The RIM-7 Sea Sparrow will be paired with Soviet-era Buk launchers and radar systems in a bizarre but potentially much needed mash-up.
By THOMAS NEWDICK and TYLER ROGOWAY
Jan 6, 2023
The War Zone
Ukraine is to receive an undisclosed number of radar-guided RIM-7 Sea Sparrow surface-to-air missiles, or SAMs, which will be integrated onto the Ukrainian Armed Forces’ existing Soviet-era Buk air defense systems. The missiles are included as part of the latest U.S. aid package for Kyiv officially announced today, which significantly also includes M2 Bradley infantry fighting vehicles.
The provision of Sea Sparrow missiles was first disclosed by Politico. Most interestingly, the same story, citing two unnamed people familiar with the matter, noted that Ukraine has already succeeded in integrating the U.S.-made missiles into its Buk system. No further details of this “bit of battlefield innovation” were provided. The integration with the Buk system was subsequently confirmed to The War Zone.
The Buk series are tracked self-propelled SAM systems, the first versions of which date from the later part of the Cold War. Buks of various types have seen extensive use in the conflict in Ukraine, on both sides. The system is probably best known for the tragic shoot-down of MH17 over eastern Ukraine in 2014.
In its original form, Raytheon’s RIM-7 Sea Sparrow was a direct development of the AIM-7E Sparrow air-to-air missile. In its naval application, the RIM-7 became hugely popular and has served widely with the U.S. Navy and many allied nations since it first entered service in 1967.
Primarily born as a fast-reaction point-defense system that has grown into an intermediate-range weapon for warships, the RIM-7 Sea Sparrow is able to intercept aircraft or cruise missiles. It can also engage surface targets under certain circumstances. In particular, it was tailored to defeat pop-up anti-ship missiles, which can appear with very little notice, and which move fast and low over the water. In maritime use, the range of the basic Sea Sparrow is limited to around 12 miles, although most engagements would be at a shorter range, depending on the intercept parameters, conditions, and the specific variant of the RIM-7 missile and fire control system. For instance, early versions used manually directed radar illuminators. Then the system became more automated and integrated with the ship’s fire control architecture. Today, the latest RIM-162 Evolved Sea Sparrow Missile (ESSM) Block II variant features an active seeker and datalink and is capable of working without illuminators at all.
The RIM-7 Sea Sparrow missile, and the RIM-162 Block I ESSM, uses a concept of operations based on a semi-active radar homing guidance principle, or SARH. In this way, the launch
platform (normally a warship) is required to have a radar to detect and track the target, and then it needs to ‘illuminate’ or ‘paint’ it with a continuous-wave radar beam for engagement. Oftentimes, an entirely separate radar is used to first spot and track the target. The missile is fired toward the target, and once illuminated, the sensitive SARH seeker in its nose that is tuned to the radar’s particular signal can be guided toward it for its endgame attack. The missile follows the radiation reflected from the target by the illuminator either until it impacts or passes close enough for the proximity fuse to be triggered.
The RIM-7 integration with the Ukrainian Buk system will share many of the same disadvantages of the original naval point-defense system, including limited range — primarily a product of the AIM-7E having been designed for launch from a fast-flying fighter already at altitude. Also, the missile’s centrally mounted maneuvering fins are not best suited to making rapid adjustments to account for fast and agile targets.
On the other hand, the RIM-7 should still provide a very useful, localized capability against many of the kinds of threats that Ukraine now faces. These include subsonic cruise missiles (as seen in the video embedded below), as well as a variety of drones, battlefield helicopters, and low-flying manned aircraft.
Another major point in its favor for Ukraine is the fact that the RIM-7 Sea Sparrow is highly adaptable for different types of launchers. In the maritime context, the familiar Mk 29 automated launcher is still in use today, while other versions have included manually aimed box launchers, vertical launch variants, and new modular launchers that adopt that system, as well as the unique installation found in Canada’s Iroquois class destroyers..
Until now, however, the RIM-7 has seen little service in ground-based applications. Taiwan, Egypt, and Greece are among those who use or have used the Sea Sparrow missile loaded in box launchers as part of their versions of the Skyguard short-range air defense systems (SHORADS), which can accommodate various missiles and guns to protect high-value assets.
While the Skyguard/Sea Sparrow was designed for defending fixed installations, putting the same missile onto the highly mobile Buk transporter erector launcher and radar (TELAR) vehicle also makes it much more flexible. In this form, it should be able to defend high-value static targets as well as move alongside armor and infantry to offer defensive cover closer to the front lines of the battlefield. Its ability to rapidly relocate also makes it much more survivable.
The much more capable RIM-162 Evolved Sea Sparrow Missile, or ESSM, is also widely used by navies around the world. There’s no indication, at this stage, that Ukraine is expected to receive this missile, too. As it sits now, RIM-7 will be what they are getting.
