Small Diameter Bomb The GBU - 39 Small Diameter Bomb ( SDB ) is a precision - guided glide 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 . The Small Diameter Bomb II ( SDB - II ) / GBU - 53 / B scheduled to enter production in January 2014 will add a tri - mode seeker ( radar , infrared , and semiactive laser ) to the INS and GPS guidance of the original SDB . 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 interest 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 , vehicles , and mobile command posts . The GBU - 39 has a circular error probable ( CEP ) of 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 of AFX - 757 high explosive . 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 . Aircraft integration and testing . The SDB is currently integrated on the F - 15E Strike Eagle and on the Panavia Tornado . 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 . Ground - launched SDB . Boeing is modifying the Small Diameter Bomb with a rocket motor to be launched from ground - based missile systems such as the M270 MLRS . With the Army demilitarizing cluster munitions from M26 rockets , the company says a special adapter case could reuse the rocket to launch the SDB . After the motor launches it to a high enough altitude and speed , the wings will deploy and glide the bomb to its target . The company believes it can fill a gap for long - range precision fires while using its smaller warhead to save larger rocket munitions for strategic targets . While typical MLRS systems follow a ballistic trajectory , the rocket - launched SDB can be launched to an altitude and glide on a selected trajectory . Boeing is planning on a demonstration in 2014 . LSDB . In June 2013 , the Air Force announced it would award Boeing a contract to develop and test a laser guided version of the SDB . Called the Laser Small Diameter Bomb ( LSDB ) , it is based on JDAM technology and can hit moving and maritime targets . Boeing says the LSDB can be built at a lower cost than the planned Raytheon GBU - 53 / B SDB II , as it will use the same semi - active laser sensor as the JDAM . However , Boeing admits that it does not have the capability to engage targets in zero - visibility weather , as it lacks the SDB II ' s millimeter wave radar . 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 . Boeing 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 . SDB Focused Lethality Munition ( FLM ) . Under a contract awarded in September 2006 , Boeing 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 .