On May 1st, the reporter learned from the National Space Administration that, after comprehensive analysis and decision-making by the Engineering Mission Command, the fourth phase of the lunar exploration project, Chang'e-6, is scheduled to be launched on May 3rd. At present, preparations for the mission are steadily progressing at the Wenchang Space Launch Site in China, and the Long March 5 Yao-8 carrier rocket, which is carrying out this launch, is about to be refueled with propellant. This is the second lunar exploration project launch mission of the Long March 5 carrier rocket, which will transport the Chang'e-6 probe to the Earth Moon transfer orbit to carry out the lunar backside sampling and return mission. The launch window refers to the time range suitable for rocket launch. On the basis of comprehensive consideration of factors such as the position relationship between the Earth and the Moon, the engineering team applied the "narrow window multi orbit" launch technology to design a total of 10 lunar orbits for the rocket within a continuous window of 50 minutes per day for two days. (Lai Xin She)