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Posts Tagged ‘Iran’

Pentagon Changes Its Assessment of Iran’s ICBM Prospects

Inside Defense reports that the Pentagon’s assessment of the Iranian intercontinental ballistic missile (ICBM) threat has changed substantially for the first time since 1999. The new assessment appears in the unclassified executive summary of the Pentagon’s January 2014 Annual Report on Military Power of Iran. Read More

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Iran Space Launch Program: Update

While the world is focusing on negotiations over the Iranian nuclear program, where do things stand on the other piece of the puzzle, the Iranian space-launch and missile program? Read More

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Timeline for an Iranian ICBM: Differing Assessments?

Last week, the Pentagon released an unclassified summary of its  Annual Report on Military Power of Iran, dated January 13.  Inside Defense wrote a story on it, “DOD: Iran, With Foreign Help, Could Demonstrate ICBM By 2015. The story focuses on the report’s conclusion that

With sufficient foreign assistance, Iran may be technically capable of flight-testing an intercontinental ballistic missile capable of reaching the United States by 2015.

This conclusion is only slightly modified from the April 2012 Report, a year ago, which concluded

With sufficient foreign assistance, Iran may be technically capable of flight-testing an intercontinental ballistic missile by 2015.

This change seems intended to clarify its assessment since technically the term “intercontinental ballistic missile” means one with a range of more than 5,500 km, while Iran would need a missile with range of over 10,000 km to reach population centers in the U.S.

The article made something of the apparent contradiction of the DOD report with a December 2012 assessment of Iran’s ballistic missile program by Steven Hildreth for the Congressional Research Service. Hildreth writes:

It is increasingly uncertain whether Iran will be able to achieve an ICBM capability by 2015 for several reasons. Iran does not appear to be receiving the degree of foreign support many believe would be necessary, Iran has found it increasingly difficult to acquire certain critical components and materials because of sanctions, and Iran has not demonstrated the kind of flight-test program many view as necessary to produce an ICBM.

Similarly, last July Michael Elleman at IISS speculated on the slow pace of ballistic missile development:

There is mounting evidence to suggest that, whereas the sanctions regime has not prevented Tehran from operating an increased number of centrifuges for uranium-enrichment activities or adding to its stockpile of fissile material, it has stymied efforts to develop and produce the long-range ballistic missiles capable of striking potential targets in western Europe and beyond.

Is this really a contradiction?  While the Pentagon’s approach to assessing  Iran’s ballistic missile program has changed over the years, the above Pentagon reports  estimate the shortest timeline for Iran to acquire an ICBM capability, under the best conditions—in this case, with “sufficient foreign assistance.” What that assistance might consist of is not provided in the unclassified summaries.  The CRS and IISS reports instead talk in specifics about what kind of foreign support Iran might actually be getting and how that might realistically affect its timeline.

To those accustomed to thinking in math terms, the Pentagon appears to be giving the “lower bound” of when Iran might achieve ICBM capability, not assessing the most likely value. That’s one useful piece of information, but not the whole picture.

 

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Markus Schiller’s Analysis of North Korea’s Unha-3 Launcher

North Korea’s launches of its Unha-3 rocket in April and December 2012, along with the recovery and analysis of debris from the December launch, have provided a lot of new information that was not previously available. That information has allowed me and others to reassess our earlier conclusions about Pyongyang’s rocket, and has led to some significant changes. Read More

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Timeline for an Iranian Solid-fuel ICBM?

In assessing the ballistic missile threat, a key issue is estimating how long it might take countries like North Korea and Iran to build missiles that could carry a nuclear-warhead-sized payload to the United States. Both countries use liquid fuel in their satellite launchers and have developed that technology further than solid fuel. As a result both countries could develop a liquid intercontinental ballistic missile (ICBM) before a solid ICBM. Read More

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Iran’s Launch Today–and in the Future

Iran’s English Language outlet Press TV reports today that today (Monday) Iran has successfully launched a monkey on a suborbital flight in its new capsule called Pishgam (Pioneer). The Iranian Fars news agency said the capsule was lofted to the desired altitude of 120 km, sent back telemetry, and returned to earth where the monkey was retrieved safelyRead More

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South Korea’s Analysis of North Korea’s Rocket Debris

South Korea recently released a short summary (in Korean) of its analysis of the pieces it recovered of North Korea’s first stage from its Dec. 11 satellite launch. Parts of the analysis have been showing up in the South Korean press in the last few days.

