...In theory, the air-breathing engine could take a flight up to 16 times the speed of sound, butthe only wind tunnel on Earth capable of simulating such flight is still underconstruction in Beijing, according to the Beijing-based researcher....
配備超音速燃燒衝壓發動機在臨近太空中,理論上的確係可以到達最高16倍音速嘅!在大氣層內就很難啦....