 The 11D33 engine was the world's first staged-combustion-cycle rocket engine, and also the first use of an ullage engine to allow a liquid-fuel rocket engine to start in space.Three successful telemetry sessions were conducted, gathering solar-wind and cosmic-ray data near Earth, at the Earth's Magnetopause, and on February 19 at a distance of .After discovering the solar wind with "Luna 2", "Venera 1" provided the first verification that this plasma was uniformly present in deep space.