Students of No. 3 High School of Shuangluan District make spacecraft models with waste materials under the guidance of a teacher in Chengde, north China's Hebei Province, April 24, 2019. 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. (Xinhua/Wang Liqun)