BEIJING, April 26 (China Space News)  -- Chinese President Xi Jinping wrote back on Thursday to the elder scientists who participated in the Dongfanghong-1 mission, as the 50th anniversary of the successful launch of the country's first man-made satellite approached.

Xi, also general secretary of the Communist Party of China Central Committee and chairman of the Central Military Commission, extended sincere greetings to them in the letter, adding that he expected the aerospace workers to speed up the construction of a powerful space industry.

The anniversary falls on April 24, which is also the fifth Space Day of China.

In the letter, Xi said he is deeply moved that the participants of the Dongfanghong-1 mission have devoted their youth to the space cause and still care about the future of China's aerospace industry in their old age.

He said he was very excited to get the news that the Dongfanghong-1 satellite was successfully launched 50 years ago when he was in Liangjiahe, a village in northern Shaanxi Province, northwest China.

The extraordinary achievements created by the scientists and space engineers through hard work made the people of all ethnic groups proud of and demonstrated the self-improvement spirit of the Chinese nation, he said.

Xi pointed out that no matter how the conditions change, the spirit of self-reliance and hard work should not be lost. In the new era, workers in the aerospace sector should follow the example set by the elder scientists to bravely overcome difficulties and obstacles to further develop space science and technology.

After years of unremitting efforts, China successfully launched its first manmade satellite Dongfanghong-1 on April 24, 1970, marking the beginning of the nation's exploration of the universe and its peaceful use of outer space. Since 2016, China has set April 24 as the country's Space Day.

Recently, 11 elder scientists who participated in the Dongfanghong-1 mission, including Sun Jiadong, Wang Xiji and Qi Faren, wrote a letter to Xi, reviewing the history of China's space development and expressing their confidence in realizing the Chinese Dream of national rejuvenation as well as the country's space dream.