TMB-597 Astarte III
| TMB-597 Astarte III | |
|---|---|
 Diagram view of the TMB-597 Astarte III SLBM. | |
| Type | Submarine-launched ballistic missile |
| Place of origin |  Carthage |
| Service history | |
| In service | 1991-present |
| Used by | Carthage Gensokyo Republic |
| Production history | |
| Designer | SHAFT ADS |
| Designed | 1983-1990 |
| Manufacturer | SHAFT ADS |
| Unit cost | $39.9 million (FY2012) |
| Produced | 1991-present |
| No. built | 4,000+ |
| Specifications (TMB-597AM3) | |
| Weight | 64,000 kg (141,000 lb) |
| Length | 13.8 m (45 ft) |
| Diameter | 2.3 m (91 in) |
| Warhead | 6 × Type-N45G MaRV w/R-102A thermonuclear warhead |
| Blast yield | 6 × 500 kilotons |
| Engine | Solid fuel rocket (1st & 2nd stages) Liquid fuel rocket (3rd stage) |
| Propellant | NEPE-75 (1st & 2nd stages) Aerozine/N2O4 (3rd stage) |
Operational range | Greater than 13,000 km (8,100 mi) |
| Flight ceiling | 1,500 km (930 mi)+ |
| Speed | 8,600 m/s (31,000 km/h) |
Guidance system | Astro-inertial w/satellite navigation |
Steering system | Thrust vector control |
Launch platform | Type-053N submarine Type-062N submarine |
The TMB-597 Astarte III (formerly SM-10 Astarte III) is a submarine-launched ballistic missile developed for the Punic Navy by SHAFT ADS. First deployed in 1991, it is the successor to the SM-09 Astarte II and the latest generation of the Astarte series of SLBMs. With the last Astarte II entering retirement in 2003, the Astarte III is the only SLBM in current service with the Punic Navy and forms the submarine-based leg of the Carthaginian nuclear triad. Upon entry into service it was the first SLBM in Carthaginian service to match the accuracy of land-based ICBMs operated by the Air Forces.
The Astarte III is currently carried by Carthaginian Type-053N and Type-062N ballistic missile submarines, with 24 missiles carried per boat. Since entering service in 1991 the missile has undergone a continuous program of modernization and improvement to remain a capable deterrent. The current missile fleet is expected to be superseded by the further improved Astarte IV beginning in 2019.
History
The Astarte III is the newest missile in the Astarte family of submarine-launched ballistic missiles, originating with the Astarte I which entered service in 1968 as the first solid-fueled SLBM in Punic Navy service. The Astarte II entered service in 1975 as a larger, longer-ranged and more capable successor to the Astarte I and was designed alongside the Type-053N ballistic missile submarine to extend the reach of the Strategic Submarine Force. The Type-053N/Astarte II weapon system was designed to increase the lethality and survivability of the Carthaginian strategic nuclear deterrent, and among other design features included an increase in missile diameter to 2.3 meters (91 in) from the existing 1.8 meters (71 in) to improve range and payload.
The Astarte II served throughout the Northern War despite never being fired in anger. No Type-053Ns were lost during the war and some historians have alleged the Astarte II system played a key role in deterring nuclear escalation. In spite of victory over the European Federation and Venetian Empire, the changing geopolitical landscape created new threats on the horizon, with the Confederate States and Sassanid Empire both making progress on ballistic missile defense programs. In response to these potential threats to the viability of the Carthaginian nuclear deterrent, the Navy commissioned the Future At-Sea Deterrent study in 1980 to evaluate technologies and concepts to preserve the survivability and viability of the Navy's strategic arm.
In 1982, the study results concluded that the most viable and technologically feasible program would be the development of a newer, higher-performance missile coupled with a maneuverable reentry vehicle to significantly increase the difficulty of interception. This new missile would incorporate design and guidance features enabling depressed trajectory flight if required to sharply reduce warning and flight time, another key feature to reduce vulnerability to missile defense networks. While the report recommended consideration of a further increase missile size to offset the lower efficiency and higher drag of a depressed trajectory flight, budgetary realities in the 1980s prevented the development of a new submarine with enlarged launch tubes and design work on a new missile to re-equip the Type-053N was initiated in 1982, with a target completion date of 1991 to coincide with the beginning of the refueling cycle for the Type-053N series.
