Prelude to an ICBM? Putting North Korea’s Unha-3 Launch Into Context
Last December, after two decades of development and four failed attempts since 1998, North Korea finally boosted a small satellite into orbit using a domestically assembled Unha-3 rocket. Although the Kwangmyongsong-3 satellite failed to orient itself properly and never beamed signals to earth-based stations as designed, Pyongyang nonetheless heralded the launch as an epic national achievement.
The December launch, like those that preceded it, was promptly denounced by the international community. On January 22, after a month of intense negotiation, the UN Security Council passed Resolution 2087, which condemned North Korea’s use of ballistic missile technology in violation of Resolutions 1718 and 1874. On February 12, in the wake of UN efforts to denounce the satellite launch, North Korea tested a nuclear weapon.
Although international anger over Pyongyang’s launch using the Unha-3 rocket is understandable, efforts to condemn and punish North Korea for it might not be properly placed. Policymakers around the world face an important choice. They can impose further demands on an already heavily sanctioned country for exploring outer space, albeit using missile technologies. Alternatively, they can scale back their collective reaction to North Korean provocations that do not pose an immediate or significant threat and instead preserve their punitive responses for those activities that are most threatening, such as the February 12 nuclear test or future flight tests of long-range ballistic missiles. The history of ballistic missile development in other countries, which shows that space launches do not and cannot play a decisive role in the creation of long-range missiles, suggests the latter.
In a 1993 speech to the Central Committee of the Workers’ Party of Korea, Kim Il Sung, North Korea’s leader from his founding of the country in 1948 until his death in 1994, called for North Korea to join the exclusive list of space-faring nations. Pyongyang’s formal decision to begin developing a space launcher and earth-orbiting satellites likely followed that speech.
The February 1994 discovery by U.S. spy satellites of two rocket bodies at the Sanum-dong research and development center on the outskirts of Pyongyang and reports of ground-based engine tests related to a large rocket using a Taepo Dong rocket test stand suggest that informal activities aimed at fashioning a satellite launch vehicle or long-range ballistic missile began well before Kim’s 1993 speech.
The existence of the rockets spotted in U.S. satellite imagery suggested that North Korea was concurrently pursuing two large-rocket development projects. The first system, named Paektusan-1 by North Korea and dubbed Taepo Dong-1 by U.S. intelligence agencies after the name of a village near the Musudan-ri launch facility on North Korea’s east coast, was thought to be a two-stage rocket based on the Nodong and Hwasong-6 (Scud-C) missiles. Most probably, the rocket was designed to help North Korea master the process of staging, a key technology for creating long-range missiles and satellite launchers. A second, more ambitious program featured the much larger Paektusan-2 (Taepo Dong-2), which was believed to have a first stage consisting of a cluster of four Nodong engines and a modified Nodong missile as the second stage.
Four years after initially sighting the Taepo Dong rockets, U.S. intelligence detected activities consistent with preparations for a missile test or satellite launch at the Musudan-ri facility. Despite diplomatic efforts by Washington and others to dissuade Pyongyang from testing a missile, North Korea launched the rocket on August 31, 1998. To the surprise of many, the Taepo Dong-1 was not a two-stage ballistic missile as previously thought, but rather a three-stage rocket configured to place the small Kwangmyongsong-1 satellite into orbit. The first two stages appear to have performed as designed, and the third stage is believed to have separated from the second, but malfunctioned soon thereafter, with the remains of the third stage and the satellite plunging into the ocean roughly 1,600 kilometers from the launch site.
Although the vehicle’s trajectory was consistent with an attempted space launch, its flight path crossed Japanese territory. In the diplomatic uproar following the launch and under international pressure, Pyongyang entered into negotiations with Washington, resulting in the September 1999 flight-test moratorium agreement. Under the deal, North Korea promised to suspend future long-range missile tests, understood to include the Nodong and longer-range systems, while Washington agreed to lift a number of economic sanctions. Pyongyang adhered to the moratorium until 2006.
