Iran’s missile capability
An interview with Uzi Rubin
On March 14, 2006, the Wisconsin Project’s IranWatch.org web site spoke with Mr. Uzi Rubin, former head of Israel’s “Arrow” missile defense program. Mr. Rubin, who is an aerospace engineer and missile expert, described Iran’s latest effort to field a fleet of nuclear capable ballistic missiles. He also evaluated the threat that Iran’s missiles present to Israel and to U.S. forces, and the ability of missile defenses to block an Iranian attack.
The following is an edited transcript of our conversation.
Iran Watch (IW): Iran’s “Shahab-3” missile has been cited as a threat to Israel. What do you estimate to be its range and accuracy?
Uzi Rubin (UR): The Shahab-3 is really the North Korean Nodong missile, which Iran imported. Its range is thought to be 1,300 km. This range makes a lot of sense for Iran, because if you look at the minimum distance from Iran to Israel, and you look at where you can base a missile system in Iranian territory not too close to the border, you need about 1,300 km. So it makes sense.
However, about two years ago the Iranians revealed a new variation of the Shahab-3 missile, which looks slightly longer. It has a different front end, a “baby bottle” shape. For this version of the missile, the Iranians quoted a range of 2,000 km. How they achieved it—what precisely gave the missile that extra range—is hard to say, but there is no reason to doubt the statement. So, I’d say that Iran may well have a Shahab-3 with a range of 2,000 km.
Such a missile is guided only through the boost phase, which puts limitations on its accuracy. Generally speaking, there is an upper limit on the accuracy of this kind of missile. If you want to improve on that limit you need to guide the missile through the rest of the flight, through the mid-coast phase and the reentry phase. With these kinds of missiles, the best thing you can do in terms of accuracy is perhaps one tenth of one percent of the range. Let’s say the Shahab-3 flies 2,000 kilometers, then the circular error probable (CEP) is about two kilometers. Not more than two kilometers and not less than one kilometer.
IW: How do you think they achieved that? With bigger fuel tanks?
UR: Yes. The Iranians moved the instruments section in order to free more volume for fuel. The missile is also constructed differently, in order to make room for more fuel and oxidizer. Iran may also have decreased the size of the payload. All this could provide a 700 km increase, to about 2,000 km. It is feasible.
IW: Would you say that this is the maximum range Iran can achieve with this missile?
UR: I think so. If Iran wants to extend the range, it would need a different propulsion system.
On that point, there are reports that Iran bought a new missile recently from North Korea. The German magazine Bild published an article in January saying that Iran bought 18 missiles, known as the BM-25, from North Korea. The missile in question would be better than the Shahab-3. It is a replication or variation of the old Soviet SS-N-6, a submarine launched ballistic missile.
This missile has storable liquid fuel, which provides better performance. The Soviets claimed it had a range of 2,500 km, with one variation having a range of 3,000 km. So according to the report the Iranians could have in their hands now a 3,000 km range missile.
IW: How credible do you consider this report?
UR: It’s plausible. The report quotes intelligence officials and it quotes the exact number of missile systems that were bought. The Prime Minister of South Korea had also claimed that North Korea has missiles with a range of at least 3,000 km.
IW: Is the BM-25 a staged missile?
UR: No. It looks very much like the U.S. Polaris. It dates from the 1960s but it was in service until the 1990s. The missiles were onboard Soviet Yankee class submarines. The range started at 2,500 km and went up to 3,000 km. It eventually had multiple warheads. In Russia, it was called the R 27. It was the first strategic ballistic missile on a Russian boomer.
IW: This is a single-stage, liquid-fuel submarine-launched missile. Is it going to be more accurate than the Shahab?
UR: Not necessarily. Again, I would say that there is a limitation to this kind of technology, in that it doesn’t correct trajectory after the boost phase. There is great difficulty in making the precision better than one tenth of one percent of the range. It’s an imprecise weapon that can hit only very big targets or can cause damage to a smaller target only with a very big warhead.
