America risks entering into a war with the mistaken belief that it has a shield against the enemys missiles when all it has is a sieve. Among the worlds most advanced groundbased air defense systems, the patriot air and missile defense system is in service to the united states and other nations. The missile itself weighs 2200 pounds and its range is 43 miles. Speaking to sputnik, russian military expert andrey golovatyuk, polands drive to purchase the patriot systems can be explained by political rather than defense considerations. The patriot missile failure in dharan, saudi arabia, on february 25, 1991 which resulted in 28 deaths, is ultimately attributable to poor handling of rounding errors. Raytheons new patriot missile software is more first. Officers examining an r17 missile shot down by a patriot mim104 sam system in the desert during operation desert storm. On february 25, 1991 a patriot missile battery failed to intercept an incoming scud missile aimed at an army barracks in dhahran, saudi arabia. F joint missile defence exercises, the largest in 20 i think drilled with arrow israeli missile, patriot, aegis ballistic missile defense system and thaad, integrating all the systems successfully in simulated interceptions of various threats. When the scud missile hit the barracks 28 soldiers lost their lives and 99 were wounded. Prior to the incident, army officials had fixed the software to improve the patriot systems accuracy.
May 29, 2018 on the day of the incident, the system had been operating for more than 100 hours, and the inaccuracy was serious enough to cause the system to look in the wrong place for the incoming missile. During his visit to the plant, president bush inspected the assembly line that produced the patriot air and missile defense system, and sat in a model of the engagement control system, the command post for patriot missile batteries. The missile is launched and guided to the target through three phases. Pac2 missiles operating v34 of the ecs operational software. On february 25, 1991, a patriot missile defense system operating at. According to macierewicz, the patriot will help poland to effectively counteract russias iskander missile systems. The radar antenna scans the sky looking for incoming targets. Us patriot missile systems to be obsolete by the time they. It should be pointed out that the patriot missile was originally designed to be a mobile system and not used as a antiballistic system. Patriot mim104 surfacetoair defense missile system data. Software problems led to system failure at dhahran, saudi arabia. The track via missile guidance system is the basis of the overall system. It turns out that the cause was an inaccurate calculation of the time since boot due to computer arithmetic errors.
Details flaw in patriot missile the new york times. Raytheons new patriot missile software is more firstperson. The computer failure that blinded a patriot missile defense system to an. An investigation discovered a bug in the patriot s tracking software that caused the system s internal clock to drift gradually from the real time. When patriot systems were brought into the gulf conflict, the software was modified several times to. Putting it all together a patriot missile battery operates differently depending on whether it is firing pac2 or pac3 missiles. Software problem led to system failure at dhahran, saudi arabia reported on the cause of the failure. The gao report describes the patriot missile systems operation as follows.
An investigation discovered a bug in the patriots tracking software that caused the systems internal clock to drift gradually from the real time. During the 1991 persian gulf war, the apparent success of the patriot missile defense system served as the official centerpiece of a rhetorical campaign to portray operation desert storm as an unprecedented. The system is built around radar and fast computers. It replaced the nikehercules missile for high and medium altitude air defense in the us army arsenal. The patriot battery at dhahran failed to track and intercept the scud missile because of a software problem in the system s weapons control computer. There was a lot riding on the patriot missile system s success. Included in this report is prefatory background on how the patriot system is designed to work. When the machine had been booted in the recent past, such as every time in testing, the floating point number spent most of its precision to the right of the decimal point. The patriot missile battery is a complete sam system involving the missile, launcher component, carrier vehicle and accompanying fire control section. The purpose of this assignment is to interpret and analyze the need for extremely reliable faultless software in lifecritical situations, using the mim104 patriot tactical air defense missile system with its computercontrolled realtime operating system as an example.