Taepo Dong-2 and Unha-2
The maiden flight of the Taepo Dong-2 occurred on July 5, 2006, roughly one month after the executive board of the Korean Peninsula Energy Development Organization decided to terminate its light-water nuclear power reactor construction project, which was created as part of the 1994 Agreed Framework between Washington and Pyongyang. The Taepo Dong-2 launch was accompanied by the firing of six additional missiles, all taking place within a 14-hour window. The near-simultaneous launch of seven missiles suggests that the exercise was not designed to meet a technical imperative or to orbit a satellite. It is more likely that Pyongyang sought to convey a political message by launching a salvo of missiles.
Regardless of the reasons behind the test, the Taepo Dong-2 exploded roughly 42 seconds into its flight, well before analysts could determine whether they were observing a ballistic missile test or a satellite launch. Because Pyongyang never released a technical description or photographs, the rocket’s configuration remains a public mystery.
On February 24, 2009, the Korean Committee for Space Technology declared that it was preparing to launch an Unha-2 rocket for the purpose of orbiting a Kwangmyongsong-2 experimental communications satellite. Taking lessons from the diplomatic fallout from the earlier launches in 1998 and 2006 and making an obvious attempt to minimize potential criticism and sanction, Pyongyang announced in March 2009 that it intended to adhere to the Outer Space Treaty and the Convention on Registration of Objects Launched Into Outer Space. It notified the International Civil Aviation Organization and the International Maritime Organization that it planned to launch the satellite during April 4-8. The notifications provided official warning to aircraft and ships to avoid the “hazard zones,” two large swaths of designated airspace and ocean where remnants of the rocket’s first and second stages were expected to fall.
After weeks of North Korean preparations and repeated international appeals to cancel the test, Pyongyang launched the Unha-2 on April 5, 2009. Breaking with the pattern of its previous missile tests or satellite launches, the North Korean government released a video recording of the Unha-2 firing, revealing for the first time information about the system’s configuration and its approximate performance characteristics. Nevertheless, it remains unclear if the Unha-2 is a replica of the 2006 Taepo Dong-2 or a new system altogether.
Flight data gathered by the Japanese Ministry of Defense and published in the Japanese press indicated that the first two stages of the Unha-2 performed as North Korean engineers had projected. The first stage splashed down in the East Sea approximately 540 kilometers from the launch site, within the hazard zone designated by North Korean officials before the flight, albeit at the edge of the zone closest to the Korean coastline. The second stage landed in the Pacific Ocean, roughly 3,200 kilometers from Musudan-ri, within the hazard zone, but at the forward edge. It is unclear if the third stage separated from the second stage. If it did successfully separate, it might not have ignited properly. The third stage and satellite tumbled out of control and fell into the ocean very near the second-stage impact location.
Shortly after announcing the “Leap Day deal,” the February 29, 2012, agreement under which the United States agreed to provide food assistance in exchange for a North Korean moratorium on “long-range missile launches,” uranium enrichment, and nuclear testing, Pyongyang declared that it would again attempt to loft a satellite into orbit using an Unha rocket. The launch was slated to coincide with Kim’s 100th birthday.
Although there was no doubt that the planned launch would violate the terms of the newly minted agreement, as well as Resolutions 1718 and 1874, officials in Pyongyang clumsily attempted to minimize the diplomatic fallout by declaring beforehand that the launch was to be part of a peaceful space program. North Korea notified international organizations responsible for maritime and airspace safety of the anticipated launch dates and the expected hazard zones, where launch debris were expected to hit the ocean. Additionally, Pyongyang invited foreign observers to the new Sohae launch facility, situated near the western coastal city of Tongchang-ri, to witness the final preparations of the Unha-3 rocket and view a model of the Kwangmyongsong-3 satellite.
The Unha-3 was launched on April 12, 2012, but not in the presence of the foreign observers. As the rocket headed south from the launch site, as expected, it reportedly failed after approximately 100 seconds of flight. Sections of the rocket and satellite were strewn across a swath of sea west of South Korea. The timing of the failure and the impact locations of the debris indicate that a malfunction occurred during first-stage operation, but the precise cause cannot be determined from available data. Pyongyang did not release any video of the launch.
