Mach 5

摘要

Hypersonic-speed weapons that can manoeuvre within Earth's atmosphere - referred to by the Pentagon simply as 'hypersonics' - are likely to be fielded soon as a new niche capability, but their high cost and unique mission set may limit their ultimate proliferation. Hypersonics and defences against them were named the highest development priority in 2018 by the US Department of Defense's (DoD's) then undersecretary of defence for research and engineering, Michael Griffin. China and Russia are known to be developing hypersonic-speed weapons, such as hypersonic glide vehicles, meant to be capable of covering significant ranges within a short period of time. A hypersonic weapon would reach speeds between Mach 5 and Mach 10. Chinese and Russian programmes are understood to include conventional and nuclear-armed 'hypersonic' weapons, although the term hypersonic is often applied differently outside the United States.