Thread by @John_A_Ridge

Missiles of Ukraine I - Sapsan
OTRK (Operational-Tactical Missile System) "Sapsan" [peregrine in 🇺🇦] is a prospective single-stage, solid-fuel, short-range ballistic missile system. It has been under development in various forms since the mid-90s under a variety of names. 1/46

For clarity, Sapsan currently refers to the domestic variant, while "Hrim-2" ["thunder" in 🇺🇦] refers to the reduced range (MCTR compliant) export version. It’s also been referred to as "Grom" ["thunder" in 🇷🇺] or "Grim," a corruption of Hrim. 2/46

There is a profound asymmetry between 🇷🇺’s ability to strike targets in 🇺🇦 and 🇺🇦’s ability to strike targets in occupied 🇺🇦 territory and 🇷🇺. This asymmetry is a grave threat to both 🇺🇦’s war effort and its people that must be urgently addressed. 3/46

There are substantial critical 🇷🇺 military assets deep in occupied-🇺🇦 territory, particularly Crimea, that are largely inaccessible to 🇺🇦 strikes. It is imperative that 🇺🇦 gain the capability to reliably strike these targets. 4/46

Equally, there are numerous enormously valuable strategic assets within 🇷🇺 (and 🇧🇾) itself. These include airbases housing strategic bombers, AEW&C, and C2 aircraft; military factories; port facilities; C2 nodes; rail and road bridges along logistical arteries; etc. 5/46

Each of these represents a grave threat and they must be eliminated by any means available. If 🇺🇦’s allies are unable or unwilling to provide the relevant munitions, then we must aid the development, production… 6/46

…, and deployment of capable domestic 🇺🇦 systems and munitions. Sapsan is one of these munitions and it is arguably the most capable and significant 🇺🇦 system that 🇺🇦’s allies can support the fielding of. 7/46

Design:
Sapsan is broadly analogous in its intended role to the 🇷🇺 Iskander-M/K as well as the 🇺🇸 ATACMS and PrSM. It was originally conceived as a multi-role launch platform for both SRBMs and ground-launched cruise missiles. 8/46

The published maximum range of Sapsan is 500 km (280-300 km for Hrim-2) with a 480 kg unitary or cluster munition warhead, likely derived from Tochka-U. The est. damage radius of the unitary warhead is ~55 m or a 10,000 - 30,000 sq. m area for the dispersal of submunitions. 9/46

According to the designers, the 500 km max range is a political restriction as 🇺🇦 had been abiding by the INF though not technically a party to the treaty. It should be possible to increase the maximum range to 1,500 km, making it a medium-range ballistic missile. 10/46

Such a dramatic increase in range is achievable by using a lighter warhead combined with reductions in structural mass and improvements to motor performance. It is also possible that a small second-stage or kick-stage motor could be added as well (this is my speculation). 11/46

Guidance is via GNSS/INS (global navigation satellite system/inertial navigation system), likely using both GPS/GLONASS. This is supplemented by a choice of four active seeker heads: electro-optical contrast (EO), infrared (IR), active radar (3 mm), or combined EO/radar. 12/46

These seeker heads work by observing the terrain beneath the missile in their respective wavelengths and comparing it to a pre-loaded terrain map to estimate position. Combined with GNSS, this is used to correct the inherent INS drift/error that accumulates in flight. 13/46

Sapsan can follow ballistic and quasi-ballistic trajectories as well as maneuver during flight to extend its range and evade ballistic missile defense (BMD) systems. Maneuvering is performed using both aerodynamic control surfaces and a series of attitude control thrusters. 14/46

Much like ATACMS and PrSM, Sapsan’s terminal flight profile is thought to include a near-vertical dive toward its target to maximize both terminal velocity and precision. Terminal velocity is likely in excess of Mach 4 and probably in the range of Mach 5-6. 15/46

It is also notable that relatively modern and sophisticated manufacturing techniques were used in its construction. The use of additive manufacturing (3D printing) and powder metallurgy for metal components and a composite (e.g. carbon fiber) motor casing were referenced. 16/46

