Tomahawk (missile)
The Tomahawk (/ˈtɒməhɔːk/) Land Attack Missile (TLAM) is a long-range, all-weather, jet-powered, subsonic cruise missile that is primarily used by the United States Navy and Royal Navy in ship and submarine-based land-attack operations.
For other uses, see Tomahawk (disambiguation).Tomahawk
1983–present
2,900 lb (1,300 kg), 3,500 lb (1,600 kg) with booster
- 18 ft 3 in (5.56 m) without booster;
- 20 ft 6 in (6.25 m) with booster
20.4 in (0.52 m)
8 ft 9 in (2.67 m)
Nuclear: W80 warhead (yield 5 to 200 kilotonnes of TNT (21 to 837 TJ)) (retired)[6][7]
Conventional: 1,000 pounds (450 kg) high explosive or submunition dispenser with BLU-97/B Combined Effects Bomb or PBXN
FMU-148 since TLAM Block III, others for special applications
Williams International F107-WR-402 turbofan
using TH-dimer fuel
and a solid-fuel rocket booster
Block II TLAM-N – 1,350 nmi (1,550 mi; 2,500 km)
Block III TLAM-C, Block IV TLAM-E – 900 nmi (1,000 mi; 1,700 km)
Block III TLAM-D – 700 nmi (810 mi; 1,300 km)[8]
Block Vb - 900+nmi, 1035+ miles, 1666+ km (exact range is classified)[9]
RGM/UGM-109B TASM - 250 miles, 460 km[10]
Subsonic; ~Mach 0.74. about 567.7 mph (493.3 kn; 913.6 km/h)
GPS, INS, TERCOM, DSMAC, active radar homing (RGM/UGM-109B)
Developed at the Applied Physics Laboratory of Johns Hopkins University under James H. Walker near Laurel, Maryland, the Tomahawk emerged in the 1970s as a modular cruise missile first manufactured by General Dynamics. The Tomahawk aimed to fulfill the need for a medium- to long-range, low-altitude missile with diverse capabilities. Its modular design allows for compatibility with a range of warheads, including high-explosive, submunitions, and bunker-busters. The Tomahawk can utilize a variety of guidance systems, including GPS, inertial navigation, and terrain contour matching. Over a dozen variants and upgraded versions have been developed since the original design, including air-, sub-, and ground-launched configurations with both conventional and nuclear armaments. The Tomahawk's manufacturing history has seen several transitions. General Dynamics served as the sole supplier in the 1970s. From 1992 until 1994, McDonnell Douglas was the sole supplier of Tomahawks, producing Block II and Block III versions and remanufacturing many Tomahawks to Block III specifications.[12] In 1994, Hughes Aircraft, having purchased General Dynamics' missile division in 1992, outbid McDonnell Douglas to become the sole supplier of Tomahawks.[13][14] A joint venture between Hughes and Raytheon manufactured the missile from 1995 until Raytheon's acquisition of Hughes in 1997, solidifying their position as the sole supplier.[15][16] In 2016, the U.S. Department of Defense purchased 149 Tomahawk Block IV missiles for $202.3 million.[3] As of 2019, Raytheon remains the sole manufacturer of non-nuclear, sea-launched Tomahawk variants.[17]
The variants and multiple upgrades to the missile include:
BGM-109G Ground Launched Cruise Missiles (GLCM) and their truck-like launch vehicles were employed at bases in Europe; they were withdrawn from service to comply with the 1987 Intermediate-Range Nuclear Forces Treaty.[8] Many of the anti-ship versions were converted into TLAMs at the end of the Cold War.[18] The Block III TLAMs that entered service in 1993 can fly 3 percent farther using their new turbofan engines[8] and use Global Positioning System (GPS) receivers to strike more precisely.[18] Block III TLAM-Cs retain the Digital Scene Matching Area Correlation (DSMAC) II navigation system, allowing three kinds of navigation: GPS-only, which allow for rapid mission planning, with some reduced accuracy, DSMAC-only, which take longer to plan but terminal accuracy is somewhat better; and GPS-aided missions that combine DSMAC II and GPS navigation for greatest accuracy.[8] Block IV TLAMs have an improved turbofan engine that allows them to get better fuel economy and change speeds in flight.[8] The Block IV TLAMs can loiter better and have electro-optical sensors that allow real-time battle damage assessment.[8] The Block IVs can be given a new target in flight and can transmit an image, via satcom, immediately before impact to help determine whether the missile is on target and the likely damage from the attack.[8]
A major improvement to the Tomahawk is network-centric warfare-capabilities, using data from multiple sensors (aircraft, UAVs, satellites, foot soldiers, tanks, ships) to find its target. It will also be able to send data from its sensors to these platforms.
