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Ready for launch?
ANALYSIS NORTH KOREA
Ready for launch? IT HAS been a record year for “It is very likely that North North Korea’s nuclear ambitions. Korea has a nuclear weapon that The secretive nation tested its could hit South Korea or Japan,” fifth nuclear device last month, says Joe Cirincione of the the second test this year and the Ploughshares Foundation, a US largest so far. Remote monitoring think tank. It may soon even be put the underground explosion at able to hit the continental US, 10 to 15 kilotons, about the size of making North Korea a top priority the Hiroshima bomb. Days later, it for the incoming US president. conducted its biggest-ever test of a How can we tell the North’s true long-range rocket booster. capabilities, given its secrecy? “The threat has now reached a dimension altogether different “It is very likely that North Korea has a nuclear from what has transpired until weapon that could hit now,” Japanese prime minister South Korea or Japan” Shinzo Abe told the UN after the nuclear test. “We must thwart North Korea’s plans.” While seismographs record the But how? The North has several explosive power of a bomb, there times agreed to limit its nuclear is no way to confirm its physical plans in return for aid or security size, but we do have clues. guarantees, but these deals have First, we can look to history. always fallen apart. Now the fear is The nation is at a significant point it won’t give up its nukes – unless in its nuclear development, says it collapses, which could be worse. Jeffrey Lewis at the Middlebury Before Kim Jong-un became Institute of International Studies leader in 2011, the nation’s nuclear in Monterey, California. The US, threat seemed constrained. “It UK, China, Russia and France had had limited fissile materials and all shrunk their warheads by their nuclear tests,” says Siegfried fifth tests. North Korea should Hecker at Stanford University in have made similar progress. California, and no way to launch. The nuclear material used Kim accelerated development can also hint at its size. Outside (see timeline, below) and the observers think the last two tests country now claims it can fit were fission bombs boosted by nuclear warheads on missiles. hydrogen isotopes. These release
neutrons in a thermonuclear reaction that produces more explosive force per kilogram of fissile material, usually enriched uranium or plutonium. Satellite images confirm that a plant visited in earlier inspections, which could be used to make the required isotopes, is now finished. The North’s early tests released radioisotopes that could be detected remotely. These showed they were plutonium devices. Hecker, who has visited North Korea’s main nuclear facility in Yongbyon, says it probably has enough plutonium for six to eight bombs and produces another bomb’s worth per year. North Korea also has uranium. Based on satellite images and a 2010 visit to its enrichment plant, Hecker calculates that it has 400 kilograms of highly enriched uranium (HEU), 16 bombs’ worth, and can add six bombs per year.
Smaller warheads The recent underground tests vented no material, so we don’t know what the devices were made of. But descriptions of a warhead released by the country in March suggest it is using nested shells of plutonium, HEU and hydrogen
JEON HEON-KYUN / EPA/CAMERA PRESS
How much should we worry about Kim Jong-un’s nuclear plans and what can we do to stop them, asks Debora MacKenzie
isotopes, says Lewis. “Britain used just such a design in its fifth nuclear test,” he says. This design allows for smaller warheads, and hence more of them. David Albright at the Institute for Science and International Security in Washington DC calculates that Kim now has 12 to 20 nuclear weapons at his disposal. By 2020, North Korea could have 50 to 100, he says, and could field a crude thermonuclear weapon with a yield approaching 100 kilotons. Who could it target? This year saw tests of conventional missiles launched from land and submarine that reached Japanese
North Korea’s nuclear path The nation’s nuclear programme has developed over the past three decades, but has recently accelerated to make 2016 a record year
Failed Known missile tests (incomplete) Nuclear tests (kilotons) Satellite launch 18 | NewScientist | 8 October 2016
US relations break down. Ejects inspectors and resumes plutonium production
<1 kt Failed
UN Security Council expands sanctions
2 kt Failed
Talks cancelled when US president George W. Bush calls it an outpost of tyranny
2010
UN Security Council imposes limited sanctions. Talks resume with US and others
2000
Leaves Nuclear Non-Proliferation Treaty
1990
Agreed Framework signed with US
1980
Nuclear facility built at Yongbyon
6-7 kt 2 Failed
4-6 kt 10-15 kt Success
Kim Jong-un takes over
For daily news stories, visit newscientist.com/news
waters – and could fly further. These short-range missiles could carry warheads that weigh between 700 kilograms and a ton. To hit the US, it needs a lighter warhead, a way to slow it down in flight and heat shields for reentry. Photos released by North Korea in March showed tests of a heat shield and in April it showed off a stationary test of the KN-08, a copy of a Soviet intercontinental ballistic missile (ICBM). This could launch a 500 kg warhead as far as Washington DC, says John Schilling of Aerospace Corporation in California. Flight tests might be only a year away. But North Korea is unlikely to nuke the US, given the chances of a devastating response. Lewis says it only wants ICBMs to deter the US from striking first, as the mobile KN-08 would survive to retaliate. The North is more likely to aim shorter-range weapons at the ports and airports needed to bring in US troops to defend South Korea, he says: “The goal for the leadership is survival, and if troops move in they have nothing to lose.” South Korea has missile defence, but it is only partial.
