This post is from March 2009. Facts and links may have changed since. See more from that month

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DPRK’s Stay Clear Zones

North Korea has declared the stay clear zones ( as pointed out by a number of people in the comments to my alert post). You can down load a Google Earth file of these stay clear zones here. These zones imply that North Korea is launching its rocket due East.

If its fired due East, why do the zones appear to tend to the South?
Before people get excited about this, you have to realize that a launched object remains in a plane that passes through the launch point and the center of the Earth. This plane’s intersection with the Earth’s surface at the launch point forms a line that, in this case, appears locally to go directly East-West. Once you get away from the launch point, the intersection of the plane appears to fall to the South (if the launch point is in the Northern hemisphere) Believe me, this is entirely consistent with a launch due East that takes full advantage of the Earth’s rotational speed.

Why stay clear zones? (Update)
North Korea issued these two stay clear zones to protect shipping etc. from the first and second stages as they reenter, which implies of course, that if the rocket is intended to orbit a satellite that it has three stages.

Geoff Forden

Writing on ACW 2008–2010

Dr. Forden has been at MIT since 2000 where his research includes the analysis of Russian and Chinese space systems as well as trying to understand how proliferators acquire the know-how and industrial infrastructure to produce weapons of mass destruction.

All posts by Geoff Forden