and tested successfully in the lab at Lick Observatory. On July 22, we were therefore ready to mount it on the top of the adaptive optics of the Shane-3m telescope.The first time installation of an instrument like FIRST is not trivial. Since November 2009, I have been interacting with the Lick Observatory and the Observatoire de Paris to find out how we could install FIRST without modifying the current design of the adaptive optics (AO) system. Indeed, the AO system is a UCO/Lick instrument and FIRST is only a visitor instrument, consequently FIRST should be mountable and removable without perturbing the regular schedule of the telescope. The solution that we envisioned was to design FIRST on an independent optical bench that will be mounted when needed on the “top” of the AO bench after removing the IRCAL camera.
In fact the AO table is not horizontal like most of the table I have seen on telescope. This particularity complicated significantly the installation of FIRST, since the 150 kg- table had to be mounted on the side of the AO table. To be honest, it is only on July 22 that the technical team of the Lick observatory came out with a realistic solution.
We decided to move FIRST manually from the lab to the 3m-dome forklift, carefully lift it on the platform of the dome, tilt by 15 degrees the telescope toward the north, and move the platform near the Cassegrain. Ut is only at the last stage that FIRST will be carried, tilted, and manually attached to the AO feet designed by the observatoire de Paris. This simple scenario took in reality more than 7h to be fully executed…
At 11am, after dismounting the bottom of the AO system, we found out that a mysterious piece of metal that nobody had seen before was partially on the way the the large FIRST table. After lengthy discussion it was decided that the FIRST optical table had to be slightly cut to fit on the telescope. This was a major concern for the Observatoire de Paris team since they spent days aligning the instrument and there was no way the alignments will remain intact after such drastic operation. It was a risky task since the vibrations and chips of metal could damage the fragile optics.
After solving this unexpected problem, at 1:30pm we were ready to move the FIRST table to the dome and install it on the telescope. To show you how we proceeded, I am attaching below a link to a speed up video that I downloaded on VIMEO (it should be ready at midnight PDT). We finalized the installation and released the telescope for the normal schedule just on time at 7:15pm. It was a long and stressful day but we were glad to have successfully done this risky part of the project.