David Wright

Co-director and senior scientist

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Dr. Wright received his PhD in physics from Cornell University in 1983, and worked for five years as a research physicist. He was an SSRC-MacArthur Foundation Fellow in International Peace and Security in the Center for Science and International Affairs in the Kennedy School of Government at Harvard, and a Senior Analyst at the Federation of American Scientists. He is a Fellow of the American Physics Society (APS) and a recipient of APS Joseph A. Burton Forum Award in 2001. He has been at UCS since 1992. Areas of expertise: Space weapons and security, ballistic missile proliferation, ballistic missile defense, U.S. nuclear weapons and nuclear weapons policy. David also blogs on the Equation.

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David's Latest Posts

Reentry of North Korea’s Hwasong-15 Missile

Photos of the Hwasong-15 missile North Korea launched on its November 29 test suggest it is considerably more capable than the long-range missiles it tested in July. This missile’s length and diameter appear to be larger by about 10 percent than July’s Hwasong-14. It has a significantly larger second stage and a new engine in the first stage that appears to be much more powerful.

While we are still working through the details, this strongly implies that North Korea could use this missile to carry a nuclear warhead to cities throughout the United States. A final possible barrier people are discussing is whether Pyongyang has been able to develop a reentry vehicle that can successfully carry a warhead through the atmosphere to its target, while protecting the warhead from the very high stresses and heat of reentry. Read more >

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Did Pilots See North Korea’s Missile Fail during Reentry?

News reports say that a Cathay Airlines flight crew on November 29 reported seeing North Korea’s missile “blow up and fall apart” during its recent flight test. Since reports also refer to this as happening during “reentry,” they have suggested problems with North Korea’s reentry technology.

But the details suggest the crew instead saw the missile early in flight, and probably did not see an explosion. Read more >

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North Korea’s Longest Missile Test Yet

After more than two months without a missile launch, North Korea did a middle-of-the-night test (3:17 a.m. in Japan) today that appears to be its longest yet.

Reports are saying that the missile test was highly lofted and landed in the Sea of Japan some 960 km (600 miles) from the launch site. They are also saying the missile reached a maximum altitude of 4,500 km. This would mean that it flew for about 54 minutes, which is consistent with reports from Japan.

If these numbers are correct, then if flown on a standard trajectory rather than this lofted trajectory, this missile would have a range of more than 13,000 kilometers (km) (8,100 miles). This is significantly longer than North Korea’s previous long range tests, which flew on lofted trajectories for 37 minutes (July 4) and 47 minutes (July 28). Such a missile would have more than enough range to reach Washington, D.C., and in fact any part of the continental United States.

We do not know how heavy a payload this missile carried, but given the increase in range it seems likely that it carried a very light mock warhead. If true, that means it would be incapable of carrying a nuclear warhead to this long distance, since such a warhead would be much heavier.

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Don’t Make the Same Mistake on Iran that Bush Made on North Korea

Press reports say President Trump will likely not certify Iranian compliance with the Iran nuclear deal in the near future, setting up a situation in which Congress can reimpose sanctions and effectively end US compliance with the deal. Read more >

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North Korea’s Sept. 15 Missile Launch over Japan

North Korea conducted another missile test at 6:30 am September 15 Korean time (early evening on September 14 in the US). Like the August 28 test, this test appears to have been a Hwasong-12 missile launched from a site near the Pyongyang airport. The missile followed a standard trajectory—rather than the highly lofted trajectories North Korea used earlier this year—and it flew over part of the northern Japanese island of Hokkaido (Fig. 1). Read more >

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