Prelaunch photographs of the Unha-3 show it to be a near copy of the Unha-2 fired in 2009 although the third stage appears to have been stretched by 30 to 50 centimeters, presumably to carry additional propellant. High-resolution photographs indicate that the second stage was neither a modified R-27—a retired Soviet submarine-launched missile, known in the West as the SS-N-6—nor a stage that employs the higher-energy propellants associated with the R-27, as some analysts had concluded after the 2009 launch. Indeed, the relative size of the oxidizer and fuel tanks found on the second stage is consistent with the propellant combination used by the Nodong engine.
Last November, North Korea announced a second attempt to boost the Kwangmyongsong-3 satellite into orbit using the Unha-3. The launch presumably was timed to coincide with the first anniversary of the death of Kim Il Sung’s son and successor, Kim Jong Il, and the ascension to power of the latter’s son, Kim Jong Un. The timing of the launch, so soon after the unsuccessful attempt in April, suggests that North Korean engineers were able to identify and correct the technical fault that doomed the first Unha-3 firing. Yet, it is possible that political imperatives trumped technical ones and that the Unha-3 was fired before engineers could make the appropriate adjustments.
Assembly, systems checks, and fueling of the Unha-3 at the Sohae facility lasted about two weeks. Inclement weather and a minor technical glitch may have delayed the launch by a few days, but on December 12, the Unha-3 lifted off and successfully inserted a satellite into a sun-synchronous orbit, which required the third stage to execute a challenging dogleg turn to avoid overflying populated territory. The satellite, once in orbit, failed to stabilize its orientation relative to the earth’s surface, precluding it from capturing images as planned. The satellite also failed to transmit signals to receiving stations on earth.
Missile Test or Satellite Launch?
Pyongyang has repeatedly insisted that the sole purpose of the Unha-3 launch was placing an earth observation satellite into orbit. The rocket’s trajectory and placement of a satellite in orbit support North Korea’s official claims, as does Pyongyang’s prelaunch notification to international organizations responsible for airspace and maritime safety. Further, the Taepo Dong-1 launched in 1998 was on a trajectory consistent with a satellite launch, as were the 2009 Unha-2 and the April 2012 Unha-3 firings. The 2006 launch attempt also might have been designed to orbit a satellite, but because it failed so early in its flight, it is not possible to determine the mission’s purpose.
Yet, international skepticism and criticism of North Korea’s intentions have prevailed. Susan Rice, the U.S. ambassador to the United Nations, in referencing the December launch, asserted that North Korea had fired “a multi-stage rocket using ballistic missile technology.” To be sure, the technologies and components employed by space launchers and long-range ballistic missiles are very similar, if not the same. Both use powerful rocket engines, high-strength and lightweight airframes, inertial navigation and guidance units, and payload separation mechanisms. Key features, however, differentiate the two systems, apart from the payload itself.
First, ballistic missile payloads must survive the rigors of re-entry into the atmosphere. Protecting a long-range missile’s payload from the extreme heat and structural loads experienced during re-entry requires the development and production of special materials, which must be tested and validated under real conditions.
A second, less obvious difference lies with the operational requirements. Before their flight, space launchers, unlike their ballistic missile counterparts, are prepared over a period of many days, if not weeks. Components and subsystems can be checked and verified prior to launch, and the mission commander can wait for ideal weather before initiating the countdown. If an anomaly emerges during the countdown, engineers can delay the launch, identify and fix the problem, and restart the process. In contrast, ballistic missiles, like all other military systems, must perform reliably under a variety of operational conditions, with little or no warning. These operational requirements impose a more rigorous validation scheme, which includes an extensive test program. Only after successfully completing validation testing is a missile deemed to be combat ready.
Although space launch activities offer an opportunity to accumulate experience and generate data that could aid efforts to develop long-range ballistic missiles, the results have limited application to ballistic missiles. Only a fraction of the overall missile development issues can be addressed when testing the system as a satellite launcher. Other requirements, most notably re-entry technologies and operational flexibility requirements, cannot be adequately addressed by satellite launches. A proven satellite launch vehicle would still need to be flight-tested as a ballistic missile a half-dozen or more times before it would be combat ready. For these reasons and others, the universal trend has been to convert ballistic missiles into space launchers, not the opposite, as evidenced by the Soviet, U.S., and Chinese experiences.