To meet program timetables, development work on the Astarte III missile and the Type-N45 MaRV was separated, and the Astarte III was designed for compatibility with the existing Type-N43 RV as well. While SHAFT ADS held the position as lead contractor for the development of the Astarte III, design and testing of the Type-N45 and R-102 warhead was the responsibility of the Strategic Weapons Directorate of the Department of Science, Energy, and Technology. Development work continued throughout the mid-1980s on both programs and the first Astarte III launch occurred in April 1987, using stand-in reentry vehicles for the still-in-development Type-N45. A total of fourteen test launches were carried out during the development program from both land-based test stands and missile submarines, using both the Type-N43 RV and provisional models of the Type-N45. By May 1989 however it had become clear that progress on the Type-N45 had fallen behind schedule and that the project would be unable to meet the initial 1991 deadline. As a result, the Astarte III entered service in 1991 using refurbished Type-N43 RVs from the existing strategic stockpile.
Export
In 1985, the Japanese government established the Strategic Forces Modernization program to evaluate replacements for the domestically-produced Mitsubishi SRS-A SLBM. Although an entirely domestic program, the SRS-A shared the same dimensions as the Astarte II, and the idea of a joint program was raised at the Cairo conference in 1986. By this time, however, the Astarte III was sufficiently far along in development that joint funding and procurement was a difficult political proposition and no agreement was made. In 1989, Mitsubishi Heavy Industries signed a separate agreement with SHAFT ADS to allow licensed production of the first and second stage solid boosters for use in the Japanese SRS-B. While both missiles share the same boosters and are dimensionally similar, the Astarte III and SRS-B utilize different fire control and guidance systems and are not interchangeable without significant overhaul.
AM1 modernization
Following a period of program reorganization, the Type-N45 MaRV was assigned a new expected service date of 1993, using the new R-102 warhead. Additional improvements were planned for the Astarte III guidance system including the addition of satellite navigation via the Carthage Global Navigation System, also expected to reach initial operating capacity in the mid-1990s. This new guidance system, the Type-N45 RV along with the necessary modifications for its integration as well as a package of inspection and refurbishment were combined into the AM1 modernization program which began in 1996. Most AM1 models were new-build missiles designed to replace the existing stock of Astarte IIs still in service while submarines equipped with the earlier-model Astarte III received a lower upgrade priority.
AM2 modernization
Development of the more advanced Type-X46G MaRV began in 1994, building on research and experience from the Type-N45 and experimental RVs such as the SPEAR program and Hi-Flyt. By 2000, the program had demonstrated sufficient progress that the Navy committed to adopting the Type-X46G in its next round of missile upgrades, although this would require a substantially redesigned equipment stage to accommodate the larger dimensions and heavier weight of the Type-X46G relative to the Type-N45. The new design used advances in the miniaturization of digital electronics and the replacement of the previous suspended sphere guidance system with a more compact ring laser gyroscope to significantly reduce stage weight, maximizing weight and volume available for the payload. Following six test flights in 2005 and 2006, the adoption of the new AM2 standard was formally approved and funded in 2007.
Unlike the AM1 modernization which was primarily composed of new-build missiles, the AM2 modernization relied more heavily on reconditioning existing AM1 Astarte IIIs as the Astarte II had already been fully retired. A limited quantity of new-build AM2s were constructed to supplement spares stockpiles and replace defective units.
Successor
Consideration of a successor design to the Astarte III began in 2009 shortly after the introduction of the AM2 modernization program. Despite ongoing modernization programs for electronics components and regular inspections and tests of the rocket motors, the ages of the earliest missiles in service were reaching a point whether either replacement or significant refurbishment would be required. A 2008 study concluded that the development of a new design would be preferred in order to meet standing depressed trajectory range goals and incorporate newly-developed insensitive propellants. Positive effects on workforce readiness and industrial base experience were also identified. After a sustained lobbying effort in 2009 the legislature approved funds for the development of the Astarte IV, maintaining the same dimensions as the Astarte III but using new materials, solid fuel, and a more reliable guidance system.
