KOUROU, French Guiana - A lightweight rocket aimed at securing Europe a stake in the market to launch small satellites lifted off from Kourou space base on its maiden flight on Monday. Vega, whose development has cost more than a billion dollars, raced into the sky from the launch site in French Guiana in a streak of light, carrying a test payload of nine satellites, mission controllers reported. The 81-minute mission is a “qualification” flight, aimed at proving a rocket that incorporates several important innovations, engineers said. “The trajectory is normal,” flight supervisor Aimee Cippe said after the first three stages, driven by solid fuel, separated on schedule and the final stage, which uses liquid propellant, ignited as expected.