MIM-104 Patriot
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The MIM-104 Patriot is a United States medium-range surface-to-air missile system manufactured by the Raytheon Company. It replaced the Nike-Hercules Missile for high and medium altitude air defense in the US Army arsenal. The weapon became well-known after its use in the Gulf War. Like many expensive American weapons systems, the Patriot missile system has seen a variety of controversy concerning its performance in combat.
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Introduction
The MIM-104 Patriot missile was conceived in the 1960s, in development since 1976 for anti-aircraft use, and was deployed in 1984. In 1988 it was adapted for a more demanding anti-ballistic missile role as PAC (Patriot Advanced Capability). The Patriot system is built around a combined transporter-launcher carrying 32 missiles (80 in the case of PAC-3 systems). The missiles are carried in batches of four in a M-901 container; transport is provided by a M-860 semi-trailer. Together with the missiles a separate trailer transports the MSQ-104 engagement control station.
The system uses Track-via-Missile guidance and active radar terminal homing. The missile itself is 5.31 meters-long, weighing 900 kg and powered by a solid-propellant rocket motor at speeds up to Mach 5. It is armed with a 91 kg blast-fragmentation warhead with a proximity fuse. Effective range is around 70 km. Patriot systems have been sold to Israel, Germany, the Netherlands and Belgium.
Usage during the 1991 Gulf War
Trial by fire
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Prior to the Persian Gulf War missile defense was an unproven concept in war. The Patriot was assigned to shoot down incoming Iraqi Scud or Al Hussein missiles launched at Israel and Saudi Arabia. The first combat use of Patriot occurred 18 January 1991 when it successfully intercepted and destroyed an Iraqi Scud missile fired at Saudi Arabia. This was the first time an air defense system destroyed a hostile theatre ballistic missile (TBM).
Failure at Dharan
On February 25, 1991 an Iraqi Scud hit the barracks in Dharan, Saudi Arabia, on killing 28 soldiers from the US Army's 14th Quartermaster Detachment.
A government investigation revealed that the failed intercept at Dharan had been caused by a software error in the system's clock. The Patriot missile battery at Dharan had been in operation for 100 hours, after which time the clock had drifted by one third of a second, equivalent to a position error of 600 meters. The radar system detected the Scud and predicted where to look for it next, but because of the time error, looked in the wrong part of the sky and found no missile. With no missile, the initial detection was assumed to be a false alarm and the missile was removed from the system. The Israelis had identified the problem and informed the US Army and the Patriot Project Office (the software manufacturer) on February 11, 1991. The Israelis recommended rebooting the Patriot system's computers as a workaround; however, Army officials did not understand how often they needed to reboot the system. The manufacturer supplied updated software to the Army on February 16. The updated software arrived the day after the Scud struck the Army barracks.
Success rate vs accuracy
The U.S. Army claimed an initial success rate of 80% in Saudi Arabia and 50% in Israel. Those claims were eventually scaled back to 70 and 40 percent.
On April 7, 1992 Theodore Postol of the Massachusetts Institute of Technology, and Reuven Pedatzur of Tel Aviv University testified before a House Committee stating that, according to their independent analyses, the Patriot system had a success rate of below ten percent, and perhaps even a zero success rate.
On that same day Charles A. Zraket of the Kennedy School of Government, Harvard University and Peter D. Zimmerman of the Center for Strategic and International Studies testified about the calculation of success rates and accuracy in Israel and Saudi Arabia and discounted many of the statements and methodologies in Postol's report.
- Success Rate - the percentage of Scuds destroyed or deflected to non-populated areas
- Accuracy - the percentage of hits out of all the Patriots fired
It is important to note the difference in terms when analyzing the performance of the system during the war.
According to Zimmerman, in accordance with the standard firing doctrine on average four Patriots were launched at each incoming Scud — in Saudi an average of three Patriots were fired. If every Scud were deflected or destroyed the success rate would be 100% but the Accuracy would only be 25% and 33% respectively.
Both testimonies state that part of the problems stem from its original design as an anti-aircraft system. At the time, the system fired proximity missiles which arrive near the target and explode, either destroying or disabling the target. These missiles were fired at the target's center of mass. With aircraft this was fine, but with the high speeds of Scuds and the location of the warhead the Patriot would most often hit close to the tail of the Scud.
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The Iraqi redesign of the Scuds also played a role. Iraq had redesigned its Soviet-style Scuds to be faster, but the changes weakened the missile and it was more likely to break up upon re-entering the atmosphere. This presented a larger number of targets as it was unclear which piece contained the warhead.
What all these factors mean, according to Zimmerman, is that the calculation of "Kills" becomes more difficult. Is a kill the hitting of a warhead or the hitting of a missile? If the warhead falls into the desert because a Patriot hit its Scud, is it a success? What if it hits a populated suburb? What if all four of the engaging Patriots miss and the warhead falls because the Scud broke up?
According to the Zraket testimony there was a lack of high quality photographic equipment necessary to record the interceptions of targets. Therefore, Patriot crews recorded each launch on videotape, and damage assessment teams recorded the Scud debris that was found on the ground. Crater analysis was then used to determine if the warhead was destroyed before the debris crashed or not. Furthermore, part of the reason for the thirty percent improvement in success rate in Saudi Arabia compared to Israel is that the Patriots merely had to push the incoming Scud missiles away from military targets in the desert or disable the Scud's warhead in order to avoid casualties, while in Israel the Scuds were aimed directly at cities and civilian populations. The Saudi Government also censored any reporting of Scud damage by the Saudi press. The Israeli Government did not institute the same type of censorship. Furthermore, the Patriot's success rate in Israel was examined by the IDF (Israel Defense Forces) who did not have a political reason to play up the Patriot's success rate and even had reasons to downplay the Patriot's success rate. The IDF counted any Scud that exploded on the ground (regardless of whether or not it was diverted) as a failure for the Patriot. Meanwhile, the U.S. Army who had many reasons to support a high success rate for the Patriots, examined the performance of the Patriots in Saudi Arabia.