IW: Would it be difficult to get a chemical warhead to work on a missile like this?
UR: Yes, it would be quite tricky. Iran could mimic the Iraqis and put a unitary chemical warhead on its missile. It would hit the ground and splash and very little of it would vaporize. The effect would be deadly but would be very limited in area. What you want to do is have it disperse when it is still in the air, but that is very tricky with a missile flying this fast. A 2,000 km range missile flies about 4 km per second. So reentry is quite fast.
IW: What do you think is the diameter of the Shahab-3?
UR: Probably somewhere between 1.2 and 1.4 meters.
IW: Would this be large enough for a nuclear warhead?
UR: Well, a nuclear warhead would be on the front end of the missile. The old model of the Shahab-3 is shaped like a cone. The new model of the Shahab-3 has a tri-cone design, the “baby bottle” design. On this newer one, the diameter is smaller. But I am not an expert on nuclear warheads, so I really don’t know if the Iranians will have trouble putting a nuclear warhead on this missile. I assume that if you are looking at the older type of Shahab with the single cone, the diameter would vary up to 1.2 to 1.4 meters at the base. One could possibly fit a nuclear weapon there.
But remember the BM-25. This is a nuclear missile. It was designed as a nuclear missile and there is no other warhead for this than a nuclear warhead. So, if the reports are true, Iran has its hands on at least two nuclear capable missiles with sufficient diameters for the type of nuclear weapons that the Soviets had in the 1960s. The diameter of the BM-25, I think, is 1.5 meters.
IW: Is the Shahab-3 widely deployed? Who controls it?
UR: It is controlled by a combination of the Iranian Revolutionary Guards and the Iranian Air Force. There was a big induction ceremony in July 2003 for the missile and during that ceremony you saw officials in Revolutionary Guard and Air Force uniforms participating. If the Revolutionary Guards are involved that means it’s a political weapon controlled by the supreme authority.
IW: How would you estimate the inventory?
UR: The Iranians say they are manufacturing the missile and that they are accelerating production from two per month to ten or twelve per month. I doubt that it could be dozens per month. But even a few per month still gives you many per year. In their military parades, they never display more than six missiles at the same time. In September 2003 they displayed six Shahab-3 missiles in the annual Martyr’s Week parade. In 2004 they displayed only two Shahab-3 missiles. And in September 2005 they again displayed six Shahab-3 missiles. If the Iranians have a lot of missiles, why don’t they parade more of them? Why does the number paraded remain so low? Nevertheless, I think it would be prudent to assume that they have at least several dozen in the arsenal now.
Of course, there is also the question why Iran would need so many missiles, because the limiting factor is the launchers, not the missiles. Missiles are like ammunition, launchers are like guns. So you need to increase the number of guns, not only the amount of ammunition.
IW: Does Iran still need outside help to produce the Shahab-3 missile?
UR: Iran seems to have mastered the production of the Shahab and its liquid fuel technology. Iran is now moving to solid fuel technology. In the last few months, there have been reports about Iranian buyers being caught trying to smuggle production equipment to Iran from Europe. There was one case in Germany and another in Russia. When you look at what was being smuggled, it suggests that they’re looking for equipment to make solid propellant rockets. For instance, they’re looking for high-power x-ray machines, which are needed for non-destructive testing of solid rocket motors, not liquid rocket motors. This is equipment that Iran would want to buy because it’s very difficult to develop on your own.
This coincides with a statement by then-Iranian Defense Minister Ali Shamkhani, about a year ago, that Iran is moving into solid fuel propelled rockets. And this would mean a new missile because you cannot just put a solid fuel motor on the Shahab, you have to redesign the whole missile. Iran will eventually be able to make Shahab-like missiles using solid fuel technology. To summarize, I think they are able to produce the Shahab independently now, but they are not yet independent in the production of solid propellant missiles.
IW: Do you know of a solid propellant rocket that Iran has fielded?
