John Schilling
February 9, 2016
North Korea’s Space Launch: An Initial Assessment
At first glance, North Korea’s launch of an Unha Space Launch Vehicle (SLV) on February 7, 2016, looks very much like a repeat of its successful launch a little over three years ago. In fact, a close examination reveals that the North appears to have used some stock footage of the 2012 launch in its announcement this time around. But there are also images of a rocket launching from the new gantry that North Korea completed only last year. Moreover, the US Joint Space Operations Center (JSpOC) has released the orbital elements of two new bodies in stable orbits, with the identifiers “KMS-4” for the Kwangmyongsong-4 satellite and “Unha 3 R/B” for the launch vehicle’s upper stage rocket body. In short, this is not a hoax.
Images of the rocket departing the launch pad indicate an overall length of about 30 meters, the same as the Unha-3 rocket from North Korea’s 2012 launch. To the extent that we can tell from low-resolution images, the shape and the engine exhaust plumes are also nearly identical. North Korea did politely tell the mariners and airmen of the world where to expect the expended rocket stages to fall, and these also match the 2012 launch. The satellite itself is in a very similar orbit to 2012. While many had expected North Korea to debut a new and larger rocket, and the new launch pad was clearly built for a larger rocket, that launch is still in the future. North Korea might call this new rocket an Unha-4, but it is almost certainly an Unha-3 with, at most, minor modifications.
Several early reports indicated that the launch had failed, some saying that the first stage was seen on radar to have exploded; others that the rocket disappeared from radar shortly after the payload shroud had separated. These are common times for failure, and yet the satellite is in orbit. Most likely the rocket disappeared from radar at about the time it was passing out of range, with perhaps a moment of confusion while radar tried to track the payload shroud rather than the rocket.
But it does seem likely that the first stage did explode-after safely separating from the rocket. That’s a change from the 2012 launch, where the first stage fell into the ocean relatively intact and was recovered by the South Korean Navy. This could have been a late malfunction or a reaction involving unburnt residual propellant, but it could also be that the North Koreans didn’t want their southern neighbors to get quite so good a look at their rocket this time. Self-destruct mechanisms are frequently added to stages for “range safety,” to make sure no wayward rocket can land on a populated area, and it would be little trouble to deliberately activate one as soon as the first stage has done its job. Whatever minor modifications the DPRK may have made to the first stage will likely remain obscure.
Assume for the moment that North Korea is sincere in its claim that it just want to launch satellites. They are calling this one the “Kwangmyongsong-4,” and saying it is an Earth observation satellite. This is plausible enough, though “Earth observation” covers everything from improving weather forecasts and crop yields to military reconnaissance and targeting. North Korea’s first satellite accomplished little, tumbling out of control shortly after launch. At this point, North Korea would probably consider it a win if its satellite could hold a stable attitude, communicate with the ground and send back a few pictures…Read on.
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