Operational features summary
The Astarte III was designed for improved accuracy and resiliency against missile defense systems in a first strike scenario. Designed to fit within the existing launch canisters of the Astarte II, the Astarte III has the same physical dimensions but uses more advanced technology to achieve its design goals. While externally similar to the Astarte II due to physical constraints, the Astarte III is an entirely new design.
Significant improvements in guidance systems developed during the 1980s allowed the initial Astarte III to achieve a circular error probable of 120 meters (390 ft) using conventional unguided reentry vehicles in a standard flight profile, and the Astarte III is the first missile in Carthaginian service for which the guidance system no longer contributes significantly to error. This guidance system was further upgraded through the AM1 and AM2 modernizations and the Astarte III now uses guided maneuverable reentry vehicles for even greater terminal accuracy, with the CEP of the current Type-X46G RV reportedly reaching 10 meters (33 ft).
Despite being limited to the same physical dimensions as the Astarte II, the use of improved propellant and lighter body materials resulted in improved range, a key element to meet the requirements of the depressed trajectory specification. The Astarte III is designed to be launched on one of two trajectories:
- Minimum-energy trajectory: This course carries the missile on a conventional ballistic trajectory, optimized for the most efficient use of energy and allowing the greatest possible range. Using this course, it is estimated that the TMB-597 can strike targets in excess of 13,000 kilometers (8,100 mi) using conventional RVs and 14,000 kilometers (8,700 mi) using the Type-X46G glide vehicle. This trajectory however renders the missile more vulnerable to detection and engagement due a comparatively long flight time and high apogee in excess of 1,600 kilometers (990 mi).
- Depressed trajectory: This course carries the missile on a much lower trajectory with an apogee below 200 kilometers (120 mi) and possibly below 100 kilometers (62 mi), depending on desired range. This significantly reduces flight time and probability of detection but also significantly reduces range due to the greater amount of time spent in the denser layers of the atmosphere. This mode is considered particularly valuable for use as a first strike weapon against strategic bomber airfields and land-based nuclear weapon sites.
Elements of missile design were focused on improving performance in a depressed trajectory role, including a booster design capable of handling the stress of atmospheric flight and thicker heat shielding on the reentry vehicles. The reentry angles of 5-10° used in depressed trajectory courses results in significantly increased thermal stress compared to the 30-40° angles of ballistic trajectories. To accommodate this, a new carbon-phenolic thermal protection system was used in the Type-N43 and N45 RVs, while the newer Type-X46G uses a further improved carbon-carbon TPS.
In addition to depressed trajectory capabilities, the Astarte III incorporates several other features to defeat missile defense systems, including maneuvering reentry vehicles (in the AM1 and AM2 specifications), a reduced signature design for the equipment stage, and a number of active decoys used in the terminal stage. These active decoys replace the previous passive decoys used in earlier missiles and are equipped with deceptive jammers to increase effectiveness against increasingly powerful and capable missile warning radars. The AM2 modernization replaced the initial ESX-103 jammer design with the more advanced AW/SAD-2004 jammer, with improved signal processing and digital memory for better performance against more modern missile defense systems capable of discriminating against simpler decoys.
Description
Guidance
The Astarte II relies primarily on astro-inertial guidance, although newer guidance systems include provisions for satellite navigation. The initial guidance system was the M4760 astro-inertial system, relying on a fluorocarbon-suspended sphere for inertial reference, a significant leap over previous gimballed systems which were prone to "gimbal lock" under certain conditions. At apogee, the guidance system relies on stellar position matching using an onboard camera to determine fixed points of reference, orienting itself as required. The M4760 guidance package relies on a single camera for this purpose, an improvement over the dual-camera system used in the M4650 guidance system used in the Astarte II. Using the M4760, the estimated CEP of the Astarte III is 120 meters (390 ft).