When it comes to Buk, even in its unmodified form, it has already proven itself to be one of Ukraine’s most useful ground-based air defense systems. Each of the 9K37M1 Buk-M1 (SA-11 Gadfly) TELARs that Ukraine uses normally carries four ready-to-fire missiles, as well as its own fire control radar. The maximum engagement range of the original 9M38 series missile is 22 miles, so this would be reduced with the RIM-7. However, it’s possible that the adaptation will
allow a combination of missiles to be loaded, with the Sea Sparrows being loaded together with 9M38 series missiles to make the most of their respective capabilities.
Like the RIM-7 Sea Sparrow, the 9M38 series missile fired by the Buk-M1 employs semi-active radar homing, although the Buk’s normal missiles not only have significantly greater range but are also much bigger and heavier, at over 1,500 pounds per round compared to around 500 pounds for the RIM-7. The 9M38 series missiles are also capable of engaging targets flying at up to 72,000 feet, while the RIM-7 tops out at around 50,000 feet, with its focus very much on low-flying targets.
Ukraine entered the war with a reported 72 examples of the Buk-M1 system available. Since it’s not fielded by any NATO nations, getting hold of original missile reloads for the Buk system is a big problem and it could well be the case that, with missile stocks running low, the Sea Sparrow has been identified as the best stopgap solution. It’s also the case that Ukrainian Buk systems have come under attack from Russian forces, too. We don’t know how many Sea Sparrows are being supplied, but there should be plentiful stocks at least of RIM-7s across NATO, especially as the RIM-162 ESSM continues to replace it. This is similar to the situation with the National Advanced Surface-to-Air Missile System (NASAMS)/AIM-120 pairing, which also benefits from a very deep NATO magazine to draw from.
At this stage, it’s also unclear how, exactly, the Sea Sparrow has been integrated with the original Soviet-era radar and fire control system. However, at least one previous effort has been made to convert the Buk’s predecessor, the 2K12 Kub (SA-6 Gainful), to fire the original Sparrow and/or Sea Sparrow missiles. Around 2008, the Polish defense contractor Wojskowe Zakłady Uzbrojenia, or WZU, displayed a Kub system that had been adapted to fire RIM-7 Sea Sparrow missiles. In this case, the Kub launch vehicle, which has three ready-to-launch missiles, was fitted with two Sparrows and one of the Kub’s original ramjet-powered missiles. Subsequently, WZU also pitched a conversion of the Kub with canister-launched RIM-162 ESSM missiles, although neither variant is understood to have found any customers.
Similarly, the Retia defense company from the Czech Republic developed a Kub upgrade that added three Aspide 2000 missiles in launch containers, which was displayed in 2011. The Aspide 2000 is an Italian-made SAM derived from the same AIM-7E that was used as the basis for the original RIM-7 Sea Sparrow. One Aspide 2000 battery has also been supplied to Ukraine by Spain for the defense of static objectives, and it’s possible that there could be some crossover between this and the adapted Buk. At the least, it would seem to offer the opportunity for missile stocks to be shared between the two different systems.
Whatever challenges inevitably exist in bringing a NATO-standard missile into a Soviet-designed air defense system, they are clearly not insurmountable.
It’s unclear if either the WZU or Retia conversion played into the Ukrainian “battlefield innovation” to any extent, if Raytheon assisted with the integration, or whether the conversion was done entirely independently by Ukrainian technicians, which seems unlikely. However, there is at least one previous example where Ukraine has taken a Western missile and then
successfully integrated it with a Soviet-era platform: in this case, the AGM-88 High-speed Anti-Radiation Missile (HARM) and the MiG-29 Fulcrum and Su-27 Flanker fighter jets. Perhaps even more relevant are the initiatives to field a ground-launched version of the Brimstone missile, as well as the Ukraine-specific ground-based Harpoon anti-ship missile system that was developed with assistance from Boeing.
Overall, Sea Sparrow missiles headed to Ukraine are in keeping with previously publicly announced initiatives to expand Kyiv’s overall air and missile defense networks, and it seems that these weapons will now be added to a growing array of Western air defense systems already flowing into the country.
Clearly, Ukraine still has a pressing demand for ground-based air defense systems and, with Soviet-era arms becoming increasingly harder to replenish, it is willing and able to develop solutions that bring together Western missiles to make the most of its still-capable Cold War-era hardware. Sea Sparrow plus the Buk TELAR could not only be a powerful combination for defending static high-value targets, like power infrastructure and major population centers, and even troop concentrations on the move, but also for prowling near the front lines, ‘popping up’ and radiating to ambush Russian aircraft before going silent and relocating.
It will be fascinating to see just how the Sea Sparrow has been integrated with the Buk and we will continue to update this story once more details become available.