Small Diameter Bomb
Encyclopedia
The GBU-39 Small Diameter Bomb (SDB) is a 250 pound (113 kg) guided bomb
that is intended to provide aircraft
with the ability to carry a higher number of bombs. Most US Air Force
aircraft will be able to carry (using the BRU-61/A rack) a pack of four SDBs in place of a single bomb of 2000 pounds (907.2 kg).
The initial SDB is expected to be replaced with the Small Diameter Bomb II (SDB-II) / GBU-53/B
.
statute.
Two variants are being developed. One version of the SDB is equipped with a GPS-aided
inertial navigation system
to attack fixed/stationary targets such as fuel
depot
s, bunker
s etc. The second variant (Boeing's GBU-40 or Raytheon's GBU-53 (SDB II)) will include a thermal seeker and radar with automatic target recognition
features for striking mobile targets such as tank
s, vehicle
s, and mobile command posts.
The GBU-39 has a circular error probable
(CEP) of only 5–8 meters, which means it has a 50% probability of hitting its intended target within that distance. CEP is reduced by updating differential GPS
offsets prior to weapon release. These offsets are calculated using an SDB Accuracy Support Infrastructure, consisting of three or more GPS receivers at fixed locations transmitting calculated location to a correlation station at the theatre Air Operations Center. The corrections are then transmitted by Link 16
to SDB-equipped aircraft.
The small size of the bomb allows a single strike aircraft to carry more of the munitions than is possible utilizing currently available bomb units. The SDB carries approximately 38 lb (17 kg) of AFX-757 high explosive
, yet because of its design
it has similar penetration capabilities as the 2000 pounds (907.2 kg) BLU-109. During demonstrations, the SDB has successfully penetrated more than 8 ft (2.4 m) thick reinforced concrete
. It also has integrated "DiamondBack" type wings which deploy after release, increasing the glide time and therefore the maximum range. Its size and accuracy allow for an effective munition with less collateral damage
.
On May 1, 2009, Raytheon announced that it had completed its first test flight of the GBU-53/B Small Diameter Bomb II, which has a data link and a tri-mode seeker built with technology developed for the Precision Attack Missile. And on August 10, 2010 the U.S. Air Force awarded a $450 million contract for engineering and development.
. Future integration is planned for the F-16 Fighting Falcon, F-22 Raptor, F-35 Lightning II, A-10 Thunderbolt II, B-1 Lancer, B-2 Spirit
, and the B-52 Stratofortress. Other aircraft, including UCAV
s, may also receive the necessary upgrades.
GBU-39 began separation tests on the F-22 in early September 2007 after more than a year of sometimes difficult work to integrate the weapon in the weapons bay and carry out airborne captive carry tests.
and the Italian firm Oto Melara
have signed a contract covering the license production of 500 GBU-39s (INS/GPS) and 50 BRU-61/a racks for the Aeronautica Militare
, at a cost of nearly US$34 million.
is developing a version of the SDB I which replaces the steel casing with a lightweight composite
casing and the warhead with a focused blast explosive such as Dense Inert Metal Explosive
(DIME). This should further reduce collateral damage
when using the weapon for pin-point strikes in urban areas.
On 28 February 2008, Boeing celebrated the delivery of the first 50 FLM weapons.
The USAF intends to use the same FLM casing on a weapon of 500 pounds (226.8 kg).
Guided bomb
A guided bomb is a precision-guided munition intended to precisely hit a specific target, and to minimize damage to things other than the target....
that is intended to provide aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
with the ability to carry a higher number of bombs. Most US Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
aircraft will be able to carry (using the BRU-61/A rack) a pack of four SDBs in place of a single bomb of 2000 pounds (907.2 kg).
The initial SDB is expected to be replaced with the Small Diameter Bomb II (SDB-II) / GBU-53/B
GBU-53/B
The GBU-53/B Small Diameter Bomb II is an American air launched, guided bomb.Development was started in 2006 for a class bomb that can identify and strike mobile targets from standoff distances in all weather conditions. It will be integrated on the F-35 Joint Strike Fighter. Its first flight...
.
Development
In 2002, while Boeing and Lockheed Martin were competing to develop the Small Diameter Bomb, Darleen A. Druyun—at that time Principal Deputy Assistant Secretary of the Air Force for Acquisition and Management—deleted the requirement for moving target engagement, which favored Boeing. She was later convicted of violating a conflict of interestConflict of interest
A conflict of interest occurs when an individual or organization is involved in multiple interests, one of which could possibly corrupt the motivation for an act in the other....
statute.
