The Russian Navy is buying 24 MiG-29Ks (for about $42 million each) to replace the Su-33s currently operating from the aircraft carrier Kuznetsov. It was last year that the carrier version of the Russian MiG-29, the MiG-29K, made its first flight, about fifteen years later than originally planned. India is buying 30-40 of these for use on at least two aircraft carriers. The Indians are already receiving the first sixteen. The reason for dropping the Su-33 is the order from India. It's cheaper to build 64 (or more, for planned Russian carriers) MiG-29Ks, than just 16 more Su-33s to replace the ones already on the Kuznetsov (and wearing out). The MiG-29Ks are lighter and cheaper than the Su-33s.
In the early 1990s, work began on creating a variant of the MiG-29 for carrier use. These were to be used on the Kuznetsov class carriers, originally conceived of as 90,000 ton, nuclear powered ships, similar to American carriers (complete with steam catapults). Instead, because of the cost, and the complexity of modern (American style) carriers, the Russians were forced to scale back their goals, and ended up with the 65,000 ton (full load) ships that lacked steam catapults, and used a ski jump type flight deck instead. Nuclear power was dropped, but the Kuznetsov class was still a formidable design. The thousand foot long carrier ended up carryings a dozen navalized Su-27s (called Su-33s), 14 Ka-27PL anti-submarine helicopters, two electronic warfare helicopters and two search and rescue helicopters. The ship was designed to carry up to 36 Su-33s and sixteen helicopters.
The 33 ton Su-33 is larger than the 21 ton MiG-29K, and both types of aircraft were to operate from the three 65,000 ton Kuznetsovs. But when the Cold War ended, only the Kuznetsov was near completion. The second ship in the class, the Varyag, was sold to China. The smaller Gorshkov is being rebuilt and sold to India (who believed the smaller MiG-29K was more suitable for this carrier.).
The MiG-29K modifications included arrestor gear and stronger landing gear for carrier landings, folding wings and rust proofing to reduce corrosion from all that salt water. Anti-radar paint is also used, to reduce the radar signature. Fuel capacity was increased 50 percent and more modern electronics installed. A more powerful engine is used, which enabled the aircraft to carry over five tons of weapons (air-to-air and anti-ship missiles, smart bombs).