The second launch of the Chinese Long March 5 super-heavy launch vehicle has ended in failure after an anomaly apparently associated with the upper stage. The mission was carrying an experimental communications satellite called SHI JIAN 18. The launch took place from the Wenchang launch site on Hainan Island at 1123 GMT on 2 July 2017. The payload failed to achieve orbital velocity and re-entered.
While the upper stage has been cited as the cause of the failure, a propellant or pressurant leak was sighted at T plus 347s with one of the core’s YF-77 engine pair noted as burning for longer than the other one.