On October 4,1957,the USSR launched the world's first satellite Sputnik 1, weighing 83.6 kg . On February 1,1958, the US launched the world's second satellite Explorer 1, weighing only 8.2 kg . And on April 24,1970, China launched her first satellite Dongfanghong 1, weighing 173 kg . On April 24,1961, the Soviet Yuri Gagarin became the world's first man in space. In 1962, John Glenn became the first American to orbit Earth. And on July 20,1969,Neil Armstrong became the world's first man to walk on the moon.

China sent Shenzhou-5 on October 15, 2003. Conditions for life in Shenzhou-5 are about the same as on earth, a senior expert told Xinhua Wednesday. The spacecraft comprises three main parts: the propulsion module, orbital module and re-entry module. The orbital and re-entry modules, both airtight, are where the astronaut lives and works during his space journey. While in space, however, he works, eats and sleeps in the orbital module, according to Su Shuangning, a chief designer for the astronaut system under China's space flight program. "The onboard life support system creates an intra-module environment about the same as on earth," the expert said. Elaborating, he said that the astronaut system is fitted with sub-systems for air pressure, ventilation, sterilization, temperature and humidity. These ensure normal temperature, moisture and air pressure, including the pressure of oxygen and carbon dioxide, inside the two modules.