Images released last week by Ukrainian military news sites show what is suspected to be debris from a long-range R-77M air-to-air missile. This is a significantly upgraded version of the medium-range R-77 air-to-air missile developed by the Soviet Union and Russia.

"The missile's tail fins appear flattened and short, rather than the grid-like fins perpendicular to the body seen on older R-77 models. This suggests the debris is likely from the newer R-77M missile," observed Thomas Newdick, editor of the US military news site War Zone.

Missile debris believed to be from an R-77M, in a photo released 25/7. Photo: War Zone, Polkovnyk GSh

A photo of an Su-35S fighter jet, released by Russian media on 25/7, also shows the aircraft carrying two R-77M missiles on underwing pylons near the engine intakes, along with an older R-77-1 missile on the right wing and an R-74M on the left wing, as well as electronic warfare pods on both wingtips.

Neither the Russian Ministry of Defense nor the Ukrainian military has commented on the information.

The original R-77 medium-range air-to-air missile uses an active radar seeker and has a range of 80 km. It was developed by the Soviet Union in the 1980s as a counterpart to the US-made AIM-120 AMRAAM. The US Air Force has used the AIM-120 since 1991, while the Russian Air Force began deploying the R-77 in 1994.

In 2015, the Russian military adopted the upgraded R-77-1 variant, which extended the range to 110 km with minor aerodynamic improvements and a more sensitive and jam-resistant radar seeker, but retained the grid-like fin design.

The R-77M version, also known as Izdeliye 180, was developed for the Su-57 stealth fighter and can reportedly achieve a range of about 195 km.

"The new fin design allows the R-77M to fit inside the Su-57's internal weapons bay, as well as reducing drag and the missile's radar cross-section. The new engine significantly improves thrust and maneuverability, while the active electronically scanned array (AESA) radar enhances target acquisition," Newdick said.

Missile debris believed to be from an R-77M, in a photo released 25/7. Photo: War Zone

Douglas Barrie, a senior fellow for military aerospace at the International Institute for Strategic Studies (IISS) based in the UK, considers the R-77M an important air-to-air missile for the Russian Air Force. "The R-77M offers significant improvements in range, seeker performance, and resistance to jamming compared to the R-77-1. It wouldn't be surprising if Russia continues to use this weapon in combat in the conflict with Ukraine," he stated.

The longest-range air-to-air missile currently in Ukraine's possession is the AIM-120C, which can hit targets at ranges of 90-160 km, depending on the version and firing conditions. Meanwhile, Russian MiG-31, Su-35S, and Su-30SM fighters can be equipped with the R-37M, capable of hitting targets at a distance of 300 km.

"The appearance of the R-77M further complicates the situation for Ukrainian pilots, especially since the Russian air force already possesses a variety of air-to-air missiles with superior range compared to their Ukrainian counterparts," Newdick warned.

Nguyen Tien (According to War Zone, AFP, AP)