CAPE CANAVERAL, Fla. - Nine Merlin engines ignite under the first-stage of the SpaceX Falcon 9 rocket at Space Launch Complex 40 on Cape Canaveral Air Force Station in Florida, starting the Dragon resupply capsule on its way to the International Space Station on the SpaceX-3 mission. Launch was during an instantaneous window at 3:25 p.m. EDT. Dragon is making its fourth trip to the space station. The SpaceX-3 mission, carrying almost 2.5 tons of supplies, technology and science experiments, is the third of 12 flights through a $1.6 billion NASA Commercial Resupply Services contract. Dragon's cargo will support more than 150 experiments that will be conducted during the station's Expeditions 39 and 40.