As more information arrives on the S-500 system, it is obvious that the Russians have great ambitions for this system. On its own it will fulfill the functions of medium, long, very long range, anti-ballistic missile and probably anti-satellite systems. In fact, it will cover, on its own, the functions provided in the West by the PATRIOT, THAAD and GBI. For this, the S-500 system will implement a series of radar allowing low altitude, high altitude and long range coverage as well as a radar having an anti ballistic missile function.
This radar suite will be associated with a 360 ° firing line (4 plate radars?). Implementing a range of varied missiles adapted to all the targets that the system will be likely to destroy. On reading the ambitions displayed for this system (which will have to be confirmed during tests), it appears that the S-400 is only an intermediate system making it possible to make the junction between the aging S-300 and the future S -500.
It is also interesting to remember that the first name of what would become the S-400 was then S-300 PMU-3, recalling the relationship of this system with previous models. We then understand better why the Russians do not hesitate to sell it abroad, even outside countries that are part of their historical sphere of influence. It then seems that the Russians plan to base their air defense on the future-500 and that the S-400 will only be an interim system.
We also guess that the name S-400 instead of S-300 PMU-3 is undoubtedly a marketing approach intended to strengthen the appeal of the system on the international market. This does not detract from the qualities or effectiveness of the system, since it made it possible to implement a first generation of certain subsystems (radars and missiles) which will be reused in a modernized version on the S-500.
The entry into service of the S-500 will probably lead to the gradual withdrawal of the different generations of S-300, the S-300VM anti-missile systems and the A-135 GALOSH system. The anti-aircraft defense being supplemented by the S-400 already acquired, the S-350 for medium range, the TOR-M2 (SA-15), PANTSIR-S2 (SA-22) and the future SOSSN system for short range, to which are added the profusion of anti-aircraft guns and very short-range portable missiles (SATCP). A wide range of equipment designed to face a wide range of threats.