Why the patriot missile might fail americas military the. It is designed to detect, target and then hit an incoming missile that may be no more than 10 to 20 feet 3 to 6 meters long and is typically flying at three to five times the speed of sound. Encyclopedia of espionage, intelligence, and security dictionary. Like many expensive american weapons systems, the patriot missile system has seen a variety of controversy. General accounting office, gaoimtec9226, gao, 1992.
That weapon is the patriot missile system, and as correspondent ed bradley reported last february. Patriot missile defense software problem led to system failure at dhahran, saudi arabia, gao report, general accounting office, washington dc, february 4, 1992. The missile battery did detect the incoming scud missile but in order to check against false alarms it had a serious of checks. Jun 02, 2008 patriot missile defense software problem led to system failure at dhahran, saudi arabia, gao report, general accounting office, washington dc, february 4, 1992. When patriot systems were brought into the gulf conflict, the software was modified several times to cope with the high speed of ballistic missiles, for which the system was not originally designed. The article continues with a readable account of what happened. The rhetoric of patriot missile accuracy in the 1991 persian gulf war. A batterysized element can be emplaced in less than 1 hour. We will look at the operation of the pac2 missile first. Round off errors and the patriot missile the numerical. Raytheon claims 100% success rate for patriot missiles in.
Raytheon was the main contractor of the system, while the missile was developed by martinmarietta. The mim104 patriot is a united states mediumrange surfacetoair missile system manufactured by the raytheon company. A report of the general accounting office, gaoimtec9226, entitled patriot missile defense. General accounting office gao imtec9226 entitled patriot missile defense. The patriot system is comparable to the s300 missile system fielded by russia and many other countries in that both are modern, roadmobile, radarguided sam systems. Pac3 missile launcher, note four missiles in each canister. Apply to instructor, operator, security engineer and more. Learn vocabulary, terms, and more with flashcards, games, and other study tools. First tests of this air defense system took place in 19691970. The pentagon has known for a decade that the patriot cannot distinguish its targets from our own aircraft, says danielle brian, executive director of the project on government oversight, a pentagon watchdog group. The missile system, produced jointly by raytheon and lockheed martin missiles and fire control, was a notable feature in the persian gulf war of 1991 and operation iraqi freedom in 2003. Dhahran air fields and seaports protected by 6 patriot batteries. That weapon is the patriot missile system, and as correspondent ed bradley reported last february, it also does something it was not designed to do bring down friendly aircraft. He recalled that the patriot systems were developed back in 1982, saying that by 2022, russias iskander systems will be significantly modernized.
It was intended to replace the previous nike hercules and hawk air defense missile systems. The mim104 patriot is the most advanced mediumlongrange surfacetoair missile in current operational u. The gao report contains some additional information. Learn about the functions of a patriot missile battery. The united states army redstone arsenal historical. The united states army stock alone totals some 1,100 patriot launcher units. History the first patriot air defence systems were deployed by u.
In other words, khrolenko noted, the patriot systems by themselves do not in any way alter the strategic balance in eastern europe. The patriot is armed with a 200 pound highexplosive warhead detonated by a proximity fuse that causes shrapnell to destroy the intended target. The upgraded patriot system can also destroy incoming aircraft and cruise missiles. Putting it all together patriot missile battery howstuffworks. Hired as a software engineer for the patriot missile defense system training software. With regards to the patriot missile, what caused the failure. Patriot is a groundbased missile defense system which provides airbreathing threat coverage and constitutes the lower tier of a twotiered defense against theater ballistic missiles. Guys, this patriot system is already mothballed, so pay us more money and we will deliver the newest air defense system to you. As part of desert shield patriot batteries were deployed to protect the buildup of allied troops prior to the liberation of kuwait. This time around the patriot missile was going to live up to all the hype, unlike in the first installment of the gulf war when the missiles nearly struck out against iraqi scuds, the softballs of the ballistic missile world. The software error wiki alludes to is that the patriot missile kept track of its internal clock with floating point numbers. Us patriot missile systems to be obsolete by the time.
