Thread by @AndrewSErickson

Some context re. reported speed of #NorthKorean #missile:

All #ballistic #missiles are #hypersonic (faster than Mach 5) at some point in their flight. N.Germany’s V-2, deployed Sept. 1944, was hypersonic during its boost phase. Intercontinental ballistic missiles (#ICBMs)… 1/n

https://twitter.com/W7VOA/status/1577102844729053184

…, first deployed by the US in 1959, are high-hypersonic (Mach 25) throughout their entire flight. Subsequent decades have witnessed the emergence of “#hypersonic” #missile systems that can maneuver instead of following a fixed parabolic trajectory, including #ASBMs, #HGVs… 2/n

…and air-breathing supersonic combustion ramjets (#scramjets). The US investigated maneuvering re-entry vehicles in the late 1970s, the #SovietUnion #HGVs in the mid-1980s; both failed. In 1981, the US fielded the #PershingII medium-range #ballistic #missile (#MRBM), whose… 3/n

…whose terminal braking maneuver has been widely attributed to #China’s #DF21D & #DF26B #ASBMs. In April 2010, the US successfully tested the first #HGV, #Falcon #HTV2. The re-started #Russian HGV research & development effort (Project 4202, which would become #Avangard)… 4/n

…appears to have taken a little longer. What is “new” is recent fielding of mature, #hypersonic #missiles w/maneuvering payloads by US adversaries. #Russia has developed #Avangard #HGV & has fielded—or will soon field—#scramjet-powered 3M22 #Zircon hypersonic cruise missile. 5/n

…#China has fielded the aforementioned DF-21D & DF-26B #ASBMs, as well as the #DF17 (likely with the DF-ZF #HGV). All of these systems use speed & maneuverability to greatly complicate defender’s problem. Maneuvering potentially enables approaching from unexpected angles… 6/n

…to strike a moving target on land or sea. Nonparabolic trajectory allows approaching at lower altitude. Tradeoffs include slowing significantly (typically below #Mach 10) to mitigate ionized plasma field that inhibits active radar sensors typically employed to seek targets. 7/n

My book on #PRC #ASBM development offers further history & background (full text PDF here): andrewerickson.com/wp-content/upl…

Keyword-searchable “Bookshelf”: andrewerickson.com/2020/11/the-ch…

#OpenSource @DeptofDefense datapoints: andrewerickson.com/2021/11/the-pe…

What now? >> 19fortyfive.com/2020/11/chinas…

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