Iran has an ambitious space program. But it also has an ambitious missile program as well. Iran is now developing a larger new rocket called the Simorgh, with the goal of placing a new satellite in orbit by February 2017. Many in the United States worry that the Simorgh might also serve as the basis for an ICBM.
Concerns about Iran’s space program arise from the fact that it is largely built on technologies imported from North Korea. The collaboration between Iran and North Korea in developing rockets for civilian space launches or military missions is a subject of frequent concern in the United States. And while that collaboration has largely been seen as North Korean assistance to Iran, there are now indications that the relationship has become more collaborative over time.  In some instances, the flow of technology could even be shifting in the other direction, with Iran supplying North Korea with assistance. This may force us to change how we think about addressing the threat from Iran and North Korea’s missile programs.
See the model below for a side-by-side comparison between Iran’s Simorgh and North Korea’s Kwangmyongsong space launch vehicles.
Click the play button to learn more about the Simorgh and Kwangmyongsong (Unha-series) space launch vehicles. Model credit: Nate Taylor (NPTS ’17).
The Simorgh has been a source of concern to the United States, whose intelligence community has stated that its “technology could be used for an ICBM-class vehicle.”  The Simorgh is built by Shahid Hemmat Industrial Group (SHIG), which the United States has sanctioned for its role in Iran’s liquid-fueled missiles program.
The Simorgh uses engines developed for the Shahab-3 medium-range ballistic missile (See annotation 1 in the Sketchfab model). The Shahab-3 is Iran’s version of North Korea’s Nodong missile, which Iran improved with assistance from Russian and Chinese entities. 
Iran’s liquid-fueled missile program is based on the engine that North Korea developed for its Nodong medium-range ballistic missile. Iran’s version of the Nodong engine is used in a missile called the Shahab-3.
Specifically, the first stage of the Simorgh uses a cluster of four Shahab-3 engines. This approach is very similar to North Korea’s Unha launch vehicles, whose first stages have used a cluster of four Nodong engines (Annotation 2). 
Both the Unha-series and the Simorgh utilize a cluster of four such engines in the rocket’s first stage. But there are differences in the configuration of the engines that suggest Iran has made the design its own.
Iran’s space program has generally followed the steps taken in North Korea. Iran’s Safir launch vehicle is similar in approach to North Korea’s Paektusan (TD-1) SLV, just as the Simorgh is similar in approach to North Korea’s Unha (TD-2) SLVs.
Iran’s development approach seems to be more incremental and cautious than North Korea’s. Iran tests its rockets before trying to launch satellites. The same outlook is expressed in less aggressive design choices: Safir and Simorgh have only two stages each, compared to the three stages of the TD-1 and TD-2.
The first stage of the Simorgh is significantly larger than the first stage of the Unha-series (Annotation 3). Estimates derived from models of the Simorgh displayed in public suggest it is about two meters longer, suggesting that it carries more propellant and possibly that the airframe is more advanced.
Although the total length of the three-stage Unha-series is taller, the first stage of the Simorgh is about a meter taller.
The ratio of the fuel and oxidizer tanks is different from the Unha, too, suggesting the Simorgh may use a different combination of propellants (Annotation 4). The ratio is suggestive of liquid oxygen as an oxidizer, although additional evidence would be needed to make a definitive judgement. If the fuel does turn out to be liquid oxygen, this would suggest the Simorgh is not likely to serve as the basis for an ICBM since liquid oxygen is generally considered difficult to handle.
Moreover, the ratio of the fuel and oxidizer tanks is different, suggesting a different combination of propellants.
North Korea’s Unha-series may now incorporate some Iranian technologies. North Korea’s Unha-2 launch in 2009 failed when the rocket’s third stage did not separate properly. North Korea’s first successful Unha-series launch, in December 2012, used a larger third stage that appeared to be similar to a rocket stage previously seen only in Iran. Iranian designers created the stage using vernier engines similar in design to those found in a Soviet-era submarine launch ballistic missile that North Korea sold to Iran in the mid-2000s. (Annotation 5).
In addition to apparent improvements in the Simorgh, the Unha-series may now incorporate some Iranian technologies. The third stage of the Unha appears similar to a rocket stage first seen in Iran on the Safir SLV.
