BEIJING, April 25 (China Space News) -- Wednesday marks China's fourth annual Space Day. The theme of this year's event is "pursuing space dreams for win-win cooperation". Domestic and international experts have gathered in Changsha city of Hunan province to discuss space technology and seek future collaboration.

Since 2016, China has set April 24 as the country's Space Day. The various activities on Space Day have become a window for the Chinese public and the world to get a better understanding of China's aerospace progress.

The day of April 24 was chosen as it marks the day in 1970 when China successfully launched its first satellite, Dongfanghong-1.