A Canadian Broadcasting Corporation documentary quotes the former Israeli Defense Minister as saying the Israeli government was so dissatisfied with the performance of the missile defense, that they were preparing their own military retaliation on Iraq regardless of US objections. That response was cancelled only with the cease fire with Iraq.
Psychological effects of the system
Saddam had vowed to rain down missiles on Israel with hopes of provoking Israel to attack, and possibly bringing other Arab states into the conflict on Iraq's side. Israel was concerned over the use of biological or chemical agents in the Scuds. The Patriot gave the Israeli government a way to calm their people in the early days of the war.
During the conflict in Israel two people were killed and several hundred were injured.
Patriot upgrades
As of 2002, Israel currently uses the Patriot as part of a two-tier anti-ballistic missile defense system, with the Arrow missile in the role of high-altitude interceptor and the Patriot for point defense. Patriots are deployed around Israel's nuclear reactor and nuclear weapons assembly point at Dimona.
The PAC-2 or PATRIOT ADVANCED CAPABILITY -2 is, like the original (sometimes denoted as PAC-1), a proximity device that explodes near the target. It has greater range than the PAC-1.
The GEM is an addition to the PAC2 that allows the missile to correct itself in-flight, originally all corrections had to be sent to the missile by the ground control center.
The PAC-3 missile is smaller than the PAC-2 missile and is more accurate. This is because it is a hit-to-kill missile that aims for the warhead. It contains no explosives but uses its kinetic energy to detonate the warhead. Because of the reduced size, a launcher trailer can carry sixteen PAC-3 missiles (four canisters with four missiles per canister) rather than the four missiles carried by the PAC-1 or PAC-2 trailers carry (four canisters with one missile per canister). Not only is the PAC-3 system more accurate, but more missiles can be fired at each target if necessary to increase the chances of successful interception.
The PAC-3 variant is expected to receive newer, more advanced rocket motors that allow for up to a 50% increase in range bringing its maximum range from about 150 km (93 miles) to nearly 300 km (186 miles).
The vast majority of improvements have been to the Patriot's software. Raytheon has created a software only upgrade that allows the PAC-1 to target incoming MLRS attacks. This was done primarily as a counter to North Korea's heavy build-up of the MLRS capable units. Secondly it gives both the military and Raytheon a marketing tool to sell the system and stockpiled PAC-1s (left over from the Iraq Containment Operations in Saudi Arabia and Kuwait from 1991 to 2003) to South Korea.
Usage during the 2003 invasion of Iraq
During the Iraq war of 2003, Patriot batteries succeeded in shooting down several Iraqi missiles, but mistook a returning RAF Tornado GR4 for an Iraqi missile, destroying it and killing both members of the crew. Immediately after the incident it was claimed that the RAF crew had failed to switch on their IFF beacon. However a US journalist embedded with the army unit operating the Patriot battery said the "army Patriots were mistakenly identifying friendly aircraft as enemy tactical ballistic missiles."
Echo Battery, 2nd Battalion, 43rd Air Defense Artillery fired and successfully engaged with the first PAC-3 missiles in combat. The Patriot also hit several non-Scud missiles launched against Saudi Arabia and Kuwait, including anti-ship missiles like the Sparrow. These missiles arc low to the ground (50km) compared to the Scud missiles which enter the stratosphere, allowing much less time to target and intercept the missile. As a result several of the missiles did get through but their effect was minimal.
PATRIOT naming
According to the on-line U.S. Army Fact File[1] (http://www.army.mil/fact_files_site/patriot/index.html), PATRIOT is an acronym for "Phased Array Tracking Intercept of Target". Other sources provide a slightly different version, "Phased Array Tracking to Intercept of Target". Some sources [2] (http://www.globalsecurity.org/space/systems/patriot.htm) claim that "PATRIOT" is not really an acronym at all. In most cases, official Army websites [3] (http://peoamd.redstone.army.mil/NEW/project-offices/PATRIOT/index.htm) and other web sites [4] (http://www.raytheon.com/products/static/node3832.html) simply use "PATRIOT" or "Patriot" without any reference to an acronym.
See also
External links and references
- Official Army PATRIOT web site (http://peoamd.redstone.army.mil/NEW/project-offices/PATRIOT/index.htm)
- Official Raytheon (missile contractor) PATRIOT web site (http://www.raytheon.com/products/static/node3832.html)
- Patriot MIM-104 (http://www.fas.org/spp/starwars/program/patriot.htm)
- GAO Report on Failed Dharan Intercept (http://www.fas.org/spp/starwars/gao/im92026.htm)
- Theodore Postol and George M. Lewis's Report on Patriot Effectiveness During the Gulf War (http://www.fas.org/spp/starwars/docops/pl920908.htm)
- Testimony of Charles A. Zraket (http://www.fas.org/spp/starwars/congress/1992_h/h920407m.htm)
- Testimony of Peter D. Zimmerman (http://www.fas.org/spp/starwars/congress/1992_h/h920407z.htm)de:MIM-104 Patriot