Solid Fuel Ramjet HARM

Well, it's beginning to look like the west is finally catching up to the former Soviet Union in solid fuel ramjet technology, with the British working on their Meteor, and the US looking at adding the technology to the HARM anti-radiation missile (it homes in on SAM radars).

Note that the Soviets had fielded the SA-6 "Gainful" with this technology starting in the late 1960s, and had been sufficiently confident in the technology that it was extensively exported to Egypt and Syria in time for the Yom Kippur War in 1973.

The picture is of a test launch of a missile with an AGM-88E HARM guidance system and a integral rocket ramjet (IRR) propulsion system launched at White Sands in August.

What is in advance of the system deployed by the Soviets in the late 1960s is that the booster does not have a separate nozzle, and the thrust can be throttled, which would allow the missile to loiter in the area waiting for an emitter to switch on.