UR: Iran deploys small, unguided rockets, but not larger ones. Not, for instance, missiles with a one meter diameter or bigger. This is a completely different technology and for that Iran needs special equipment to make the casings, to inspect the motors, and for other things. I have no doubt that the Iranians are moving in this direction, because they are emulating Pakistan’s missile development. If you look at the Pakistani missile program, you see two parallel programs: the Ghouri and the Shaheen. There are two different missile-making organizations. One makes strategic liquid propellant rockets and one makes strategic solid propellant rockets. I think the Iranians are looking to Pakistan and trying to do the same thing. In Pakistan, the solid fuel technology comes from China and the liquid fuel technology from North Korea. It may be the same in Iran.
IW: The Shahab-3 is a mobile missile; how vulnerable is it?
UR: I don’t think it is particularly vulnerable. The lesson from Iraq in 1991 is that it’s very easy to hide mobile launchers. They’re not much bigger than trucks. They can hide anywhere.
IW: In effect, you’re saying that if these missiles are armed with nuclear warheads, it would be very hard to destroy them in an air strike.
UR: Yes. It would be prudent to assume that as with Iraq in 1991, it would be very hard to destroy the Shahab with an air strike. The launchers are slightly less mobile than Iraqi Scud launchers, because they are not on self-propelled launchers. Instead, they are attached to commercial Mercedes tow trucks to which the launcher is hitched. But it’s still quite mobile.
IW: Where is Iran getting the mobile launchers?
UR: The trucks are regular commercial Mercedes tow trucks. The Iranians are building the semi-trailers themselves. They are also building their own launchers, including the hydraulics, and all the control systems. If you look at the pictures, the control cabin looks like it’s modeled on Russian control cabins.
IW: Who is vulnerable to Iranian missile strikes?
UR: A 2,000 km range covers the entire Middle East. It includes Israel, Egypt, part of North Africa, all of Saudi Arabia, some of Eastern Europe, and part of Russia. I think even Greece and the Balkans are covered with a 2,000 km range missile. But remember, if they have a 3,500 km missile then most of Europe is covered.
IW: How effective do you think U.S. and Israel missile defenses are against this threat?
UR: They are quite effective. The U.S. is now starting to deploy national missile defense, but this system is not designed against the Shahab. It’s designed against much larger missiles, intercontinental range missiles. The U.S. is starting to deploy a naval system using the Aegis missile defense system, called the Standard Missile 3 (SM3). This system has been extensively tested and it has been effective. Of course, Israel has the Arrow. Those two systems, the Aegis and the Arrow, can interoperate. The U.S. and Israel have been working together on this—on the ability to engage the same target together.
IW: Can the Arrow stop the Shahab-3?
UR: Yes, of course. The Arrow was designed against the Shahab-3. That was my first point of reference when we started the Arrow program in the early 1990s. I was authorized to speak on the record in 1993 and to say that Iran’s 1,300 km missile—we did not know the name at that time—was one of our reference threats in developing the Arrow system.
IW: Have there been successful tests of the Arrow that support the claim that the Arrow can stop the Shahab-3?
UR: Yes. In the latest test of the Arrow on December 2, 2005, the Arrow targeted a missile simulating a separated Shahab-3 warhead and blasted it out of the sky. And two years ago we had two tests in California. The first test was against a real Scud missile, and we had no problem shooting it down. While this was not a Shahab, it gave us a lot of confidence in the Arrow.
And the missile defense version of the U.S. Navy Aegis system is being deployed. I think the U.S. has ten ships scheduled to be equipped with new model SPY radar. The SM3’s are rolling off the assembly line right now and are being fitted to ships. And of course the United States has the PAC3, which is completely operational and which proved its capability during the Iraq war in 2003. It hit every single target that it engaged. The success was not hailed because of the success of the rest of the war, but this time Patriot proved itself.
IW: Are there a sufficient number of Arrows to counter the inventory of Shahab-3s that Iran might have?
