Editing Joint Direct Attack Munition (section)

===Development===
[[File:US Navy 030319-N-4142G-020 Ordnance handlers assemble Joint Direct Attack Munition (JDAM) bombs in the forward mess decks.jpg|thumb|U.S. Navy sailors attach a JDAM kit aboard the {{USS|Constellation|CV-64}}, March 2003.]]

The [[U.S. Air Force]]'s bombing campaign during the [[Gulf War|Persian Gulf War]] was less effective than initially reported, in part because it had no precision bombs that were accurate in all types of weather. Laser guidance packages on bombs proved exceptionally accurate in clear conditions, but amid airborne [[dust]], [[smoke]], [[fog]], or [[cloud]] cover, they had difficulty maintaining "lock" on the laser designation. Research, development, testing and evaluation (RDT&E) of an "adverse weather precision guided munition" began in 1992. Several proposals were considered, including a radical concept that used GPS.<ref name="OCD"/>

At the time, there were few GPS satellites and the idea of using satellite navigation for real-time weapon guidance was untested and controversial. To identify the technical risk associated with an INS/GPS guided weapon, the Air Force created in early 1992 a rapid-response High Gear program called the "JDAM Operational Concept Demonstration" (OCD) at Eglin Air Force Base. [[Honeywell]], Interstate Electronics Corporation, Sverdrup Technology, and [[General Dynamics]] were hired to help the USAF 46th Test Wing demonstrate the feasibility of a GPS weapon within one year. The OCD program fitted a GBU-15 guided bomb with an INS/GPS guidance kit and on 10 February 1993, dropped the first INS/GPS weapon from an F-16 on a target {{convert|88000|ft|km}} downrange. Five more tests were run in various weather conditions, altitudes, and ranges.<ref name="OCD">INS/GPS Operational Concept Demonstration (OCD) High Gear Program, IEEE Aerospace and Electronic Systems Magazine, 8 August 1994.</ref> The OCD program demonstrated a {{convert|11|m|ft|order=flip|adj=on}} [[Circular Error Probable]] (CEP).

[[File:First gps weapon OCD.jpg|thumb|The first flight test of the first GPS-guided weapon resulted in a direct hit on a target at [[Eglin Air Force Base]] on 10 February 1993.]]

The first JDAM kits were delivered in 1997, with operational testing conducted in 1998 and 1999. During testing, over 450 JDAMs were dropped achieving a system reliability in excess of 95% with a published accuracy under {{convert|10|m|ft|order=flip|adj=on}} CEP.<ref name="Boeing PR">{{Cite web|last=Davis|first=Charles H.|title=JDAM: The Kosovo Experience and DPAS|publisher=The Boeing Company|date=19 April 2000|url=http://guidebook.dcma.mil/38/dpas/12DavisPres.pdf|access-date=2007-09-01|url-status=dead |archive-url=https://web.archive.org/web/20070926192856/http://guidebook.dcma.mil/38/dpas/12DavisPres.pdf|archive-date=26 September 2007}}</ref> In addition to controlled parameter drops, the testing and evaluation of the JDAM also included "operationally representative tests" consisting of drops through clouds, rain and snow with no decrease in accuracy from clear-weather tests. In addition, there have been tests involving multiple weapon drops with each weapon being individually targeted.<ref>{{Cite web |date=17 September 2003 |title=U.S. Air Force B-2 Bomber Drops 80 JDAMS in Historic Test |url=https://boeing.mediaroom.com/2003-09-17-U.S.-Air-Force-B-2-Bomber-Drops-80-JDAMS-in-Historic-Test |url-status=live |archive-url=https://web.archive.org/web/20230926191112/https://boeing.mediaroom.com/2003-09-17-U.S.-Air-Force-B-2-Bomber-Drops-80-JDAMS-in-Historic-Test |archive-date=26 September 2023 |access-date=2 September 2007 |website=Boeing}}</ref>

[[File:Ex-Schenectady (LST-1185) sinking.jpg|thumb|right|Ex-[[USS Schenectady (LST-1185)|''Schenectady'' (LST-1185)]] damaged by seven 2,000-pound JDAMs during USAF exercise Resultant Fury in November 2004.]]
JDAM and the [[B-2 Spirit]] stealth bomber made their combat debuts during [[Operation Allied Force]]. The B-2s, flying 30-hour, nonstop, round-trip flights from [[Whiteman Air Force Base]], [[Missouri]], delivered more than 650 JDAMs during Allied Force. An article published in the ''Acquisition Review Journal'' in 2002 cites that "during Operation Allied Force ... B-2s launched 651 JDAMs with 96% reliability and hit 87% of intended targets..."<ref name="ARQJDAM">{{cite journal |last=Myers |first=Dominique |year=2002 |title=Acquisition Reform-Inside The Silver Bullet |url=http://www.dau.mil/pubs/arq/2002arq/MyersFL02.pdf |url-status=dead |journal=Acquisition Review Journal |volume=IX |issue=Fall 2002 |pages=312–322 |archive-url=https://web.archive.org/web/20070926194415/http://www.dau.mil/pubs/arq/2002arq/MyersFL02.pdf |archive-date=26 September 2007 |access-date=1 September 2007}}</ref> Due to the operational success of the original JDAM, the program expanded to the {{convert|500|lb|kg|adj=on}} Mark 82 and {{convert|1000|lb|kg|adj=on}} [[Mark 83 bomb|Mark 83]], beginning development in late 1999. As a result of lessons from [[Operation Enduring Freedom]] and [[Operation Iraqi Freedom]], both the [[US Navy]] and US Air Force pursued improvements to the kits such as better GPS accuracy as well as a precision seeker for terminal guidance for use against moving targets.

JDAM bombs are inexpensive compared to alternatives such as [[cruise missile]]s. The original cost estimate was $40,000 each for the tail kits; however, after competitive bidding, contracts were signed with McDonnell Douglas (later [[Boeing]]) for delivery at $18,000 each. Unit costs, in current-year dollars, have since increased to $21,000 in 2004 and $27,000 by 2011.<ref>{{cite web|title=Air Force Justification Book Procurement of Ammunition, Air Force|url=http://www.saffm.hq.af.mil/shared/media/document/AFD-110211-035.pdf|work=Department of Defense Fiscal Year (FY) 2012 Budget Estimates|publisher=US Air Force|access-date=29 December 2011|url-status=dead |archive-url=https://web.archive.org/web/20111215152358/http://www.saffm.hq.af.mil/shared/media/document/AFD-110211-035.pdf|archive-date=15 December 2011}}</ref> To the cost of the tail kit should be added the costs of the Mk80-series iron bomb, the fuze and proximity sensor which bring the overall weapon cost to about $30,000. For comparison, the newest Tomahawk cruise missile, dubbed the [[BGM-109 Tomahawk|Tactical Tomahawk]], costs nearly $730,000 (FY 2006).<ref>{{Cite web |last=Grier |first=Peter |date=1 September 2006 |title=The JDAM Revolution |url=https://www.airandspaceforces.com/article/0906jdam/ |url-status=live |archive-url=https://web.archive.org/web/20230531154253/https://www.airandspaceforces.com/article/0906jdam/ |archive-date=31 May 2023 |website=Air & Space Forces Magazine}}</ref><ref>{{Cite web |title=BGM-109 Tomahawk - Tomahawk Variants |url=https://www.globalsecurity.org/military/systems/munitions/bgm-109-var.htm |url-status=live |archive-url=https://web.archive.org/web/20230326081404/https://www.globalsecurity.org/military/systems/munitions/bgm-109-var.htm |archive-date=26 March 2023 |website=Global Security}}</ref>