Do the North Koreans have more information about their test launch than we do?

Do the North Koreans have more information about their test launch than we do?

Do the North Koreans have more information about their test launch than we do?

Answers to your questions about the news.
April 6 2009 7:34 PM

It's 11:48 a.m. Do You Know Where Your Missile Is?

Do the North Koreans have more information about their test launch than we do?

North Korea attempted to launch a satellite into orbit with a three-stage missile Sunday. The U.S. Northern Command, which monitored the launch using a global network of radars, satellite-mounted spy cameras, and satellites equipped with infrared sensors, concluded that the satellite fell into the Pacific Ocean. The North Koreans insist that the satellite achieved orbit and is broadcasting patriotic music to the world. Do they have better data than we do, since it's their missile?

Not really. The only unique information the Democratic People's Republic of Korea may have had was performance data broadcast from the missile, more useful in determining why a test failed than whether it failed. For the North Koreans to verify a successful delivery of the satellite into orbit, they would need to observe the skies just like everyone else. Since Pyongyang has access to tracking equipment only within North Korean borders, its view is far more limited than those of other countries—the North Koreans would not have known that the satellite was safely in place until it had passed overhead few times in a stable trajectory over a span of several hours. (The United States, by contrast, gathers information from ground- and sea-based radar devices around the world and could have spotted the satellite within a matter of minutes, no matter where it entered orbit.)

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On the other hand, the North Koreans may have had some data on the launch that the West is missing. Broadcasting devices installed on the missile itself send back status reports as the test flight unfolds. In U.S. missile tests, scientists receive these transmissions throughout missile's trajectory, but the North Korean technology is more limited: Since testers cannot easily place receivers outside their borders, the status reports are sent only while the missile remains within a limited range. It's likely that Pyongyang had reports on Sunday about the test missile's acceleration, vibration, temperature, and pressure at key locations as well as its fuel-pump performance and fuel consumption. But whatever problem caused the missile to fail might have arisen after it had traveled out of reach of the North Korean receivers. (The United States may also have been able to intercept and decode the transmitted data.)

Got a question about today's news? Ask the Explainer.

Explainer thanks Laura Grego and David Wright of the Union of Concerned Scientists and Ivan Oelrich of the Federation of American Scientists.

Brian Palmer covers science and medicine for Slate.