This comes after the agency disclosed plans last year to test an unspecified
version of the SM-6 against an advanced maneuvering threat, a term typically
associated with unpowered hypersonic boost glide vehicles, sometime in the
2024 fiscal year.
MDA is leading an effort to develop a layered defense architecture against
hypersonic threats that includes an array of terrestrial and space-based
sensors and multiple types of interceptors, as you can read more about
here.
The SM-6 series is really the nation's only hypersonic defense capability.
Hill said, without specifying any particular version of this missile.
He added that these weapons have a nascent capability to engage incoming
hypersonic threats that are maneuvering to a high degree.
"We didn't call it that back when we got the letter from the CNO (Chief
of Naval Operations) the navy's top uniformed officer to go develop this
program," he explained.
"But the whole idea was to handle high-speed maneuver," he added
hill's comments are immediately interesting for a number of reasons.
Currently there are two variants of the SM-6 in service, the block I and
block IA, while a third version, the block IB is under development.
The block IB missile is substantially different from the two earlier
types, including its completely redesigned body and a larger rocket
motor. It is expected to be able to reach hypersonic speed itself and
therefore have greater capabilities against hypersonic threats.
The block I and block IA missiles are generally described as surface to
air missiles though they also have a surface to surface strike
capability.
In addition, they do have missile defense capabilities but which are
more typically described as the ability to engage incoming cruise
missiles, as well as more traditional ballistic missiles or separate
re-entry vehicles they release in the terminal phase of flight.
It is important to note that those targets are traveling at hypersonic
speeds at that point, but that even advanced maneuvering types would not
be as nimble as a purpose-built hypersonic boost glide vehicle.
In addition, boost glide vehicles travel along an atmospheric trajectory
compared to more conventional ballistic threats, which also makes them
more difficult to spot and track.
What Hill appears to have disclosed now is that the block I and IA
missiles already have at least some degree of capability against these
more maneuverable hypersonic threats or were at least designed with that
capability in mind from the outset.
It is possible that only some SM-6s currently in service have this
particular ability as well, which might be the product of post-delivery
modifications.
Beyond that, the envelope in which an existing sm-6 is able to
engage hypersonic threats could easily still be very small and the
missile might only be effective at all against certain specific types of
targets.
The US Navy fired a pair of what have been referred to as SM-6 Dual IIs,
a ballistic missile defense optimized sub-variant of either the block I
or block IA during an MDA-led test last year. Those interceptors failed
to knock down a surrogate for a traditional medium-range ballistic
missile.
All told whatever capability existing SM-6s might have against
hypersonic threats would still appear to be limited.
MDA is actively pursuing a new interceptor optimized against things like
boost glide vehicles as part of the Glide Phase Interceptor (GPI)
program.
In november 2021 raytheon Lockheed Martin and Northrop Grumman received
contracts to build competing gpi designs raytheon is the prime
contractor behind the SM-6 series.
