China's crewed spaceship Shenzhou-14 was launched on Sunday. The external window panes of the spaceship have to withstand the extreme environment of outer space.
They were formed by 80 special pieces of glass developed by a Qinhuangdao-based manufacturer, in north China's Hebei province.
Made of quartz, the glasses have to go through dozens of processes before becoming special glasses used in space.
According to the manufacturer, the glasses need to withstand the high temperature of 1,000 degrees Celcius, drastic temperature fluctuations and endure large doses of radiation while maintaining more than 95 percent of visible-light transmittance.
China's crewed spaceship Shenzhou-14 launched on Sunday sent three astronauts to its space station combination for a six-month mission.