ultimately failed.” enforcement of sanctions is In 1994, North Korea and the US crucial – and it is unlikely to hurt signed the Agreed Framework. North Korea enough to force The North pledged to give up its concessions, for fear the regime spent fuel, accept inspectors and might collapse. stop plutonium production in “Beijing doesn’t like a nuclear return for nuclear power plants North Korea on its border,” says that make less plutonium. The US Lewis. “But it certainly doesn’t promised no nuclear strikes and want a collapsed nuclear state.” to phase out sanctions. So what can be done? It might “It’s the best deal we could have help if Pyongyang felt less gotten, and we lost it,” says Lewis, threatened, an approach that as George W. Bush took a tougher line. Sanctions remained, the new “There must be talks. power plants were delayed, and in They may not work, but what we have now is 2002 the US accused North Korea guaranteed to fail” of secretly enriching uranium. The year after, North Korea left the agreement, and the Nuclear helped South Africa give up its Non-Proliferation Treaty. nukes in 1989. Last month, North Since then talks have repeatedly Korea’s foreign minister Ri Yong restarted only to be scuppered by Ho said they had “no other choice the North’s reactions to perceived but to go nuclear”, given annual aggression, including satellite US and South Korean military –Stop the bomb- launches condemned by the UN exercises “aimed at... the as banned missile tests (see occupation of Pyongyang”. How do we stop all this? “There “Missile to the moon”, below). It’s not just paranoia. South must be talks,” says Joel Wit at Now the US will talk only if Korea uses a mock-up of Kim JongColumbia University in New York. North Korea agrees to freeze its un’s palace for target practice, “They may not work, but what we programme. The North refuses. and the US has flown a nuclearhave now is guaranteed to fail.” That leaves just trade sanctions capable bomber near its border. Talks almost worked before. to put pressure on the nation. Confronting North Korea in “There have been several efforts Both Donald Trump and Hillary this way is more likely to make that have successfully delayed Clinton want to tighten these. But a conflict go nuclear, says Van North Korea’s nuclear progress,” nearly all North Korea’s foreign Jackson at the Asia Pacific Centre says Albright. “But they business goes via China, whose for Security Studies in Honolulu. Instead, the US and others should de-emphasise nukes in their MISSILE TO THE MOON deterrence, giving North Korea’s North Korea’s declaration in August But now, he says, space and leadership greater security. that it intends to put its flag on the missile development have parted That will be impossible if South moon was greeted with derision. ways. North Korea’s Unha-3 launcher Korea or Japan get their own Experts say their rocket could get has upper stages with small engines nuclear weapons. Domestic there, but a lander is beyond their perfect for putting a satellite in orbit, pressure to do that is growing, current technology. but too weak for an intercontinental and Trump backs a nuclear Japan. Still, the nation looks determined, ballistic missile (ICBM). Philip Jun of the Ploughshares attempting satellite launches despite Foundation fears that a military accusations that they are a front for COVERT OPS miscalculation – say a North missile development. Yet the North’s space ambitions can Korean missile test wildly off Are they? Every nation with a also further its military ones. To make course – could make the heavily space programme once used a nuclear ICBM, the country needs a armed peninsula explode. launchers that doubled as missiles, heat shield to protect the warhead on Despite their spotted history, and China still does, says John re-entry. They could test one talks seem the only option. “No Schilling of Aerospace Corporation covertly, suggests Schilling, by flying country has ever been coerced in California. He thinks North Korea’s it on a “satellite” which falls to Earth. into giving up nuclear weapons, space programme taught it about We could soon see. North Korea but many have been convinced the multi-stage rockets it needs for just tested a larger booster engine to,” says Cirincione. None of them, long-range nuclear weapons. that may launch later this year. however, were rogue states that already had nukes. n 8 October 2016 | NewScientist | 19