The Soviets, for instance, began development of the R-7 (Semyorka, or SS-6) intercontinental missile in 1954 and initiated flight trials in May 1957. Two dozen R-7s were tested as ballistic missiles before the weapon became operational. During the R-7 flight trials, a handful of prototypes were diverted from the military program and transformed into satellite launchers or lunar probes. The reconfigured and renamed launcher, dubbed Soyuz, boosted the first earth-orbiting satellite, Sputnik, on October 4, 1957.
The R-7 was an impractical ballistic missile. It was deployed in limited numbers, no more than six, and was soon replaced by the R-16 (SS-7), R-36 (SS-9), and UR-100 (SS-11) missiles, which offered greater deployment flexibility. The R-7, however, provided the foundation for the world’s most diverse and widely used family of satellite launchers. Derivatives of the R-7 have flown more than 1,800 manned and unmanned space missions since 1957.
The U.S. experience was similar but broader. During the latter half of the 1950s, the United States ambitiously pursued a handful of ballistic missile development efforts, each of which would also establish the foundation for satellite launch vehicles. The short-range Redstone missile, itself derived from the German V-2, was the basis for the Jupiter-A and -C experimental rockets and space launchers, as well as the Jupiter intermediate-range ballistic missile. The Jupiter-C, also known as Juno-1, placed the first U.S. satellite, Explorer-1, into orbit on January 31, 1958. The first U.S. manned missions to space were powered by Redstone rockets.
The Thor intermediate-range missile, propelled by a modified Jupiter engine, was eventually used as a satellite launcher and is the progenitor of today’s Delta family of heavy-lift systems. Similarly, the Atlas and Titan ballistic missiles were transformed into satellite launchers, providing the building blocks for a family of launch vehicles operated under the same names. Interestingly, the four-stage Vanguard rocket, designed specifically for launching satellites, was never used as a ballistic missile. It did, however, place the world’s fourth satellite into orbit on March 17, 1958.
Thus, space launch activities apparently played only a minor role, if any, in the development of U.S. and Soviet long-range ballistic missiles. In China, however, satellite launches might have significantly aided the military’s missile development efforts. The DF-3 and DF-4 intermediate-range missiles, as well as the CZ-1 satellite launcher, for instance, shared the same first-stage booster. Development of the single-stage DF-3 began in the early 1960s. It was first flight-tested in December 1966 and deployed in 1971. The two-stage DF-4 was flight-tested three times from December 1969 to November 1970. During this period, the CZ-1 satellite launcher, which was derived from the DF-4, was launched three times; and on April 24, 1970, it successfully lofted China’s first satellite into orbit.
Before the DF-4 was inducted into military service, however, it had to undergo two batches of additional flight trials. The first stretched from May 1976 to November 1977, and the second took place in 1980. The missile achieved combat readiness in late 1980, 10 years after China’s first successful satellite launch.
Similarly, China’s first intercontinental ballistic missile (ICBM), the DF-5, and its workhorse satellite launcher, the CZ-2, appear to have been developed in tandem. The first flight of the DF-5 came in late 1971; the second flight was in 1973. The missile was not launched again until June 1979, when it underwent operational flight trials before being deployed in August 1981. However, the CZ-2, which employed DF-5 booster rockets not used during the initial flight trials in the early 1970s, was launched four times during the six years spanning the second and third DF-5 test firings. It seems reasonable to conclude that technical issues related to the stalled DF-5 development effort were at least partially addressed by the CZ-2 space missions.
History strongly suggests that satellite launch activities have assisted long-range missile development to varying degrees, but civilian space efforts have never played a decisive role in the creation of a long-range missile. In each of the cases reviewed above, regardless of the number of satellite launches conducted during new missile development, extensive flight trials in the military mode were needed to confirm combat readiness. The same principles apply to North Korea. Unha launches, although troubling and politically provocative, are not a substitute for ballistic missile testing.
A Viable Weapon?