Capabilities:
If operational, Sapsan would provide a potent standoff capability to 🇺🇦. A 280+ km range would enable deep strikes anywhere within occupied 🇺🇦 (including Crimea), not to mention deep within 🇷🇺 itself, particularly if the range is enhanced to >500 km. 17/46

The option of a cluster munition warhead offers enhanced capabilities against dispersed targets that the latest versions of ATACMS, having only a unitary warhead, lack. This is especially valuable when targeting installations such as airbases where targets may be dispersed. 18/46

Sapsan being 🇺🇦 designed and manufactured mitigates potential restrictions that might be attached to the use of foreign-provided systems like ATACMS. This would give 🇺🇦 a much freer hand to strike critical targets in 🇷🇺 such as airbases, military factories, or C2 nodes. 19/46

🇷🇺 IAMDS (integrated air & missile def. system) would be severely challenged by Sapsan. As a 🇷🇺 miblogger notes, it’s unlikely that S-300/400s near the target could intercept Sapsan in terminal phase as it would descend in the funnel-esque radar dead zone above S-300/400. 20/46

In this dead zone, command-guided, semi-active radar homing (SARH), and track-via-missile (TVM) interceptors are ineffective if they rely on organic ground-based radars for off-board target illumination. This includes the standard 5V55 and 48N6 interceptors for S-300/400. 21/46

Providing illumination using airborne or remote radar inorganic to the launching system could potentially solve this issue, but it’s unclear if 🇷🇺 IAMDS has achieved the necessary level of integration or operator skill to perform this kind of interception. 22/46

A recent report from @RUSI_org on VKS (🇷🇺 Air Force) operations has revealed notable deficiencies in the integration of 🇷🇺 A-50U/M AEW&Cs aircraft and Il-20M relay/C2 aircraft that has degraded their ability to pass useful fire control data to relevant S-300/400 systems. 23/46

🇷🇺’s dilemma is further worsened by Sapsan’s estimated 25-70+ km apogee. A mid-course intercept at the upper end of those altitudes is likely outside S-300/400’s engagement envelope for most available interceptors. 24/46

Sapsan’s extreme maneuverability due to its attitude control thrusters, estimated on the order of 20-25g overloads (equiv. to a rapid 90-degree turn). This likely significantly exceeds the maneuvering capabilities of 5V55 and 48N6 series interceptors. 25/46

The proposed solution is the use of 9M96 series of ARH (active radar homing) interceptors from an S-350 system (though S-300/400 also support 9M96). It is cited as 🇷🇺’s only interceptor maneuverable enough to intercept a ballistic target maneuvering with 20-25g overloads. 26/46

The 9M96’s ARH combined with its INS and mid-course update capability would potentially enable interceptions in the radar dead-zone. The availability of 9M96 is unclear. It has yet to be publicly observed deployed in/near theater outside of a lone S-350 system in Taganrog. 27/46

Equally, I will speculate that 🇷🇺 IAMDS would likely be unable to reliably intercept Sapsan given S-300/300V/400’s observed inability to intercept GMLRS and the failure to intercept the ballistic missiles (likely ATACMS or Sapsan) that were used to strike the Saky air base. 28/46

It is also notable that during the Nargorno-Karabakh War in 2020, 🇦🇲 S-300s totally failed to engage, let alone intercept, any of the 🇮🇱-made LORA tactical BMs deployed by 🇦🇿. Like Sapsan, LORA is capable of maneuvering and following quasi-ballistic trajectories. 29/46

The major unknown among Sapsan’s capabilities is its precision beyond vague statements of “meters.” Vilkha-M, a 🇺🇦 precision-guided MRL (multiple rocket launcher) round with GNSS/INS, has a quoted CEP (circular error probable) of <30 m at 120 km or <10 m at 70 km. 30/46

