Conditions for launching spacecraft

The air transparency is good, there are many sunny days, and the terrain is open, which is conducive to tracking and observation.

In addition to clear regulations on weather conditions for the launch sites of artificial satellites and spacecrafts (that is, they must be in places with sunny weather), they also have requirements for the latitude of the launch sites. Lower latitudes can use the speed and energy of the earth's rotation. The initial velocity generated by the earth's rotation is very large, which can give greater kinetic energy to artificial satellites and spacecrafts to be launched, thereby reducing the mass of fuel carried during launch. , which can save the fuel cost of launching artificial celestial bodies. For example, Shenzhou 5 and Shenzhou 6 have been launched from Jiuquan. Why did the Xichang base be chosen for the launch of the lunar probe? This is due to geographical considerations, as the lower the latitude, the better (lower latitude is good for saving fuel). At present, among the three satellite launch sites in our country, only the Xichang Satellite Launch Center has the lowest latitude, so the lunar exploration launch is scheduled to be in Xichang. In addition, the Chang-3 rocket was chosen for the launch of the lunar probe. The launch platform in Xichang has always been used to launch Chang-3 rockets, which is also conducive to ensuring the stability of the technology.