The Unha-3 consists of three stages. The first is powered by a cluster of four Nodong engines and steered using four small vernier engines. The available evidence suggests that the second stage is a modified Nodong missile, with a larger-diameter fuselage to accommodate additional propellant. The configuration of the third stage is not known with certainty, but is most likely similar to that of the second stage of Iran’s Safir launch vehicle, which is suitable for satellite launches but not powerful enough to propel a moderately sized military payload. If North Korea built a ballistic missile using the first two stages of an Unha-3, the notional missile might achieve a maximum range of 5,000 to 6,000 kilometers. To reach the continental United States, a powerful third stage would have to be developed and added to the first two stages of the Unha-3.
The Soviet Union considered an analogous upgrade in 1957, when Soviet designers suggested combining the main boosters of the R-12 and R-14 missiles to create the R-16 ICBM. The R-16 was successfully developed, but only after substantial redesign, including the development of new engines using more-powerful propellants. This Soviet experience suggests that North Korea would find it difficult to build an operational ICBM founded on the Unha-3 technology.
Nevertheless, North Korea could contemplate using the Unha-3 as the basis for an ICBM. The missile would weigh more than 90 tons, making it too large and cumbersome to be viably deployed on a mobile launch platform. Silo deployment might be possible, but North Korea is a relatively small country and would find it difficult to conceal the location of its silos. Further, all of North Korea’s silos would be fewer than 200 kilometers from the coastline and thus vulnerable to pre-emptive strikes by advanced military powers, such as the United States.
A new missile design seems more likely. In April 2012, North Korea unveiled mock-ups of a mobile, long-range missile during a military parade in Pyongyang. The missile has never been tested, and its origins are not known. If propellants more energetic than those used by the Unha-3, Nodong, or Scud missiles were employed, the new missile might be capable of intercontinental range. Until it is flight-tested, however, such possibilities remain speculative.
North Korea and Iran
Satellite launch activities provide Pyongyang with a platform for exploring and demonstrating new technologies relevant to the creation of an ICBM. The international community should discourage such activities through diplomatic and other means. Satellite launches, however, are not a substitute for ballistic missile flight trials. North Korea cannot develop an operationally sound ICBM without first conducting a series of test flights in the ballistic missile mode.
The international community therefore should refrain from overreacting to North Korean satellite launches. Condemnations of space-related activities that utilize ballistic missile technologies are warranted and necessary. However, the threat of coercive measures such as economic and trade sanctions or enforced embargoes should be reserved for dissuading North Korea from testing nuclear weapons and long-range missiles. If such tests occur, punitive measures should be available to punish North Korea for its actions. North Korea’s recent nuclear test in the wake of the December Unha launch and subsequent UN Security Council resolution are a case in point. Diplomatic initiatives and the threat of punitive action during the first months of 2013 should have focused on deterring Pyongyang from testing a nuclear weapon rather than punishing North Korea for having used the Unha-3 to loft a satellite into orbit.
The same rule of thumb should apply to Iran. Tehran has stated that it will boost a satellite into orbit using a Simorgh launcher later this year. The Simorgh, if it resembles the launch vehicle mock-up unveiled by Iran in February 2010, will be a large rocket, comparable to the Unha-3. Although such a rocket could establish the basis for an intermediate-range ballistic missile capable of threatening all of Europe, it would not be a decisive step toward that goal.
Iran would necessarily have to modify the Simorgh, develop re-entry technologies, and repeatedly flight-test the new system as a ballistic missile, all of which take time. Reaction to a Simorgh satellite launch should be measured and consistent with the long-term threat it poses, but should not complicate efforts to induce a peaceful resolution to the Iranian nuclear standoff.
Michael Elleman is senior fellow for regional security cooperation at the International Institute for Strategic Studies and is principal author of “Iran’s Ballistic Missile Capabilities: A Net Assessment” (2010). He spent 20 years developing ballistic missiles at Lockheed Martin Corp. before joining the UN Monitoring, Verification and Inspection Commission as a missile expert for weapons inspection missions in Iraq. From 1995 to 2001, he led a Cooperative Threat Reduction program in Russia aimed at dismantling obsolete strategic missiles.
