Today, 26 years ago, on February 4, 1999 (Calendar, December 19, 1998), Russia launched a "artificial moon" into space. On February 4, 1999, Russia launched a "artificial moon". On February 4, 1999, the Russian cargo ship Progress M-40 carried a reflective mirror into space, conducting a sunlight reflection experiment code-named "Flag 2¡¤5" (also known as "Flame 2¡¤5") under the control of the two astronauts Padarkal and Afzheyev on Peace Space Station. According to the foreseeable, the lens will quickly unfold under the action of a centrifugal force, forming a 25 meter diameter reflective night mirror (each lens is made of a special aluminum film), under the control of the two astronauts Padarkal and Afzheev on Peace Space Station,