Here is a translation that I did of that summary (with the help of Google and a student who wants to remain anonymous). Corrections from readers are welcomed. Read More

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Iran Exaggerates Missile Accuracy

Iran announced today that it had successfully test launched a new version of its short-range Fateh 110 missile, claiming it has an upgraded guidance system that gives it high enough accuracy to “hit and destroy both land and sea targets, enemy concentration points, command centers, missile sites, ammunition dumps, radars and other targets with 100 percent precision.”

This claim is not credible, for the following reason.The Fateh 110 is reported to be a domestically built ballistic missile with a range of 300 km and a 250 kg warhead. Note that a warhead of this mass is too light to be a nuclear weapon.

A ballistic missile is only guided during the first minute or so of flight when its engines are burning. During that time, the guidance system attempts to steer the missile to put in on the right trajectory to hit the intended target. Once the engine burns out, the missile flies without power and cannot be steered. This is like throwing a ball: you aim the ball by the speed and direction your arm gives it, but once the ball leaves your hand it flies on its own. (The fact that missiles fly unpowered for most of their flight is why ballistic missiles are called “ballistic.”)

Once they are launched, ballistic missiles have two main sources of inaccuracy.

  1. The guidance system steers the missile while the missile’s engines are burning. One source of inaccuracy is the inability of the guidance system to put the missile on exactly the right trajectory to hit the target. These errors in accuracy are called “guidance and control errors.”
  2. A missile of this range will reach a maximum altitude of about 75 km, which is above the bulk of the atmosphere. When the missile reenters through the atmosphere toward the ground at high speed, it is subjected to a number of forces that can knock it off its intended trajectory. It is buffeted by high altitude winds and density variations in the atmosphere. In addition, atmospheric forces due to asymmetries in the missile body or warhead or a spiraling of the missile as it reenters also affect its reentry. These are called “reentry errors.”

Even if Iran had developed a perfect guidance system so there were no errors of type (1), there would still be very significant reentry errors, which are not reduced by a better guidance system. The reentry errors could be many hundreds of meters.

As a result, the idea that this missile has an accuracy high enough to allow it strike relatively small targets like ships, command centers, or radar bases, is simply not credible.

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Iran’s Upcoming Launch: Fajr Satellite

Iran has announced its plan to launch the Fajr (Dawn) satellite as early as next Wednesday, May 23. The Fajr, as you may recall, was meant to be launched in October 2011, and then by the end of the last Iranian year (which ended this past March 19). But the plan was postponed due to “some pilot tests,” according to Hamid Fazeli, the head of Iran Space Agency (ISA).

Fazeli also said that the Fajr satellite represents a “remarkable breakthrough” for Iran’s space technology, marking the transition of Iran’s satellite technology from research orbiters to practical and operational satellites.

This is an interesting comment and is presumably related to the ability of Fajr to maneuver on orbit—something new for Iranian satellites.To maneuver, the satellite will use a cold gas thruster—a simple but reliable system not unlike releasing air from a balloon.

This maneuver will boost the lifetime for the satellite. Iran’s previous satellites were able to stay in orbit only a few months before the atmosphere’s drag pulled them out of orbit, but Iran has said Fajr will orbit for a year and a half. Reports conflict about the initial and final orbits. Some say the satellite will move from an initial 250 km circular orbit to a final elliptical orbit with apogee at 400 or 450 km, while others say the final orbit will be a circular orbit at these higher altitudes.  As we mentioned in an earlier post, such a maneuver should only take a few kg of fuel.

Based on lifetime, it appears the aim is a circular orbit at the higher altitude. According to Wang Ting, the lifetime of the Fajr in a 450 km circular orbit could be more than 460 days; in an elliptical orbit with its perigee at 250 km and apogee at 450 km the Fajr would come down after about 50 days, around the same lifetime as the Omid and Rasad (a few months), and longer than Navid (a few weeks).

Fajr is reportedly equipped with a domestically made GPS navigation system to help Iran keep track of its orbit. The satellite is intended to transmit pictures of the earth with a resolution of 500-1000 meters. (Recall that the resolution of Google Earth images for most of the earth is about 15 meters and for images of the United States is about 1 meter or better.)

The Fajr satellite will be launched with a Safir 1B launcher, as was the Navid satellite this past February. The Safir launcher is essentially a Shahab-3 missile (which is very similar to the North Korean Nodong missile) as the first stage with a small second stage on top. It is much smaller than the Unha rocket North Korea recently unsuccessfully launched, with a mass of less than 30 tons compared to about 85 tons for Unha. It can only lift lightweight satellites to relatively low altitudes.


