Explainer - Hypersonic weapon s ystems: High expectations - By Gabriel Elefteriu and William Freer

F rom a round Mach 10 t he air particles around the v ehicle w ill b egin to ionise and g enerate a plasma l ayer that disrupts incoming o r outgoing communications, the f aster the vehicle travels the t hicker the plasma l ayer becomes. [...] I n a variety of scenarios, the combination of short range fire a nd e xtreme speed would give the enemy only s econds t o react o nce t he i ncoming HCM (or even HGV) is d etected, a nd therefore increasing the p robability of a kill. [...] Nuclear-armed h ypersonic weapons are inherently destabilising at the s trategic l evel, c hiefly because of the d iculty of e ven detecting a nd recognising a nuclear hypersonic first strike before the d efender’s military system has time to f ully react; but a lso b ecause these w eapons – especially in a nuclear c onfiguration aimed at fi xed t argets – are so much more d icult t o intercept. [...] Precision While s pecific d ata o n the accuracy o f existing h ypersonic w eapon s ystems is a closely g uarded s ecret, it can be e xpected that the increased diculties o f manoeuvring a t such high speeds make them l ess a ccurate than a subsonic cruise missile (unless they slow down d uring the terminal p hase). [...] This also means, however, t hat h ypersonic weapons are likely to be m ore a ccurate than standard ballistic missiles (which generally cannot correct their flight p ath i n the terminal p hase – unless the r e-entry vehicles are M aRVs).2 3 The plasma eect means that a hypersonic missile has to s low down close to t he t arget area i n order t o correct its course f or p recision i mpact on m obil.