For those that don't know the TMT is an ambitious scaling up of the Keck design that would have a primary mirror 30 meters across consisting of 492 segments. That would give it nine times the light-gathering power of one of the existing Keck telescopes, allowing for the deepest, highest resolution studies ever performed with visible and near infrared light. Compared to the Hubble Space Telescope, TMT will have 144 times the light collecting area and more 10 times the resolving power.
An artist's concept of the Thirty Meter Telescope
The hurdle to building the colossal telescope was that the Hawaiian state Board of Land and Natural Resources unanimously granted approval to place the telescope in the location that its builders most want to put it, atop Mauna Kea. In addition to being one of the best astronomical sites in the world, Mauna Kea is also sacred ground for many native Hawaiians, some of which oppose the project. To help give them the proper voice, the board also granted the opposition voice one last hearing on the issue. The final outcome will not likely be decided until mid summer.