China has tested its largest solid-fuel motor that will be used in heavy space rockets for future deep space missions. Chinese engineers have completed the test ignition of its largest solid-fuel rocket motor in the northwest city of Xian yesterday, state-run China Radio International reported. With a diameter of three meters, the solid-fuel rocket motor ran for 100 seconds after ignition. The successfully tested technologies will be used in heavy-lift and large rockets for China's deep-space explorations and manned moon-landings. Solid-fuel rocket engines have a much larger capacity than liquid-fuelled iterations. The motor is test ahead of China's plans to launch its largest carrier rocket, the Long March-5, later this year.