The National Ignition Facility is the largest and most energetic laser facility ever built. NIF is the size of a sports stadium—three football fields could fit inside. NIF is also the most precise and reproducible laser as well as the world’s largest optical instrument. The giant laser has nearly 40,000 optics that precisely guide, reflect, amplify, and focus 192 laser beams onto a fusion target about the size of a pencil eraser. NIF became operational in March 2009.