The Russian Air Force put into operation the first Su-57 fighter in December 2020, and it is expected that by 2027 there will be 76 aircraft
The Su-57 is currently considered a fifth-generation fighter, but the airframe has been used to test a number of weapons with sixth-generation technology
including hypersonic missiles, artificial intelligence (AI), and unmanned aerial vehicles
The Su-57 will also be equipped with Saturn-30 engines from 2022
which will significantly improve its flight performance and range
which is already among the highest in the world and is well suited to the Russian Air Force's long-range strike operations
Despite its impressive performance, the potential of any fighter in air combat depends heavily on the air-to-air missiles it carries
Most Russian fighters (including the most advanced Su-35 today), use the R-27 long-range air-to-air missile
this is a modernized variant, based on a missile developed by the Soviet Union during the Cold War
The R-27 is the world's most advanced, semi-active radar homing missile
but its capabilities are far behind that of modern missiles using active radar guidance such as the US AIM-120C/D
Europe's Meteo, or China's PL-15
Russia has developed a new specialized long-range air-to-air missile, the K-77M
developed for the Su-57, to give it an edge over its main competitors
With a range of over 190 km, this is not the longest range air-to-air missile Russia has developed
But in general, K-77M is the most complex air-to-air missile that Russia has ever built
The K-77 has a range longer than the top American missile the AIM-120D which reaches 180km
but short of the Chinese PL-15 which reaches an estimated 250-300km
What makes the K-77's introduction particularly significant, aside from its more compact size and longer range
is the fact that its active phased array antenna (APAA) guidance technologies
make it extremely accurate even against small and agile targets at extreme ranges
A sophisticated radar system in the missile's nose can overcome the radar’s “field of view” problem
allowing the missile to retain a lock 360 degrees around itself, and thereby preventing fighters from evading its “field of view” by ducking past it
This will provide the missile with a ‘no escape range’ several times as long as that on the R-77, and much longer than those of the AIM-120D or PL-15
Russian state media outlet RT explained the active phased array antenna technology used by the K-77 as follows
“An active phased array antenna consists of a large number of cone-shaped cells installed under a transparent-to-radio-waves cap on the nose of the missile"
Each cell receives only a part of the signal, but once digitally processed, the information from all cells is summarised into a ‘full picture,’
enabling the K-77M missile to immediately respond to sharp turns of the target, making interception practically inevitable
Integration of the K-77 is but the latest example of the Su-57 fighter
pioneering groundbreaking new technologies which other countries may only later begin to develop themselves
In addition to the Su-57, the K-77M missile can be used to arm other Russian fighters such as the Su-35
Su-30SM2 and Su-27SM3, all of which have relatively modern radars, suitable for guiding the K-77M
The K-77M missile will be key to partially restoring Russia's missile advantage
and preparing the Russian Air Force to face next-generation threats, such as the future US missile AIM-260