Tomahawk Block II variants were all tested during January 1981 to October 1983. Deployed in 1984, some of the improvements included: an improved booster rocket, cruise missile radar altimeter, and navigation through the Digital Scene Matching Area Corellator (DSMAC). DSMAC was a highly accurate rudimentary AI which allowed early low power computers to navigate and precisely target objectives using cameras on board the missile. With its ability to visually identify and aim directly at a target, it was more accurate than weapons using estimated GPS coordinates. Due to the very limited computer power of the day, DSMAC did not directly evaluate the maps, but instead would compute contrast maps and then combine multiple maps into a buffer, then compare the average of those combined images to determine if it was similar to the data in its small memory system. The data for the flight path was very low resolution in order to free up memory to be used for high resolution data about the target area. The guidance data was computed by a mainframe computer which took spy satellite photos and estimated what the terrain would appear like during low level flight. Since this data would not match the real terrain exactly, and since terrain changes seasonally and with changes in light quality, DSMAC would filter out differences between maps and use the remaining similar sections in order to find its location regardless of changes in how the ground appeared. It also had an extremely bright strobe light it could use to illuminate the ground for fractions of a second in order to find its position at night, and was able to take the difference in ground appearance into account.[22]
Tomahawk Block III introduced in 1993 added time-of-arrival control and improved accuracy for Digital Scene Matching Area Correlator (DSMAC) and jam-resistant GPS, smaller, lighter WDU-36 warhead, engine improvements and extended missile's range.[21][23]
Tactical Tomahawk Weapons Control System (TTWCS) takes advantage of a loitering feature in the missile's flight path and allows commanders to redirect the missile to an alternative target, if required. It can be reprogrammed in-flight to attack predesignated targets with GPS coordinates stored in its memory or to any other GPS coordinates. Also, the missile can send data about its status back to the commander. It entered service with the US Navy in late 2004. The Tactical Tomahawk Weapons Control System (TTWCS) added the capability for limited mission planning on board the firing unit (FRU).[24]
Tomahawk Block IV introduced in 2006 adds the strike controller which can change the missile in flight to one of 15 preprogrammed alternate targets or redirect it to a new target. This targeting flexibility includes the capability to loiter over the battlefield awaiting a more critical target. The missile can also transmit battle damage indication imagery and missile health and status messages via the two-way satellite data link. Firing platforms now have the capability to plan and execute GPS-only missions. Block IV also has an improved anti-jam GPS receiver for enhanced mission performance.
Block IV includes Tomahawk Weapons Control System (TTWCS), and Tomahawk Command and Control System (TC2S).[25][26][27]
On 16 August 2010, the Navy completed the first live test of the Joint Multi-Effects Warhead System (JMEWS), a new warhead designed to give the Tomahawk the same blast-fragmentation capabilities while introducing enhanced penetration capabilities in a single warhead. In the static test, the warhead detonated and created a hole large enough for the follow-through element to completely penetrate the concrete target.[28] In February 2014, U.S. Central Command sponsored development and testing of the JMEWS, analyzing the ability of the programmable warhead to integrate onto the Block IV Tomahawk, giving the missile bunker buster effects to better penetrate hardened structures.[29]
In 2012, the USN studied applying Advanced Anti-Radiation Guided Missile (AARGM) technology into the Tactical Tomahawk.[30]
In 2014, Raytheon began testing Block IV improvements to attack sea and moving land targets.[31] The new passive radar seeker will pick up the electromagnetic radar signature of a target and follow it, and actively send out a signal to bounce off potential targets before impact to discriminate its legitimacy before impact.[29] Mounting the multi-mode sensor on the missile's nose would remove fuel space, but company officials believe the Navy would be willing to give up space for the sensor's new technologies.[32] The previous Tomahawk Anti-Ship Missile, retired over a decade earlier, was equipped with inertial guidance and the seeker of the Harpoon missile and there was concern with its ability to clearly discriminate between targets from a long distance, since at the time Navy sensors did not have as much range as the missile itself, which would be more reliable with the new seeker's passive detection and millimeter-wave active radar homing.[33][34] Raytheon estimates adding the new seeker would cost $250,000 per missile.[35] Other upgrades include a sea-skimming flight path.[36][37] The first Block IV TLAMs modified with a maritime attack capability will enter service in 2021.[38]
A supersonic version of the Tomahawk is under consideration for development with a ramjet to increase its speed to Mach 3. A limiting factor to this is the dimensions of shipboard launch tubes. Instead of modifying every ship able to carry cruise missiles, the ramjet-powered Tomahawk would still have to fit within a 21 inches (530 mm)-diameter and 20 feet (6.1 m)-long tube.[32]