                                     Figure adapted from this report.

Iran has a few more satellites in queue that can be launched this way, such as the recently announced Sharif and Nahid. (Different versions of this information appear, apparently from imperfect translation, so reader’s comments on the Persian language reporting would be appreciated.)

Iran also announced that it would send more living creatures into space in the next two or three months. Reports vary but point to the launch of the Tolou (Sunrise) and Zafar or Mesbah satellites by the end of the year. The Mesbah apparently refers to a home-grown version of the original Mesbah satellite; the original satellite was manufactured almost a decade ago for Iran by Italy, which failed to deliver the satellite to Russia for launch and which has not returned it to Iran either, presumably following the spirit of UN sanctions.

Because of their larger mass and higher planned orbits, the Tolou and Zafar satellites await the larger Simorgh launcher, which is being developed. The Simorgh appears to be closer in size and capability to the Unha, using in its first stage a cluster of 4 of the Safir first-stage engines. The original Mesbah satellite was 75 kg, so would need to go on the Simorgh as well if the new one is similar to the old one.

Farahi also said that Iran plans in its next Five-Year Development Plan to develop a satellite launcher that can launch a 1 ton satellite in a 1,000 km orbit. This would be well beyond the capability of the Unha or likely the Simorgh.

While discussion of this proposed launcher appears often in the press paired with the suggestion that a launcher capable of putting a satellite in GEO is imminent, getting to GEO requires considerably more capability.

More on Iranian launchers in a future blog post.

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Another Iranian Satellite Launch: Navid

Iran successfully launched its third satellite into orbit on Friday, Feb. 3 at 3:34 am local time in Iran (7:04 pm Feb. 2 EST), 2 years and a day after placing its first satellite, Omid, into space.

The satellite was the 50 kg Navid which was reportedly built by students at the Sharif University of Technology. Iranian reports say this was the first satellite “completely designed and built by Iranian experts,” which raises questions about the design and manufacture of the two previous satellites.U.S. tracking shows Navid was in an initial orbit with a perigee of 275 km, an apogee of 374 km, and an inclination of 56.0 degrees. This is close to the intended orbit announced early last year (250 km x 375 km at 55 degrees), which suggests that Iran has fairly good control of the launch trajectory.

The satellite is expected to stay in orbit for several months. It is roughly cubical, about half a meter on a side. Reports say it will take panchromatic black and white images with a resolution of around 400 meters that it will transmit to Earth, and that it will collect data on weather conditions and monitor natural disasters.

This website shows the orbit and current location of Navid.

Officials said that the satellite is controlled by 5 ground stations spread around Iran, which are shown on the map below.

The Iranian Space Agency said the satellite was launched using the Safir 1-B rocket. The Safir is a 2-stage liquid-fueled launcher with a mass of about 26 tons. The first stage is essentially a Ghadr-1 missile, which uses a single Nodong engine. (The Ghadr-1 is a Shahab-3 missile with additional propellant and a lighter body.) The Safir second stage uses small engines similar to those of the Soviet SSN-6 missile.

Iranian press reports said the Safir 1-B is a modification of the launcher used for its previous satellites but with “20 percent more launch power.” However, this claim is doubtful since the orbits of Navid and Omid (246 km x 381 km x 55.7deg) require essentially the same speed to insert them into their orbits (7.79 km/s for Navid vs. 7.81 km/s for Omid), and the increase in payload mass from 27 kg (Omid) to 50 kg (Navid) is a tiny fraction of the overall launcher mass. The higher altitude for orbit insertion of Navid compared to Omid (275 km vs. 246 km) requires only a few percent increase in “launch power,” which could be accomplished, for example, by increasing the thrust slightly or reducing the body mass of the launcher.

Earlier reports suggested that the Navid would be launched on the Simorgh launcher that Iran is developing, but this launcher has not been flight tested. It would be a much larger rocket than Safir, similar to a two-stage version of North Korea’s Unha-2 launcher, with a mass of roughly 80 tons. That launcher would use a cluster of 4 Nodong engines for the first stage; in 2010, Iran displayed what appears to be this cluster of engines.

Current speculation is that Iran is planning to launch the Toulou and Zafar satellites next, but these are intended to go in higher orbits and will need to wait for a more powerful launcher than Safir.

The Fajr satellite, which announcements last year said would be launched in October 2011, has so far not been launched, for unknown reasons.

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