Two variants are being developed. One version of the SDB is equipped with a GPS-aided
Global Positioning System
The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...
inertial navigation system
Inertial navigation system
An inertial navigation system is a navigation aid that uses a computer, motion sensors and rotation sensors to continuously calculate via dead reckoning the position, orientation, and velocity of a moving object without the need for external references...
to attack fixed/stationary targets such as fuel
Fuel
Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air...
depot
Distribution center
A distribution center for a set of products is a warehouse or other specialized building, often with refrigeration or air conditioning, which is stocked with products to be redistributed to retailers, to wholesalers, or directly to consumers. A distribution center is a principal part, the order...
s, bunker
Bunker
A military bunker is a hardened shelter, often buried partly or fully underground, designed to protect the inhabitants from falling bombs or other attacks...
s etc. The second variant (Boeing's GBU-40 or Raytheon's GBU-53 (SDB II)) will include a thermal seeker and radar with automatic target recognition
Automatic Target Recognition
Automatic target recognition , is the ability for an algorithm or device to recognize targets or objects based on data obtained from sensors....
features for striking mobile targets such as tank
Tank
A tank is a tracked, armoured fighting vehicle designed for front-line combat which combines operational mobility, tactical offensive, and defensive capabilities...
s, vehicle
Vehicle
A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....
s, and mobile command posts.
The GBU-39 has a circular error probable
Circular error probable
In the military science of ballistics, circular error probable is an intuitive measure of a weapon system's precision...
(CEP) of only 5–8 meters, which means it has a 50% probability of hitting its intended target within that distance. CEP is reduced by updating differential GPS
Differential GPS
Differential Global Positioning System is an enhancement to Global Positioning System that provides improved location accuracy, from the 15-meter nominal GPS accuracy to about 10 cm in case of the best implementations....
offsets prior to weapon release. These offsets are calculated using an SDB Accuracy Support Infrastructure, consisting of three or more GPS receivers at fixed locations transmitting calculated location to a correlation station at the theatre Air Operations Center. The corrections are then transmitted by Link 16
Link 16
Link 16 is a military tactical data exchange network created and used by the United States and adopted by some of its Allies and by NATO. Its specification is part of the family of Tactical Data Links....
to SDB-equipped aircraft.
The small size of the bomb allows a single strike aircraft to carry more of the munitions than is possible utilizing currently available bomb units. The SDB carries approximately 38 lb (17 kg) of AFX-757 high explosive
Explosive material
An explosive material, also called an explosive, is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure...
, yet because of its design
Design
Design as a noun informally refers to a plan or convention for the construction of an object or a system while “to design” refers to making this plan...
it has similar penetration capabilities as the 2000 pounds (907.2 kg) BLU-109. During demonstrations, the SDB has successfully penetrated more than 8 ft (2.4 m) thick reinforced concrete
Reinforced concrete
Reinforced concrete is concrete in which reinforcement bars , reinforcement grids, plates or fibers have been incorporated to strengthen the concrete in tension. It was invented by French gardener Joseph Monier in 1849 and patented in 1867. The term Ferro Concrete refers only to concrete that is...
. It also has integrated "DiamondBack" type wings which deploy after release, increasing the glide time and therefore the maximum range. Its size and accuracy allow for an effective munition with less collateral damage
Collateral damage
Collateral damage is damage to people or property that is unintended or incidental to the intended outcome. The phrase is prevalently used as an euphemism for civilian casualties of a military action.-Etymology:...
.
On May 1, 2009, Raytheon announced that it had completed its first test flight of the GBU-53/B Small Diameter Bomb II, which has a data link and a tri-mode seeker built with technology developed for the Precision Attack Missile. And on August 10, 2010 the U.S. Air Force awarded a $450 million contract for engineering and development.
Aircraft integration and testing
The SDB is currently integrated on the F-15E Strike EagleF-15E Strike Eagle
The McDonnell Douglas F-15E Strike Eagle is an all-weather multirole fighter, derived from the McDonnell Douglas F-15 Eagle. The F-15E was designed in the 1980s for long-range, high speed interdiction without relying on escort or electronic warfare aircraft. United States Air Force F-15E Strike...
. Future integration is planned for the F-16 Fighting Falcon, F-22 Raptor, F-35 Lightning II, A-10 Thunderbolt II, B-1 Lancer, B-2 Spirit
B-2 Spirit
The Northrop Grumman B-2 Spirit is an American heavy bomber with low observable stealth technology designed to penetrate dense anti-aircraft defenses and deploy both conventional and nuclear weapons. The bomber has a crew of two and can drop up to eighty -class JDAM GPS-guided bombs, or sixteen ...
