Is North Korea’s Rocket a Space Launch Vehicle or An ICBM?

Analysts at 38North have a good posting up about why the Unha-3 rocket that North Korea has threatened to launch again is likely intended for space launch purposes:

But if the Unha-3 is intended for use as an ICBM, it’s not a very good one. The second- and third-stage engines don’t have enough thrust to efficiently deliver heavy warheads; a militarized Unha might deliver 800 kilograms of payload to Washington, DC. The North Koreans can probably make a nuclear warhead that small, but it would be a tight fit. With bigger upper-stage engines, which we know the North Koreans have, they could deliver substantially larger payloads. This would allow bigger and more powerful warheads, more decoys to counter US missile defenses, and a generally tougher and more robust system.

The Unha is also too heavy and cumbersome to be survivable in wartime. Too big for any mobile transporter, it can only be launched from fixed sites. Its highly corrosive liquid propellants require hours of pre-launch preparations. That’s a bad combination for North Korea; their fixed launch sites are going to be watched very closely, and particularly in a crisis, any indication that an ICBM is being prepared for launch could trigger a pre-emptive strike.

The same could be said of the old Soviet R-7. As an ICBM, it was pretty much a dud—the USSR never deployed more than 10, and retired them after less than a decade. As a space launch vehicle, its descendants are still in service today.

The North Koreans could press the Unha-3 into limited service as an ICBM, just as the USSR did with the R-7—a temporary measure, until something better is available. They can almost certainly build something better, and they appear to be trying. The KN-08 missile mock-ups, twice paraded through Pyongyang, are exactly the sort of thing a nation like North Korea would build if it wanted to use its eclectic mix of early 1960s rocket technologies to build an ICBM. It is small enough to be mobile and therefore survivable but with the performance (barely) to reach the enemy’s homeland. The Unha-3, by comparison, looks like it was designed to launch satellites rather than warheads.  [38North]

It is worth reading the whole thing at the link.