This chart shows all of the versions of Russia's fifth-generation fighter jet
The US and Russia have been competing arms exporters since the dawn of the Cold War.
Although the Soviet Union collapsed in 1991, the deep-seated rivalry between the US and Russia never fully died out and is now stronger than it's been in decades thanks the Russian annexation of Crimea, the war in Ukraine, and competing interests in Syria. Likewise, the two countries are equally competitive in the realm of military hardware.
The US and Russia are both producing their own fifth-generation fighters. While the US is developing the F-35 in conjunction with select worldwide partners, Russia is developing its own fifth-generation fighter, the Su-50.
And like the F-35, the Su-50 will have multiple variants. The following chart from Russian arms manufacturer Sukhoi shows the intended plan for all versions of Russia's most advanced fighter jet.
The base model of the Su-50 is also known under its prototype name of the T-50 PAKFA. There have been five T-50s built so far. The plane's final version (the Su-50) is supposed to be fully operational by 2016.
Once complete, the Su-50 will serve as a base model for future fifth-generation aircraft. Some versions of the plane are intended for export, with the bulk of them being developed for India.
The Indian version of the plane, called the Su-50E, will be similar to the Su-50 but modified according to certain demands from the Indian Air Force. Russia and India are also co-developing the Su55-FGFA, a twin-seater version of the Su-50 that will be specially designed for the Indian Air Force.
Aside from India, Russia also plans to complete variants of the Su-50 for South Korea and Iran. The South Korean version, the Su-50EK, should be ready for export by 2018 while the Iranian Su-50ES version will be ready by 2022.