China is developing a manned submersible capable of reaching depths of more than 10,000 meters. The entrance and observe windows of the ship have recently been opened.

The deep-sea sub is planned to conduct its first test in the Pacific Ocean’s Mariana Trench in 2020, according to its developers.

Because of the huge pressure at those depths, the sphere has to be built with stronger materials than that used to build China’s 4,500-meter and 7,000-meter manned deep-sea subs.

The new submersible will be used for 30 years, so it has to be corrosion resistant, which could be achieved by using titanium alloy, according to its developers.

Scientists will have a hard job, however, because titanium is rarely applied in the industry in China, said Jia Shuaixiao, general manager of Baoji Titanium Industry in northwest China’s Shaanxi province, which is in charge of building the sphere of the submersible.

In addition, different from the traditional way of building a sphere by welding several pieces together, only two hemispheres will be pieced together, making the sphere more solid.

The quality of the sphere is the best in the country and is believed to have a leading position in the world, said its developers.