UR: As the former head of the program, I would say that we never have enough Arrows. We have a reasonable number of them. Technically, we can hit the Shahab-3 and block an attack. Whether we can block an entire attack would depend on the size of the attack. If Iran fired thousands of missiles we couldn’t, obviously, but I don’t expect Iran to fire thousands of missiles.
IW: Iran has never hidden the fact that it has an active ballistic missile program. How would you assess the quality of intelligence on this program?
UR: This is like asking: when did you stop beating your wife. Any answer is revealing. Any answer I give would be classified. But let me say this: Unlike the Iraqis, the Iranians are showing off a lot of stuff. Until recently, the policy was transparency: they talk a lot, they publish a lot and they parade a lot. And you can learn a lot from that. They’ve grown cautious in the last year or so. But until recently, you could get a very good idea of what they were doing just from media and other open sources.
IW: There used to be reports about Iran’s work on the Shahab-4. What is the status of that missile?
UR: There are questions about the Shahab-4. A few years ago, Iran issued a statement that the Shahab-3 would be the last Shahab version and that Iran wouldn’t make any follow-on version with a longer range. Obviously this was a statement to placate the Europeans. Iran didn’t want the Europeans to worry because any follow-on Shahab would have covered Europe. Recently, I saw an Iranian statement saying the Shahab-4 exists but that it is a satellite launcher and not a ballistic missile. This coincides with other statements by Iran that it is building a satellite launcher to launch its own satellites. This is something I’ve been predicting for a long time. Once you have a big ballistic missile, with some modification, you can make a satellite launcher from it. Satellite launching is a great boost to national pride and national capability. And a satellite launcher is basically a covert intercontinental missile.
IW: Is the Shahab-4 just a bigger single-stage rocket? Or do you think Iran is going towards staging?
UR: No doubt about it, Iran is going towards staging. There is no easy way
to launch satellites with one stage. And Iran has a very close relationship
to North Korea. Remember what was called (incorrectly) the Taepodong, but what
the North Koreans called the Paektusan. This was the name of the satellite
launcher North Korea tested in 1998. The first stage was like a Nodong and
the second stage was like a Scud, and it probably had a small, Chinese-made,
solid propellant rocket as the third stage. If North Korea did it in 1998,
I don’t see why the Iranians cannot do it next year. In fact, I wonder
why they haven’t done it already. Iran is buying missiles from North
Korea and there are North Korean technicians in Iran. The first stage of Iran’s
satellite launcher would obviously be based on the Nodong and the second stage
based on the Shahab-1, which has a smaller 80 cm diameter, or on a lengthened
Scud. For the third stage, Iran could buy a little motor from somewhere. This
is the most reasonable and the quickest thing to do if Iran wants to put its
flag in space.
IW: So you think that the Shahab-3 will probably be the last single stage missile and that the next missile up the line in Iran will be a staged missile?
UR: I’m not saying that. I’m saying that an Iranian satellite launcher would be multi-stage. Whether Iran will exploit that capability to make a multi-stage ballistic missile, I don’t know. I would be very careful about saying that because it’s a political issue. A multi-stage missile would project power over Europe. If Iran wants to continue engaging Europe then I don’t think it makes sense to threaten Europe. I would say that Iran’s satellite launcher will be multi-stage and once it has that, Iran won’t have to make an ICBM. If the Iranians are smart, they’ll do it by implication. All they have to do is orbit satellites and make threats against America once in awhile. That will be enough to tell the United States that it could be hit by an Iranian ICBM.
IW: So you think that politically it makes more sense for Iran to do a space launcher and let people draw their own conclusions.
UR: Yes, this seems like the rational way of doing things. But let me qualify my answer. The election of Ahmadinejad may have changed things. Since his election there has been a shift in Iranian rhetoric. It has become more belligerent and more confrontational than ever before. Ahmadinejad may not be interested in engaging Europe. A guy who denies the Holocaust and is facing a lot of criticism from Europe because of such statements may be giving up the path of engagement.
