All Ukrainian Osa surface-to-air missile systems currently in service with the Ground Forces of the Armed Forces of Ukraine have now been upgraded and can utilize an additional missile - the R-73.
This information was shared by the "Come Back Alive" foundation, which, as part of the Hornet project, "has for the first time in charity history upgraded a surface-to-air missile system."
The modernization of these SAMs took a considerable amount of time, but the Ukrainian Armed Forces officially showcased the Osa SAM with new missiles only in June 2024. This is indeed a significant upgrade, as it addresses the issue of the shortage of standard 9M33 surface-to-air missiles.
With the efforts of the foundation, which managed to raise over 14 million hryvnias (approximately 340 thousand dollars), a certain number of systems were upgraded. Even if the cost for upgrading one SAM is around that amount, integrating a new missile into the system represents a highly effective and pragmatic expenditure.
Overall, this suggests that the total cost for the modernization of Ukrainian Osa systems could be around 22 million dollars, based on the Military Balance estimate that there were 65 such systems in service with the Armed Forces as of 2023. Even when factoring in the costs for developing the upgrade itself, in comparison to current weapon prices, this is indeed minimal.
Ultimately, an important aspect is the enhancement of the Osa's capabilities due to the R-73. It is worth noting that this is an "air-to-air" missile which, when launched from an aircraft, has a range of 20-40 km depending on the version. In contrast, the ground launch range will be significantly shorter; for example, the Yugoslav Pracka RL-4 SAM, which also utilized the R-73, had a declared range of up to 12 km.
This range is 2-3 kilometers further than the capabilities of the standard 9M33 missile, which has a more powerful warhead - 15 kg compared to 8 kg. However, in real-world applications of the Osa against drones and cruise missiles under current conditions, this difference is unlikely to be significant. The more critical issue is the channeling capability, specifically how many missiles the system can launch simultaneously.
The standard 9M33 missile relies on radio command guidance, and the Osa can only "track" two missiles at the same time. In contrast, the R-73 features an infrared homing head, allowing it to be directed towards another target immediately after launch.