jueves, abril 12, 2012

Failure is an option for North Korea satellite ...  then what?

By NBC News space analyst
Special to MSNBC
Officially, we now are only hours from North Korea's launch of its Kwangmyongsong-3 satellite. The first of four reserved daily launch windows has already passed, with three to go until Monday.
Celebrations are already planned that involve a successful mission. The radio beacon is to transmit hymns in honor of the country’s ruling dynasty. Foreign displeasure of the demonstration of rocket prowess will be ignored.
All that is planned — if the launch works. But what if it doesn’t? What if the Earth-observing  satellite goes the way its two predecessors apparently did — into the ocean, as scorched shrapnel,  following a launch failure?
This is worth serious consideration, since the things I’ve seen and assessed during our amazing insider tour of the North Korean space program have made me a lot more worried about the likelihood of this launch succeeding.
Kinds of failures A lot will depend on just how and when the failure occurs.
In the first moments of flight, as the rocket lifts off the pad at the new Sohae launch base , it could explode, as early rockets in many other countries did.
But this may not be as easily detectable as it seems, especially if the video transmission from the launch site has been tape-delayed in prudent anticipation of exactly such a possibility. In that case, "no news" is all the news there will be, until a later announcement that the launch has been "indefinitely postponed."
Local residents north of the base — and we saw lots of villages there — would notice the explosion, but might not even connect it with a rocket. And rumors would be unlikely to spread very fast in such a tightly controlled society.
After a minute or so of flight, the rocket will be high in the skies over the western half of the country, including the capital, Pyongyang. Any "energetic event" (NASA’s favorite euphemism for a bad-ass explosion) could streak the sky with a burst of flame — but no sound.
Lots of people would see it, and some foreign visitors might even get a picture. But these photographs and videos would be recognized for what they showed only if the launch was announced within a minute of liftoff.
These possibilities underscore the importance of the North Koreans announcing the launch time in advance, and broadcasting the launch video with minimum delay — or all their vaunted "transparency" involved with the unprecedented press tour evaporates.
Out of sight, out of luck Another opportunity for failure would come after a well-publicized liftoff, after the vehicle vanishes over the southern horizon. The critical third-stage burn, which apparently involves a fairly sophisticated sideways jog to slip into the proper final orbit, may be too far away for in-country tracking sites to receive signals. So instead they have to wait.
The wait could be excruciating, because the satellite’s orbit does not pass within radio range of North Korea for 11 hours. This is a real situation — I’ve checked the orbital flight path myself — and it’s caused by the steep polar orbit of the vehicle.
During all this time, officials say, the satellite will be transmitting patriotic hymns on a 470MHz  beacon. Foreign radio listeners will try to pick it up, and if the satellite reaches orbit, it’s almost certain that some — perhaps very, very many — will do so before the first official North Korean reception.
If nobody hears the satellite’s beacon in those hours, something clearly will have gone wrong.
Observers also need to be cautious about inevitable rumors and "false positives" — possible confirmatory signals picked up briefly or weakly, that actually originated with our unrelated transmitters. This happens often enough to mislead observers to eager to find and trumpet a "first signal," so we need to be cautious. More >>

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