In October 2015, Raytheon announced the Tomahawk had demonstrated new capabilities in a test launch, using its onboard camera to take a reconnaissance photo and transmit it to fleet headquarters. It then entered a loitering pattern until given new targeting coordinates to strike.[39]
By January 2016, Los Alamos National Laboratory was working on a project to turn unburned fuel left over when a Tomahawk reaches its target into an additional explosive force. To do this, the missile's JP-10 fuel is turned into a fuel air explosive to combine with oxygen in the air and burn rapidly. The thermobaric explosion of the burning fuel acts, in effect, as an additional warhead and can even be more powerful than the main warhead itself when there is sufficient fuel left in the case of a short-range target.[27][40]
Tomahawk Block V was introduced in 2021 with improvements to navigation and in-flight targeting. Block Va, the Maritime Strike Tomahawk (MST) which allows the missile to engage a moving target at sea, and Block Vb outfitted with the JMEWS warhead for hard-target penetration, will be released after the initial batch of Block V is delivered in March 2021.[41] All Block IV Tomahawks will be converted to Block V standard, while the remaining Block III missiles will be retired and demilitarized.[42]
Tomahawk Block V have longer range and dynamic targeting with the capability to hit vessels at sea (maritime strike role). Raytheon is recertifying and modernizing the missile, extending its service life by 15 years, and resulting in the new Tomahawk Block V series:
In 2020, Los Alamos National Laboratory reported that it would use corn ethanol to produce domestic fuel for Tomahawk missiles, which also does not require harsh acids to manufacture, compared to petroleum-based JP-10.[43]
Each missile is stored and launched from a pressurized canister that protects it during transportation and storage, and also serves as a launch tube.[44] These canisters were racked in Armored Box Launchers (ABL), which were installed on the four reactivated Iowa-class battleships USS Iowa, USS New Jersey, USS Missouri, and USS Wisconsin. The ABLs were also installed on eight Spruance-class destroyers, the four Virginia-class cruisers, and the nuclear cruiser USS Long Beach. These canisters are also in vertical launching systems (VLS) in other surface ships, capsule launch systems (CLS) in the later Los Angeles-class submarine and Virginia-class submarines, and in submarines' torpedo tubes.
All ABL equipped ships have been decommissioned.
For submarine-launched missiles (called UGM-109s), after being ejected by gas pressure (vertically via the VLS) or by water impulse (horizontally via the torpedo tube), a solid-fuel booster is ignited to propel the missile and guide it out of the water.[45]
After achieving flight, the missile's wings are unfolded for lift, the airscoop is exposed and the turbofan engine is employed for cruise flight. Over water, the Tomahawk uses inertial guidance or GPS to follow a preset course; once over land, the missile's guidance system is aided by terrain contour matching (TERCOM). Terminal guidance is provided by the Digital Scene Matching Area Correlation (DSMAC) system or GPS, producing a claimed circular error probable of about 10 meters.
The Tomahawk Weapon System consists of the missile, Theater Mission Planning Center (TMPC)/Afloat Planning System, and either the Tomahawk Weapon Control System (on surface ships) or Combat Control System (for submarines).
Several versions of control systems have been used, including:
On August 18, 2019, the United States Navy conducted a test flight of a Tomahawk missile launched from a ground-based version of the Mark 41 Vertical Launch System.[46] It was the United States' first acknowledged launch of a missile that would have violated the 1987 Intermediate-Range Nuclear Forces Treaty, from which the Trump administration withdrew on August 2 after Russia broke it.[47]
The US Army has successfully launched a Tomahawk from the Typhon missile launcher.[48]
Munitions[edit]
The TLAM-D contains 166 sub-munitions in 24 canisters: 22 canisters of seven each, and two canisters of six each to conform to the dimensions of the airframe. The sub-munitions are the same type of Combined Effects Munition bomblet used in large quantities by the U.S. Air Force with the CBU-87 Combined Effects Munition. The sub-munitions canisters are dispensed two at a time, one per side. The missile can perform up to five separate target segments which enables it to attack multiple targets. However, in order to achieve a sufficient density of coverage typically all 24 canisters are dispensed sequentially from back to front.
[edit]
TERCOM – Terrain Contour Matching. A digital representation of an area of terrain is mapped based on digital terrain elevation data or stereo imagery. This map is then inserted into a TLAM mission which is then loaded onto the missile. When the missile is in flight it compares the stored map data with radar altimeter data collected as the missile overflies the map. Based on comparison results the missile's inertial navigation system is updated and the missile corrects its course. TERCOM was based on, and was a significant improvement on, "Fingerprint," a technology developed in 1964 for the SLAM.
DSMAC – Digital Scene Matching Area Correlation. A digitized image of an area is mapped and then inserted into a TLAM mission. During the flight the missile will verify that the images that it has stored correlates with the image it sees below itself. Based on comparison results the missile's inertial navigation system is updated and the missile corrects its course.
GPRS - The Tomahawk relies on the Global Positioning Recognition System as a guidance mechanism.