The M4760 guidance system was replaced as part of the mid-1990s TMB-597AM1 modernization program by the M4820 guidance system, which added satellite navigation capability in preparation for the completion of the Carthage Global Navigation System. With the introduction of the guided Type-N45 reentry vehicle, total system CEP was further reduced to an estimated 40 meters (130 ft).
A further modernization of the guidance system in the mid-2000s replaced the M4820 with the M5010, utilizing a more accurate and sensitive star tracking camera, improved satellite navigation receivers, and a new ring-laser gyroscope, replacing the previous suspended sphere design. The change was part of the AM2 modernization program and aimed to further reduce guidance system volume and weight in order to compensate for the larger Type-X46G reentry vehicle. In conjunction with the Type-X46G reentry vehicle's onboard guidance system, the CEP of the TMB-597AM2 is estimated to be approximately 10 meters (33 ft).
Reentry vehicle
The Type-N43 RV originally entered service in 1975 alongside the Astarte II missile, housing the R-101 warhead. 1.9 meters (6.2 ft) in length and with a maximum diameter of 60 centimeters (24 in), the Type-N43 uses a conventional sphere-cone body design. Unlike the later Type-N45 and Type-X46G, the Type-N43 is not guided and is purely ballistic after release from the equipment stage. Initial RVs on the Astarte II suffered from loss of accuracy caused by uneven ablation of the nosecone thermal protection system but this was solved in later models through the use of a new stable shape nose and carbon-phenolic heat shield.
The Type-N45 MaRV entered service in 1993 and introduced the new R-102 warhead. Using a biconic design rather than a standard sphere-cone shape, it is the first maneuverable reentry vehicle in Carthaginian service and uses an onboard inertial guidance system controlling a series of aerodynamic flaps to actively control its flight during reentry. In normal use the Type-N45 is programmed to follow one of several pre-set evasive courses to reduce the chances of interception. In 2001 the Type-N45 was upgraded with satellite navigation capability and its evasive course library altered to include more maneuvering in the lower atmosphere, providing sufficient time for a satellite link to be reestablished following the dissipation of the reentry plasma sheath. The Type-N45 exhibits limited cross range capability of approximately 200 kilometers (120 mi). The Type-N45 is 2 meters (6.6 ft) in length and 60 centimeters (24 in) at its base, with a mass of 470 kilograms (1,040 lb).
The AM2 modernization introduced the Type-X46G MaRV, a significant departure from past designs. The Type-X46G uses a combination of small wings and flaps to give it significantly increased cross range capability, expanding its range of targets and maneuvering envelope. The guidance package is similar to that of the Type-N45 but incorporates a more accurate INS and more reliable satellite navigation capability. On a minimum-energy ballistic trajectory, the Type-X46G has a maximum cross range maneuvering capability of 1,500 kilometers (930 mi), increasing total missile range beyond 14,000 kilometers (8,700 mi) in normal use and 5,000 kilometers (3,100 mi) on a depressed trajecotry. To accommodate the greater thermal stresses imparted by a longer period of atmospheric travel, the Type-X46G has a thicker carbon-carbon thermal protection system than the Type-N45.
Warhead
Upon entry into service, the TMB-597 was armed with the R-101 warhead mounted in the Type-N43 reentry vehicle, the same warhead and RV used in the later versions of the previous Astarte I. The R-101 warhead was a standard Teller-Ulam design with a yield of 450 kilotons and was the first Carthaginian warhead suspected to use an oblate primary for better volume efficiency in the physics package. Initial missiles were furnished with warheads and RVs from existing Astarte I stockpiles pending the introduction of the in-development Advanced Maneuverable Reentry Vehicle.
By 1993, the new R-102 warhead and Type-N45 reentry vehicle were introduced. The R-102 was specifically designed for the new Type-N45 maneuverable reentry vehicle and has an increased yield of 500 kilotons due to the use of additional enriched uranium in the fusion tamper. It is not known if the R-102 uses an oblate primary like the R-101, as the wider body of the Type-N45's biconic design reduces the need for such a complex design. The warhead is believed to have a length of 1.8 meters (71 in) and a maximum diameter of 58 centimeters (23 in).
