Designed to help in the analysis of dark matter, dark energy, near-Earth asteroids, and more, this device will be immense. It'll have 189 sensors, and weigh more than three tons. Unfortunately, it's not quite approved to build — yet. Now the project begins a detailed engineering design, schedule, and budget phase. If everything goes ahead, it's due to start proper construction in 2014, but work has already begun on its 8.4-meter primary mirror.