While quite poor compared to analogous 🇺🇸 systems, Sapsan’s CEP is likely superior to Vilkha-M as Sapsan has active seekers that Vilkha-M lacks, in addition to GNSS/INS. It is also possible that Sapsan may have a higher quality GNSS/INS package given its intended role. 31/46

Readiness-
All these technical details come back to the fundamental question, does Sapsan exist? Is it operational? The short answer: It is uncertain but possible. When the program was restarted in 2021 after being paused since 2019, development was reportedly 80% complete. 32/46

Prior to 2021, the solid rocket motor had successfully undergone hot fire testing and at least 12 motors had been manufactured. Development and testing of the active seeker heads had also reportedly been completed as had warhead testing. 33/46

At least two TELs had been manufactured, one for Sapsan and one for Hrim-2. It’s important to note that Sapsan and Hrim-2 differ in diameter, ~900 mm and ~600 mm respectively. It is unclear if a Hrim-2 TEL can support a 900 mm Sapsan missile or just a 600 mm Hrim-2. 34/46

Now we come to export customers. According to 🇺🇦 sources there were two prospective export customers for Sapsan. The first is 🇸🇦. It has been widely reported that 🇸🇦 heavily financed the development of Hrim-2/Sapsan, contributing $70-200 mln. 35/46

It is known that in 2019 a prototype Hrim-2 system, including “motors, warheads, and spare parts” was exported to 🇸🇦 for testing. It is unclear if the system was complete or included fully functional missiles or the prototype Hrim-2 TEL. 36/46

There were unconfirmed reports published a few months ago that 🇸🇦 had returned the Hrim-2 system to 🇺🇦 as part of an agreement brokered by 🇺🇸. However, details regarding any such agreement are scarce and it remains completely unknown if such a transfer occurred. 37/46

Following the resumption of the program in 2021, a number of changes were announced including a change in TEL to one based on a 🇨🇿 Tatra chassis which was to become a multi-functional chassis supporting a number of other weapon systems. 38/46

It is unclear how much, if any, funding was actually allocated for the program in 2021. According to @TarasChmut, significant funding wasn’t actually allocated until 2022, with a specific focus on completing the 280 km Hrim-2 variant. 39/46

It was also reported that following the program’s resumption, the 🇺🇸 apparently expressed interest in procuring the system (the other prospective customer). I’ll speculate that the 🇺🇸 wanted to either evaluate it or procure some of the underlying technology. 40/46

The big news was a report from @BBC_ua published in Sep. concerning an espionage case involving KB “Pivdenne,” which is involved in development. It indicated that development of Sapsan had been completed by late June 2022 and serial production was being initiated. 41/46

It is unclear if this referred to the development of Sapsan specifically or Hrim-2 (or both). Likewise, it is equally unclear if serial production referred to Sapsan or Hrim-2. From an engineering standpoint, a less ambitious 280 km variant would be easier to complete. 42/46

However, a 🇷🇺 cruise missile strike on July 2 against a facility in Pavlohrad, likely the solid propellant production plant, reportedly disrupted these efforts. This was followed by a 🇷🇺 strike against the primary Pivdenmash manufacturing plant in Dnipro on July 16. 43/46

Pivdenmash is one of 🇺🇦’s primary rocket and missile manufacturers and was heavily involved in Sapsan’s creation. It’s unclear what the long-term impacts of such strikes on development would be. Per the @KyivPost, it’s widely believed that most of Pivdenmash’s… 44/46

…missile production lines are located in underground facilities hardened against nuclear strikes. A legacy of the Soviet Union’s civil defense paranoia. This is somewhat speculative since official details were state secrets of the USSR and continued as state secrets of 🇺🇦. 45/46

There has not been any additional reporting on the program’s status since September. I will consider appending a sequel to this thread in the event there is additional reporting on the status of the program in the future. 46/46

A massive thanks and shoutout to @DEFENSEEXPRESS for their fantastic coverage of Sapsan and many other 🇺🇦 weapon systems. This thread would not have been possible without their reporting. Stay tuned for Part II of this series covering 🇺🇦’s Neptun AShM in the coming weeks.