The improved R-102A warhead was introduced in 2007 and was primarily designed to bring the R-102 into compliance with modern safety and longevity standards, replacing components identified as likely points of failure with more reliable alternatives and replacing the explosive filler with newer insensitive compounds. Yield remains unchanged but the R-102A is believed to be approximately 10 kilograms lighter than the original R-102, at 145 kilograms (320 lb) while retaining the same external dimensions.
Propulsion and control
While similar to the Astarte II in basic concept and design, the Astarte III uses more modern materials and propellants to increase the missile's propellant fraction and specific impulse. To reduce weight, the Astarte III uses a graphite epoxy casing in place of the Astarte II's para-aramid casing. A new solid fuel mixture was also introduced, using polyethylene glycol as a fuel binder to allow for an increase in solid fuels from 70% in the Astarte II to 75% of the Astarte III's fuel mixture. This solid fuel mixture and case construction method are used for the first two solid rocket stages and the combination of these two technologies accounts for most of the Astarte III's range increase over the Astarte II.
Maneuvering in the first two stages is accomplished through a thrust vector control system which places the missile on its desired trajectory after launch. To reduce aerodynamic friction, the missile uses a deployable aerospike after launch which reduces drag by an estimated 50% and allows the missile to have a more volume-efficient blunt nose fairing.
The third stage retains the liquid fueled design of the Astarte I and II, using a hypergolic mixture of hydrazine and UDMH combined with dinitrogen tetroxide for propulsion. Although liquid fuel third stages have been preferred for Carthaginian SLBMs since the introduction of the Astarte series, ongoing concerns about the carcinogenic properties of hypergolic fuels have led to repeated efforts to replace the third stage with a solid rocket. No such change has been been implemented but the concept remains in consideration for the Astarte IV.
The equipment stage is powered by four onboard gas generators and uses liquid-fuel maneuvering rockets to control its flight during the midcourse phase as well as to maneuver to specified positions to release its RVs. The maneuvering rockets are programmed to avoid firing if doing so will affect a released RV's accuracy. The equipment stage on the Astarte III is smaller and lighter than the stage on the Astarte II thanks to the use of more compact electronics and guidance systems. A modified stage was introduced in the AM2 modernization with even further size reductions, offsetting the increased mass of the Type-X46G MaRV.
Maintenance and support
Basic missile maintenance and storage is conducted at the sixteen missile submarine bases throughout Carthage, such as NSB Nouadhibou. More significant maintenance is carried out at one of four missile maintenance depots under contract with SHAFT ADS. Maintenance of warheads and reentry vehicles is conducted by the Strategic Weapons Directorate under the auspices of the Department of Science, Energy, and Technology, which is responsible for the design and development of the reentry vehicles and the Carthaginian nuclear processing chain. A pool of additional missiles, reentry vehicles, and warheads is kept available to allow for the rapid replacement of faulty components to maintain patrol frequency.
The Astarte III was designed for a service life of 30 years, although life extension programs have the potential to increase this further. With a 30 year service life a replacement missile would need to be developed by 2021 to replace the oldest missiles in inventory, otherwise new missiles would need to be produced or a life extension program approved. Presently, the Astarte IV is in development as of 2016 and is expected to enter service in 2019.
Launch platform
The Astarte III is presently carried by the Type-053N ballistic missile submarine and its successor, the Type-062N. From the start of the program, the Astarte III was designed to fit into the existing launch tubes of the Type-053N and these same tube dimensions were carried over to the Type-062N. Both classes of submarines carry 24 missiles each, and can launch their entire payload in less than five minutes while underway at up to 10 knots. A gas generator is used to expel the missiles from their tubes at launch to avoid igniting the first stage booster within the hull, with ignition occurring after the missile has reached the surface.
Operators
See also
Related lists
Comparable missiles