Today, 54 years ago, on March 3, 1971 (February 7, 1971), China's first scientific experimental satellite "Practice One" was successfully launched. On March 3, 1971, under the inspiration of Mao Zedong's "We should also engage in artificial satellites", China successfully launched a scientific experimental artificial Earth satellite. The satellite weighs 221 kilograms. Its orbit is 266 kilometers from the Earth's nearest point, the most distant point is 1826 kilometers, the orbital plane and the Earth's equatorial plane are 69.9 degrees, and it takes 106 minutes to orbit the Earth a week. It has successfully returned scientific experimental data to the ground with the frequencies of 20009 MHz and 19995 MHz, and the satellite has been equipped with cosmic