We asked David Schmerler, a research associate at the James Martin Center for Nonproliferation Studies (CNS), Middlebury Institute of International Studies at Monterey, to analyze state media images of the launch and previous photos of what we now know is the Hwasong-12.
The Hwasong-12 was test-fired in the early hours of Sunday, May 14, from the town of Kusong near North Korea's west coast.
"This is the first successful test (of this type of missile) that we know of," Schmerler said.
"One of the big takeaways is the missile's performance, which might give credit to their own design capability. It outperformed previous, copied missile designs, which means that their ballistic missile program is moving at an accelerating rate," he said.
State media reported that North Korean leader Kim Jong Un oversaw the test launch of missile.
He was photographed reading what appears to be a map illustrating the flight plan and anticipated splashdown location of the rocket off the coast of Russia.
The map appears to show the steep arc of the launch trajectory. North Korea claimed the missile reached an altitude of 2,111.5 kilometers (1,312 miles) and flew 787 kilometers (489 miles).
Analysts estimated its range as 4,500 kilometers (2,796 miles), which would put the US territory of Guam in the western Pacific within its reach.
Images released before the launch show the prepared rocket, painted yellow and black. Schmerler pointed out the telemetry antenna on the missile's nose cone, which sends data on the test back to the ground.
"We saw similar antennae on the Musudan during its first successful test," Schmerler said. The Musudan is an intermediate-range ballistic missile (IRBM) with a range of 3,500 kilometers (2,174 miles).
The images also show a retro rocket -- a small solid fuel motor that fires in the opposite direction to the missile's direction of travel. Once it reaches a designated point, the nosecone is designed to separate from the main body of the missile, Schmerler said.
The constituent parts of the Hwasong-12 "seem to be uniquely North Korean," Schmerler said -- possibly designed from scratch by North Korean engineers, rather than designs based on older Soviet missiles.
Schmerler said the rocket appears to be a single stage design. Its performance may suggest otherwise, however. Although, no available data so far shows it was a multi-stage rocket.
North Korea gave a clue of what was to come in the Day of the Sun military parade in April. At the time, the Hwasong-12 had not yet been seen by North Korea watchers. The new weapon appeared to be longer than the Musudan, and had a nosecone similar to that of North Korea's KN-08 intercontinental ballistic missile (ICBM).
It was transported on the same type of transporter as the older missile.
Powered by new engine?
Sunday's launch was possibly connected to an engine test
that took place at Sohae, North Korea's west coast satellite launch site, in March of this year, Schmerler said.
Images released by state media show North Korean leader Kim Jong Un, also at that test, which featured an engine "of a design that we hadn't seen before," Schmerler said.
The engine design features a large central engine surrounded by four vernier thrusters, which swivel round a point to precisely correct the rocket's attitude.
"After the engine test the North Koreans said that the world would soon see its significance," Schmerler said.
"This test, with the new engine configuration, which seems to be more unique to North Korea, outperformed its previous missile tests."
The Hwasong-12 missile launched Sunday was notable in part for its performance -- it was the highest missile test that North Korea has conducted for a weapons-oriented system -- only its previous satellite launch went higher.
"The North Koreans aren't going to test these at full range, they'd have to (fly them) over Japan to do so. They've done it before, but they're shying away from that now. (Instead they're) lofting them as high as they can -- they can calculate the full range from there."
Identifying regime's military assets
Schmerler says that identifying the missiles from state media images has become more difficult.
The missiles "used to have serial numbers that were uniform from previous parades, so we had a guide to identify missiles. In this most recent parade they've thrown away that pattern. We are still trying to figure out their new system."
He says that it is hard to tell how many of the Hwasong-12 missiles the regime has. One way to ascertain that number, however, would be to count the number of launch vehicles they have purchased.
"They only have a finite number of these transporter erector launchers (TELs)," Schmerler says. "There is no evidence that they can manufacture them, and they don't want to burn through their trucks (during missile tests)."
He said images on state media showed the North Koreans parked the vehicle over a test platform, unloaded the missile and then drove the vehicle away.
"We've seen them launch directly from the vehicles before. There isn't necessarily a difference in (the missile's flight) performance, but it makes the setup a little more complicated." On a practical level, he says, this method of launching restricts the mobility of the missile.