Ready for launch? IT HAS been a record year for “It is very likely that North North Korea’s nuclear ambitions. Korea has a nuclear weapon that The secretive nation tested its could hit South Korea or Japan,” fifth nuclear device last month, says Joe Cirincione of the the second test this year and the Ploughshares Foundation, a US largest so far. Remote monitoring think tank. It may soon even be put the underground explosion at able to hit the continental US, 10 to 15 kilotons, about the size of making North Korea a top priority the Hiroshima bomb. Days later, it for the incoming US president. conducted its biggest-ever test of a How can we tell the North’s true long-range rocket booster. capabilities, given its secrecy? “The threat has now reached a dimension altogether different “It is very likely that North Korea has a nuclear from what has transpired until weapon that could hit now,” Japanese prime minister South Korea or Japan” Shinzo Abe told the UN after the nuclear test. “We must thwart North Korea’s plans.” While seismographs record the But how? The North has several explosive power of a bomb, there times agreed to limit its nuclear is no way to confirm its physical plans in return for aid or security size, but we do have clues. guarantees, but these deals have First, we can look to history. always fallen apart. Now the fear is The nation is at a significant point it won’t give up its nukes – unless in its nuclear development, says it collapses, which could be worse. Jeffrey Lewis at the Middlebury Before Kim Jong-un became Institute of International Studies leader in 2011, the nation’s nuclear in Monterey, California. The US, threat seemed constrained. “It UK, China, Russia and France had had limited fissile materials and all shrunk their warheads by their nuclear tests,” says Siegfried fifth tests. North Korea should Hecker at Stanford University in have made similar progress. California, and no way to launch. The nuclear material used Kim accelerated development can also hint at its size. Outside (see timeline, below) and the observers think the last two tests country now claims it can fit were fission bombs boosted by nuclear warheads on missiles. hydrogen isotopes. These release
neutrons in a thermonuclear reaction that produces more explosive force per kilogram of fissile material, usually enriched uranium or plutonium. Satellite images confirm that a plant visited in earlier inspections, which could be used to make the required isotopes, is now finished. The North’s early tests released radioisotopes that could be detected remotely. These showed they were plutonium devices. Hecker, who has visited North Korea’s main nuclear facility in Yongbyon, says it probably has enough plutonium for six to eight bombs and produces another bomb’s worth per year. North Korea also has uranium. Based on satellite images and a 2010 visit to its enrichment plant, Hecker calculates that it has 400 kilograms of highly enriched uranium (HEU), 16 bombs’ worth, and can add six bombs per year.
Smaller warheads The recent underground tests vented no material, so we don’t know what the devices were made of. But descriptions of a warhead released by the country in March suggest it is using nested shells of plutonium, HEU and hydrogen
JEON HEON-KYUN / EPA/CAMERA PRESS
How much should we worry about Kim Jong-un’s nuclear plans and what can we do to stop them, asks Debora MacKenzie
isotopes, says Lewis. “Britain used just such a design in its fifth nuclear test,” he says. This design allows for smaller warheads, and hence more of them. David Albright at the Institute for Science and International Security in Washington DC calculates that Kim now has 12 to 20 nuclear weapons at his disposal. By 2020, North Korea could have 50 to 100, he says, and could field a crude thermonuclear weapon with a yield approaching 100 kilotons. Who could it target? This year saw tests of conventional missiles launched from land and submarine that reached Japanese
North Korea’s nuclear path The nation’s nuclear programme has developed over the past three decades, but has recently accelerated to make 2016 a record year
Failed Known missile tests (incomplete) Nuclear tests (kilotons) Satellite launch 18 | NewScientist | 8 October 2016
US relations break down. Ejects inspectors and resumes plutonium production
<1 kt Failed
UN Security Council expands sanctions
2 kt Failed
Talks cancelled when US president George W. Bush calls it an outpost of tyranny
2010
UN Security Council imposes limited sanctions. Talks resume with US and others
2000
Leaves Nuclear Non-Proliferation Treaty
1990
Agreed Framework signed with US
1980
Nuclear facility built at Yongbyon
6-7 kt 2 Failed
4-6 kt 10-15 kt Success
Kim Jong-un takes over
For daily news stories, visit newscientist.com/news
waters – and could fly further. These short-range missiles could carry warheads that weigh between 700 kilograms and a ton. To hit the US, it needs a lighter warhead, a way to slow it down in flight and heat shields for reentry. Photos released by North Korea in March showed tests of a heat shield and in April it showed off a stationary test of the KN-08, a copy of a Soviet intercontinental ballistic missile (ICBM). This could launch a 500 kg warhead as far as Washington DC, says John Schilling of Aerospace Corporation in California. Flight tests might be only a year away. But North Korea is unlikely to nuke the US, given the chances of a devastating response. Lewis says it only wants ICBMs to deter the US from striking first, as the mobile KN-08 would survive to retaliate. The North is more likely to aim shorter-range weapons at the ports and airports needed to bring in US troops to defend South Korea, he says: “The goal for the leadership is survival, and if troops move in they have nothing to lose.” South Korea has missile defence, but it is only partial.