IW: A concern raised about Iran’s space program is that it facilitates Iranian imports. Do you think it will be easier for Iran to import equipment and material useful in missiles under the guise of its space program?
UR: Well, Iran declared its space program in 1998. It didn’t attract a lot of attention at the time, but Iran is on record on this issue since 1998. And because of this program, Iran claims the right to import technologies that would allow it to go into space. However, from the perspective of the international community, the Missile Technology Control Regime (MTCR), which has about 40 member states, controls the sale of missile-related technologies. Under the MTCR, space launchers are considered missiles. So Iran shouldn’t get anything that can help it make space launchers. Even so, Iran is getting by without legally obtained technical assistance.
IW: Can you give us more details about what you think the North Koreans, the Chinese and the Russians are supplying to Iran now?
UR: You have to look very carefully at the statements the Chinese make about
controlling missile technology. China says it will abide by the ban on selling
complete missile systems. It issued a regulation in 2001 or 2002 that looked
very much like the MTCR, but that lacked a clause on the presumption to deny
the export of category I items. My feeling is that the Chinese permit themselves
to export a lot of materials and technologies that the MTCR forbids.
For what the North Koreans have supplied, you need only look at the Shahab-3. That is a North Korean missile, from the tip to the bottom. The Russians have supplied Iran with rocket motor technology.
IW: What kind of rocket motor technology have the Russians supplied? Can you be more specific?
UR: I would say older technology: room temperature liquid propellant, SS-N-4 technology. Iran has not gotten new technology, like storable liquid fuel propellant, which is a more energetic kind of fuel, with a different oxidizer. Russia is supplying older, Scud-age technology.
IW: Do you think that Russia provided Iran with SS-N-4 technology?
UR: There was a lot of undisclosed transfer of technology and know-how from Russia to Iran in the 1990s. The type of technology was not disclosed, but it was more than just motors.
IW: Do you think this activity is still going on between Iran and Russia?
UR: I assume that some of it may still go on. Open sources suggest that some experts went from Russia to Iran in order to make money. Some of these experts may still be in Iran, may even be Iranian citizens by now. Whether you call this Russian support or not, I don’t know. But there could be expatriate Russians in Iran right now helping them along. But I don’t think there is any official Russian government assistance to Iran. Even in the 1990s, it may not have been official Russian government assistance. Russia in the early 1990s was not a very organized state. There were lots of illegal activities inside Russia and a lot of illegal exports from Russia. And not only Russia. Remember Ukraine. There was recently the report about the KH-55 cruise missiles that went to Iran from Ukraine.
IW: Would you say that North Korea is Iran’s main missile supplier?
UR: Yes. But remember the story about the BM-25. This is a very complicated missile. It’s not that easy to replicate. You can’t copy it just by buying an old missile and taking it apart. You need hands-on experience in order to copy it. And if you want to extend the range, you need a lot of expertise that is not attainable just from looking at the missile. If North Korea built such a missile, there had to be some technology exchange with Russia. My feeling is that there is deep Russian involvement—not with Iran, but with North Korea. North Koreans have good grounding in missiles, and their experts probably all went to Russian universities. But the North Koreans still have a limited capability.
IW: What is the status of Iran’s space program? Is this the thing to watch in the future?
UR: Yes. As I said, the Iranians do not hide their space program. They are working on various satellites. The first is the Zoreh, a communications satellite, which was made by and will be launched by Russia. It is Iranian in name alone. A second satellite, the Sina-1, was made in Russia and launched in Russia in October 2005 by a Kosmos 3 rocket. Again, it’s Iranian by ownership and not by make. But it’s there, it belongs to Iran and Iran apparently built a ground station to control it. There are two other satellites, one of which is called Mesbah and is made by an Italian company. Iran claims that this is a joint venture and that it is also contributing. Finally, there is a small 20 kg satellite that Iran says will be orbited at an undisclosed date by an Iranian launcher.