Russian President Vladimir Putin announced the missile used in the mysterious strike on Ukraine as the conventionally armed Oreshnik.
In his speech, Putin stated that a new conventionally armed intermediate-range Oreshnik made its combat debut with the recent strike.
Regarding the missile's specifications, he said that it could reach a speed of Mach 10, which is within the hypersonic regime.
According to the BBC, Ukrainian authorities reported seeing six clusters of flashes in the sky, each with six flashes. This report, consistent with the footage, suggests that Oreshnik carries six warheads with six sub-munitions released upon the terminal approach.
Judging by Putin's statements and the Ukrainian authorities' report, Oreshnik might be a development of an existing ballistic missile that carries hypersonic glide vehicles (HGVs) fitted with sub-munitions.
Pentagon Deputy Press Secretary Sabrina Singh stated in a briefing regarding the incident that the missile was based on a Russian RS-26 Rubezh ICBM. Considering the RS-26's diameter of 1.8 meters, multiple glide vehicles are very likely. Russia is among the countries developing HGVs alongside the U.S. and China.
The U.S. recently introduced the Long-Range Hypersonic Weapon using an HGV with a diameter of about 0.88 meters. Russia might have developed a similar-sized one after the Avangard HGV, which is too large to be carried in multiple numbers.
The submunitions could be carrying high-yield explosives like fuel-air compositions, which Russia regularly employs in FAB GPBs to cause widespread damage to settlements.
If six HGVs with sub-munitions were carried by the missile, the design of RS-26 might have been subjected to alterations like a slightly increased diameter. With IRBMs and ICBMs reaching a speed of Mach 10+ (in line with the speed stated by Putin) before the mid-course phase at the upper layers of the atmosphere, the exo-atmospheric stage would be scrapped to open up space for HGVs and the associated communication equipment. Of course, the scrapping of the third stage would reduce the maximum range compared to the parent design.
The flight altitude of HGVs is too high for existing long-range air defence missiles and too low for exo-atmospheric anti-ballistic missiles, so interception of these new weapons is an important topic in the air defence sector.
Some solutions offered include missiles with a very large booster stage and a smaller main missile to ensure maximum acceleration. German Diehl proposed two alternatives under the HYDEF concept: a ramjet-powered missile and an IIR-guided kill vehicle with manoeuvre thrusters.