ultimately failed.” enforcement of sanctions is In 1994, North Korea and the US crucial – and it is unlikely to hurt signed the Agreed Framework. North Korea enough to force The North pledged to give up its concessions, for fear the regime spent fuel, accept inspectors and might collapse. stop plutonium production in “Beijing doesn’t like a nuclear return for nuclear power plants North Korea on its border,” says that make less plutonium. The US Lewis. “But it certainly doesn’t promised no nuclear strikes and want a collapsed nuclear state.” to phase out sanctions. So what can be done? It might “It’s the best deal we could have help if Pyongyang felt less gotten, and we lost it,” says Lewis, threatened, an approach that as George W. Bush took a tougher line. Sanctions remained, the new “There must be talks. power plants were delayed, and in They may not work, but what we have now is 2002 the US accused North Korea guaranteed to fail” of secretly enriching uranium. The year after, North Korea left the agreement, and the Nuclear helped South Africa give up its Non-Proliferation Treaty. nukes in 1989. Last month, North Since then talks have repeatedly Korea’s foreign minister Ri Yong restarted only to be scuppered by Ho said they had “no other choice the North’s reactions to perceived but to go nuclear”, given annual aggression, including satellite US and South Korean military –Stop the bomb- launches condemned by the UN exercises “aimed at... the as banned missile tests (see occupation of Pyongyang”. How do we stop all this? “There “Missile to the moon”, below). It’s not just paranoia. South must be talks,” says Joel Wit at Now the US will talk only if Korea uses a mock-up of Kim JongColumbia University in New York. North Korea agrees to freeze its un’s palace for target practice, “They may not work, but what we programme. The North refuses. and the US has flown a nuclearhave now is guaranteed to fail.” That leaves just trade sanctions capable bomber near its border. Talks almost worked before. to put pressure on the nation. Confronting North Korea in “There have been several efforts Both Donald Trump and Hillary this way is more likely to make that have successfully delayed Clinton want to tighten these. But a conflict go nuclear, says Van North Korea’s nuclear progress,” nearly all North Korea’s foreign Jackson at the Asia Pacific Centre says Albright. “But they business goes via China, whose for Security Studies in Honolulu. Instead, the US and others should de-emphasise nukes in their MISSILE TO THE MOON deterrence, giving North Korea’s North Korea’s declaration in August But now, he says, space and leadership greater security. that it intends to put its flag on the missile development have parted That will be impossible if South moon was greeted with derision. ways. North Korea’s Unha-3 launcher Korea or Japan get their own Experts say their rocket could get has upper stages with small engines nuclear weapons. Domestic there, but a lander is beyond their perfect for putting a satellite in orbit, pressure to do that is growing, current technology. but too weak for an intercontinental and Trump backs a nuclear Japan. Still, the nation looks determined, ballistic missile (ICBM). Philip Jun of the Ploughshares attempting satellite launches despite Foundation fears that a military accusations that they are a front for COVERT OPS miscalculation – say a North missile development. Yet the North’s space ambitions can Korean missile test wildly off Are they? Every nation with a also further its military ones. To make course – could make the heavily space programme once used a nuclear ICBM, the country needs a armed peninsula explode. launchers that doubled as missiles, heat shield to protect the warhead on Despite their spotted history, and China still does, says John re-entry. They could test one talks seem the only option. “No Schilling of Aerospace Corporation covertly, suggests Schilling, by flying country has ever been coerced in California. He thinks North Korea’s it on a “satellite” which falls to Earth. into giving up nuclear weapons, space programme taught it about We could soon see. North Korea but many have been convinced the multi-stage rockets it needs for just tested a larger booster engine to,” says Cirincione. None of them, long-range nuclear weapons. that may launch later this year. however, were rogue states that already had nukes. n 8 October 2016 | NewScientist | 19