An Unha-3 rocket being launched in December 2012

An Unha-3 rocket being launched in December 2012 KCNA/AP

Images Indicate N. Korea Carried Out Long-Range Rocket Test

The reclusive state has been working and developing a rocket engine

A new expert analysis of satellite photographs strongly suggests that North Korea tested an engine for one of its long-range rockets sometime this spring -- a development that has implications for its work on ICBMs.

The Wednesday report by 38 North -- a website that closely tracks developments in North Korea -- looked at space reconnaissance photographs taken between March and May. The analysis said there was a chance the rocket motor test was for development of the long-range Taepodong 3 missile or an updated version of the Unha space rocket, which is based on the Taepodong.

"The recent engine test indicates that Pyongyang continues to move forward with its [space-launch vehicle] and long-range missile programs despite continuing United Nations sanctions and China's public expressions of displeasure with the North's efforts to further develop nuclear weapons and the missiles to deliver them," said 38 North, which is run by the U.S.-Korea Institute at Johns Hopkins University.

Satellite photographs taken in mid-April showed potential propellant containers placed on the launch platform at the Dongchang-ri missile complex, not far from the North's western coast. Another photo taken on May 16 did not reveal any operations around the platform, though a notable orange discoloration could be seen in the flame trench. The color matched the discoloration left behind by the fuel used by Pyongyang for its two 2012 Unha rocket launches at the missile site, indicating that the rocket test had already taken place, according to 38 North image analyst Nick Hansen.