, and the B-52 Stratofortress. Other aircraft, including UCAV
Unmanned Combat Air Vehicle
An unmanned combat air vehicle or combat drone is an unmanned aerial vehicle that is designed to deliver weapons without an onboard pilot. Currently operational UCAVs are under real-time human control, but future version may enable autonomous operation, for example with pre-programmed route and...
s, may also receive the necessary upgrades.
GBU-39 began separation tests on the F-22 in early September 2007 after more than a year of sometimes difficult work to integrate the weapon in the weapons bay and carry out airborne captive carry tests.
Specifications
- Warhead penetration: 3 feet of steel reinforced concrete
- FuzeFuzeFuze Beverage, commercially referred to as just Fuze , is a manufacturer of teas and non-carbonated fruit drinks enriched with vitamins. Currently the brand consists of five vitamin-infused lines: Slenderize, Refresh, Tea, Defensify, and Vitalize...
: Electronic safe and fire (ESAF) cockpit selectable functions, including air burstAir burstAn air burst is the detonation of an explosive device such as an anti-personnel artillery shell or a nuclear weapon in the air instead of on contact with the ground or target or a delayed armor piercing explosion....
and delayed options.
Cost
Although unit costs were somewhat uncertain as of 2006, the estimated cost for the INS/GPS version was around US$70,000. The cost of the second variant was more uncertain, but tentative estimates were $90,000 per unit or more. BoeingBoeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
and the Italian firm Oto Melara
Oto Melara
Oto Melara is an Italian defence company with factories in Brescia and La Spezia. It was founded in 1905 as a joint venture of Vickers and Terni. During World War I, Vickers Terni produced many weapons with calibre 40 mm and upwards. In 1929 the company was renamed Odero Terni Orlando with the...
have signed a contract covering the license production of 500 GBU-39s (INS/GPS) and 50 BRU-61/a racks for the Aeronautica Militare
Aeronautica Militare
The Italian Air Force is the air force of the Italian Republic. It has held a prominent role in modern Italian military history...
, at a cost of nearly US$34 million.
SDB Focused Lethality Munition (FLM)
Under a contract awarded in September 2006, BoeingBoeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
is developing a version of the SDB I which replaces the steel casing with a lightweight composite
Composite material
Composite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...
casing and the warhead with a focused blast explosive such as Dense Inert Metal Explosive
Dense Inert Metal Explosive
Dense Inert Metal Explosive is an experimental type of explosive that has a relatively small but effective blast radius. It is manufactured by producing a homogeneous mixture of an explosive material and small particles of a chemically inert material such as tungsten...
(DIME). This should further reduce collateral damage
Collateral damage
Collateral damage is damage to people or property that is unintended or incidental to the intended outcome. The phrase is prevalently used as an euphemism for civilian casualties of a military action.-Etymology:...
when using the weapon for pin-point strikes in urban areas.
On 28 February 2008, Boeing celebrated the delivery of the first 50 FLM weapons.
The USAF intends to use the same FLM casing on a weapon of 500 pounds (226.8 kg).
History
- October 2001 – BoeingBoeing Integrated Defense SystemsBoeing Defense, Space & Security formerly known as Boeing Integrated Defense Systems is a unit of The Boeing Company responsible for defense and aerospace products and services. Boeing Integrated Defense Systems was formed in 2002 by combining the former "Military Aircraft and Missile Systems"...
is awarded the SDB contract. - September 2005 – Small Diameter Bomb certified for operational test, evaluation.
- September 2006 – SDB team deliver the first SDBs to the USAF.
- October 2006 – Initial Operational Capability declared for SDB on the F15E.
- October 2006 – First use in combat.
- February 2008 – 1000th SDB I and first 50 FLM delivered.
- September 2008 – Israel receives approval from the US Congress to purchase 1,000 bombs.
- December 2008 – Reportedly used against HamasHamasHamas is the Palestinian Sunni Islamic or Islamist political party that governs the Gaza Strip. Hamas also has a military wing, the Izz ad-Din al-Qassam Brigades...
facilities in the Gaza StripGaza Stripthumb|Gaza city skylineThe Gaza Strip lies on the Eastern coast of the Mediterranean Sea. The Strip borders Egypt on the southwest and Israel on the south, east and north. It is about long, and between 6 and 12 kilometres wide, with a total area of...
, including underground rocket launchers. - January 2009 – Unnamed Boeing official reported to state that they have yet to deliver any SDBs to Israel.
- August 2010 – U.S. Air Force selects Raytheon's GBU-53/B for Small Diameter Bomb II Program.