First, the missiles guidance system turns the patriot toward the incoming missile as that missile flies into the patriot s radar beam. This problem led to an inaccurate tracking calculation that became worse the longer the system operated. Software bug may cause patriot missile errors infoworld. In the 1980s, the patriot was modified to serve as antiballistic missile system for use against shortrange rocket attacks. This is almost the same look and feel as the first patriot system that we rolled out to the army in. In december 2017 the patriot missile defense system failed five times to intercept a houthi missile, which travelled almost km and nearly struck the heart of the kingdom in the capital city. Raytheon company missile systems division is the prime contractor for the patriot system. Patriot uses an advanced aerial interceptor missile and highperformance radar systems.
Patriot missile software problem unc computer science. The mim104 patriot is a surfacetoair missile sam system, the primary of its kind used by the united states army and several allied nations. The first aircraft carrier battle in history duration. The cause of the failure was later found to be a programming. It should be pointed out that the patriot missile was originally designed to be a. An operational patriot battery includes a missile launcher unit, a generator unit, an antennae mast group, a radar unit, and a number of other support components. On the day of the incident, the system had been operating for more than 100 hours, and the inaccuracy was serious enough to cause the system to look in the wrong place for the incoming missile.
Report gaoimtec9226, information management and technology. Software problem led to system failure at dhahran, saudi arabia. Patriot longrange air defense missile system military. Software problem led to system failure at dhahran, saudi arabia provides a nice concise writeup of the problem. The weapon became wellknown after its use in the gulf war. It would seem that 5 countries have this multilayered defence system in various. The most mature hittokill weapon system of the ballistic missile defense system bmds, the patriot weapon system using patriot advanced capability pac3 missiles, is now operational and fielded by the u.
The cause of the failure was later found to be a programming error in the computer embedded in the patriot s weapons control system. Patriot overview the patriot is a surfacetoair guided air and missile defence system currently in use worldwide including in several nato countries germany, greece, the netherlands, spain and the united states. The patriot pac3 missile segment enhancement mse upgrade consists of the pac3 missile, a highly agile hittokill interceptor, the pac3 missile canisters in four packs, a fire solution computer and an enhanced launcher electronics system. The patriot missile battery defending the area never even fired at the incoming scud. To date, the patriot system has been produced in 1,280 launcher units with over 10,000 missiles in circulation. Patriot missile software failure, 28 soldiers died. After the patriots radar detects an airborne object that has the characteristics of a. At least one of these software modifications was the introduction of a subroutine for converting clocktime more accurately into floatingpoint. Oct 31, 2016 pac3 missile launcher, note four missiles in each canister. The martin marietta corporation is a principal subcontractor and assembles the missiles in orlando, florida.
After proven success in development efforts, tasked with creation of new features, encompassing requirements. Army barracks in dhahran, saudi arabia, killing 28 servicemen. The fatal flaws in the patriot missile system corpwatch. This time we will talk about reliability of embedded software in military. Initially designed as an antiaircraft system, patriot gained attention in the 1991 gulf war when it was used as an impromptu defense against iraqi scud missiles. The patriot is a longrange air defense missile system. Why the patriot missile might fail americas military. The time was stored as an integer number in a 24bit register with an accuracy of 110 of a second.
The patriot system, complemented by the new pac3 missile, will remain the armys main tactical airdefense system for some time in the future studies for an advanced surfacetoair missile to supplement and eventually replace the mim. What concerns moscow much, much more is the deployment of the uss aegis missile defense system, armed with sm3 antimissile missiles, on polish territory. The circular pattern on the front of the vertical component is the systems main phased array, consisting of over 5,000 individual elements, each about 39 millimeters 1. The new system did deliver error messages during racecondition events, but the. Apr 17, 2003 this time around it was going to be different. Scud, the range gatean electronic detection device within the radar system calculates an area in the air. A patriot missile battery operates slightly differently depending on whether it is firing pac2 or pac3 missiles.