1. UN Security Council, S/RES/2087, January 22, 2013.
2. Brian Harvey, Henk H. F. Smid, and Théo Pirard, Emerging Space Powers: The New Space Programs of Asia, the Middle East, and South America (New York: Springer, 2010), p. 448.
3. Barbara Starr, “North Korean Missile R&D Gains New Pace,” Jane’s Defence Weekly, Vol. 21, No. 25 (June 1994): 10; Joseph S. Bermudez Jr., “A History of Ballistic Missile Development in the DPRK,” Center for Nonproliferation Studies Occasional Paper, No. 2 (November 1999), p. 28.
4. “Successful Launch of First Satellite in DPRK,” Korean Central News Agency, September 4, 1998.
5. For details on the rocket’s configuration, see Theodore Postol, “A Technical Assessment of Iran’s Ballistic Missile Program: Technical Addendum to the Joint Threat Assessment on Iran’s Nuclear and Missile Potential,” May 6, 2009, http://docs.ewi.info/JTA_TA_Program.pdf.
6. Doug Richardson, “Transonic Buffeting May Have Doomed Taepo Dong-2,” Jane’s Missiles and Rockets, August 1, 2006.
7. “Misairu sandanmewa koukajini bunri – nichibei suitei” [Third stage of missile separates upon descent: Japan–U.S. assumption], Chunichi Shimbun, April 10, 2009; David Wright and Theodore Postol, “A Post-Launch Examination of the Unha-2,” Bulletin of the Atomic Scientists, June 29, 2009, http://www.thebulletin.org/web-edition/features/post-launch-examination-of-the-unha-2.
8. The third-stage and satellite wreckage may have traveled further downrange. See Wright and Postol, “A Post-Launch Examination of the Unha-2.”
9. Mark Fitzpatrick, “Leap Day in North Korea,” Foreign Policy, February 29, 2012.
10. “Analysis Finds N. Korean April Rocket Launch Complete Failure,” Kyodo News, December 4, 2012.
11. Trajectory modeling by David Wright suggests a similar conclusion. See David Wright, “A Comparison of North Korea’s Unha-2 and Unha-3,” Union of Concerned Scientists, April 8, 2012, http://allthingsnuclear.org/a-comparison-of-north-koreas-unha-2-and-unha-3/.
12. The Nodong engine is powered by a nitric acid oxidizer and a kerosene fuel. The two propellant components are carried by the missile stage in separate tanks. The oxidizer tank for this propellant combination is roughly 1.8 times larger than the fuel tank. The Soviet R-27 submarine-launched missile uses a different propellant combination (nitrogen tetroxide and a hydrazine derivative known as UDMH) that is carried by an oxidizer tank about 1.2 times larger than the fuel tank. The Unha-3 second-stage tank sizes are consistent with the Nodong propellants. For more details, see Markus Schiller, “Characterizing the North Korean Nuclear Missile Threat,” RAND Technical Report, 2012, p. 85, http://www.rand.org/content/dam/rand/pubs/technical_reports/2012/RAND_TR1268.pdf.
13. David Wright, “Debris From North Korea’s Launcher: What It Shows,” Union of Concerned Scientists, December 27, 2012, http://allthingsnuclear.org/debris-from-north-koreas-launcher-what-it-shows/; David Wright, “South Korea’s Analysis of North Korea’s Rocket Debris,” Union of Concerned Scientists, http://allthingsnuclear.org/south-koreas-analysis-of-north-koreas-rocket-debris/.
14. U.S. Mission to the United Nations, “Remarks by Ambassador Susan E. Rice, U.S. Permanent Representative to the United Nations, at a Security Council Stakeout Following Consultations on North Korea,” December 12, 2012, http://usun.state.gov/briefing/statements/201940.htm.
15. The R-7 was too large (weighing more than 270 tons and standing roughly 36 meters tall) and operationally cumbersome. Consequently, its deployment numbers never topped six during the eight years it was in military service. Only one dedicated R-7 ICBM launch pad was constructed, at the Baikonur facility in Kazakhstan, and six to eight were built at the Angara complex located in Plesetsk. In contrast, the R-16, R-36, and UR-100 were deployed in much larger numbers, measured in the hundreds.
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