Iran reportedly conducted the first Simorgh test-launch on April 19, 2016. A second test is scheduled for the autumn of 2016. Iran plans to use a Simorgh to launch a satellite, possibly the Tolou (Sunrise) remote-sensing satellite, into orbit to mark Victory Day in February 2017 (Annotation 6) .
Iran plans to use a Simorgh to launch a satellite, probably the Tolou (Sunrise) remote-sensing satellite, into orbit to mark Victory Day in February 2017.
Will the Simorgh’s elongated first stage eventually appear in North Korea? North Korea is developing larger launch vehicles. Notably, it has already increased the height of its launch gantry at the Sohae Satellite Launch Center. 
Recent evidence suggests a more collaborative approach on launcher technology, rather than a one-way street. The U.S. Treasury recently sanctioned a number of individuals associated with SHIG and Iran’s Ministry of Defense and Armed Forces Logistics (MODAFL), noting that “Iranian missile technicians from SHIG traveled to North Korea to work on an 80-ton rocket booster being developed by the North Korean government.”  Two individuals were identified as “critical to the development of the 80-ton rocket booster.” The new booster engine, which further underscores North Korea’s commitment to bigger rockets, has yet to appear in either country, and may yet be years away.
In the meantime, if recognizable aspects of the Simorgh were to appear in North Korea’s space launch programs, it would shift how analysts understand the relationship between North Korea and Iran. It would also invite a fresh look at whether Iran is becoming an important supplier of missile technology to developing countries, much as North Korea has been in the past. US intelligence estimates state that Iran “has marketed at least one ballistic missiles system for export.”  Iran’s isolation from the international community has lessened with the successful implementation of the Joint Comprehensive Plan of Action to address concerns about Iran’s nuclear program, while North Korea’s isolation has deepened. But sanctions on North Korea are likely to be less effective if Tehran becomes a key supplier to Pyongyang’s missile programs.
The nonproliferation community should be alert for indications that the flow of liquid-fueled rocket technology between the two partners has begun to reverse direction. Improving relations with either Iran or North Korea will require addressing the missile programs that both countries are developing. Historically, these were treated as separate issues, without North Korea being seen as the source of the problem. But that view may now be outmoded. It may be possible to address the missile threats posed by either Iran or North Korea, but this may require addressing those threats together, not separately.
 Geoff Forden, "Secret Iranian Missile Memos," Arms Control Wonk, September 14 2009, www.armscontrolwonk.com.
 James R. Clapper, "Statement for the Record on the Worldwide Threat Assessment of the U.S. Intelligence Community for the House Permanent Slect Committee on Intelligence," Office of the Director of National Intelligence, February 10 2011, intelligence.house.gov.; See Also Robert Wood, "Iranian Launch of Satellite", U.S. Department of State - Bureau of Public Affairs, February 3 2009, www.state.gov
 Melissa Hanham, Jeffrey Lewis, David Schmerler, "3D View: North Korean and Iranian Missile Collaboration?," Nuclear Threat Initiative, March 18 2015, www.nti.org.
 We use Unha-series to refer to the series of two stage rockets described in the United States as the Taepodong-2 and launched between 2006-2016. The exteriors of these rockets have displayed different markings including Chosun/조선 (Korea), Unha-3/은하-3 (Galaxy-3), and Kwangmyongsong/광명성 (Shining Star).
"“پرتاب آزمایشی ماهوارهبر سیمرغ در اوایل سال ۹۵/ "سیمرغ" بهمن سال آینده با ماهواره به فضا میرود”," (Simorgh satellite carrier test launch earlier in the year 95 / "Phoenix" is February next year satellite into space), Tasnim News, March 15 2016, www.tasnimnews.com/. and Ali Javid, "Iran Manouchehr Manteghi: Simorgh IRILV & Imam Khomeini space center & Tolu satellite منوچهر منطقی", YouTube, February 2 2016, www.youtube.com. Thanks for Roxana Vazirpour Kennedy (NPTS ‘17) for translation.
 For a video tour of the Sohae facility, see: www.nti.org/learn/facilities/202/
 "Treasury Sanctions Those Involved in Ballistic Missile Procurement for Iran", U.S. Department of the Treasury, January 17 2016, www.treasury.gov.
 "Unclassified Report to Congress on the Acquisition of Technology Relating to Weapons of Mass Destruction and Advanced Conventional Munitions, Covering 1 January to 21 December 2011", Office of the Director of National Intelligence, 2011, fas.org.