(CNN)The Pentagon has assessed that North Korea’s weekend missile launch showed new capabilities, US officials told CNN on Monday.
The launch involved the first land-based test of an intermediate-range missile that, in the past, has been fired from a submarine, two US officials said. And because it was launched from a west coast missile site, it flew farther than any previous North Korean tests, about 300 miles before dropping into the Sea of Japan.
“It’s very similar to what they’ve launched from their submarines in the past,” US Navy Capt. Jeff Davis told reporters Monday. “This appears to be a land-based variant of it.”
Significantly, the officials noted that the missile, the Pukguksong-2, used solid rocket fuel, making it harder to detect an imminent launch because it requires less fueling time on the launch pad.
It was described by the Korean Central News Agency, the news service of Pyongyang, as a “surface-to-surface medium long-range ballistic missile” capable of carrying a nuclear warhead.
But many experts think North Korea is far off from being able to put a nuclear warhead on its missiles.
The missile was launched from the Banghyon air base in North Pyongan Province on Sunday morning.
Last August North Korea test-fired what it said was a submarine-launched ballistic missile marked as a Pukguksong-1, a name which translates as “North Star.”
Solid fuel is like an explosive jelly, less corrosive than liquid fuel, and it can be more easily stored in the rocket’s fuel tank that the liquid alternative which require specially lined tanks.
As with other rocket forces, North Korea’s liquid fuel-powered ballistic missiles up until now required a garrison, fuel storage tanks and support vehicles to launch, which can be identified with imagery, experts say.
But solid fuel-powered missiles need much less infrastructure, making them difficult for those monitoring North Korea’s military movements to spot, as there are fewer indicators, such as movement of trucks, for South Korean or US satellites and other surveillance to pick up on.
Two versions of the same missile?
“While North Korean media has stated that both the Pukguksong-1 and -2 are solid-fueled, it was widely presumed that they were based on the liquid-fuelled R-27 ‘Zyb’ Submarine Launched Ballistic Missile that was developed by the Soviet Union in the 1960s,” said Karl Dewey, an expert in chemical, biological, radiological and nuclear weapons with Jane’s Defence Weekly in London.
Dewey told CNN that the different exhaust plumes seen in North Korean imagery of Pukguksong-1 tests had already prompted speculation that there might be both liquid and solid fuel versions of the missile.
The South Korean military has affirmed the North’s claim that solid fuel was used in the latest test.