//Hearing Update 1/3 – Dr Gary Sanders TMT Project Manager

1/3 – Dr Gary Sanders TMT Project Manager

The contested case hearings resumed in Hilo today with the project manager for the planned Thirty Meter Telescope taking the witness stand.

Gary Sanders, who is responsible for managing the design and construction of the Thirty Meter Telescope, has been with the TMT Corporation since 2004. He has also been with the TMT International Observatory (TIO) since its formation in 2014, when the telescope’s global partners joined the organization.

Sanders previously worked at the Los Alamos National Laboratory from 1978 to 1994 and was Project Manager and Deputy Director of the Laser Interferometer Gravitational Wave Observatory at the California Institute of Technology from 1994 to 2004.

Sanders opened his testimony with design changes made to the planned TMT to minimize visual impacts on Maunakea.

Several design efforts were implemented to reduce the telescope’s exterior dome and overall size to lessen the visual impact of the telescope. The protective exterior dome is meant to shelter the telescope from the elements and keep the telescope steady during high winds along the mountain, Sanders explained.

Sanders said if the same design used for the existing Keck Observatory 10-meter telescopes was applied to TMT, the Thirty Meter Telescope would have been much taller and wider than what is currently planned (see hyperlink below to Figure 5, “Visual Impact Mitigation on page 20 of Sanders’ written testimony).

Using this same ratio, he explained the Thirty Meter Telescope would have been 60 percent larger than its current proposed design, which would have made it closer to being 256 feet tall instead of its planned 180 feet in height.

Based on those initial projections, “we thought that was a very large design so we reduced the size of the telescope, as well as the dome,” Sanders said during oral testimony. “Our goal was, and still is, to reduce the telescope footprint as much as possible.”

One part of the TMT design is to build a telescope with a shorter height and focal ratio (f/1.0) to allow the smallest dome possible, he said. This is in comparison to the Keck telescopes’ focal ratio of f/1.75.

The design was also adapted to create minimal space — only 20 inches — between the planned telescope and exterior dome. This will allow just enough space to fit a person for maintenance work while still reducing the dome size.

During his testimony, Sanders stated that there are no plans by TMT to expand the facility beyond its designated five-acre site on Maunakea.

Because of his expertise on the construction project, cross examination of Sanders by the other hearing parties is expected to continue tomorrow. Tomorrow’s blog will go over construction and maintenance mitigation efforts of the planned telescope.

Two more hearings are scheduled this week at the Grand Naniloa Hotel tomorrow and Thursday.