The satellite North Korea launched into space earlier this week has achieved orbit, but whether it is operating normally has not been verified, the Defense Ministry said Tuesday.

On Sunday, the North launched a rocket carrying the Kwangmyongsong-4 satellite, but the outside world viewed it as a cover for testing the country's intercontinental ballistic missile technology.

The North Korean rocket was the same shape as the Unha-3 rocket the communist country launched in December 2012, a ministry official said in an analysis of the recent North Korean test.

"The proportion of the long-range missile's diameter and length is 2.4 to 30, the same (as the previous rocket)," he said.

Whereas the satellite the North sent into orbit in 2012 weighed about 100 kilograms, the one launched this time was heavier, the official said.

Given the identical size and trajectory as well as the similar payloads, the latest rocket appears to be of the same specification as the rocket launched four years ago, he noted, adding that there has been "little technical progress" in the missile development.

Currently, the North is presumed to be in possession of a long-range missile with a maximum range of 12,000 kilometers with the capacity to carry a payload weighing about 250 kg, he said.

The latest addition of one more successful test may have bolstered the "stability" of the missile and "credibility" of the missile's components, according to the official.

In the initial analysis of the recent North Korean launch, the ministry also concluded that the three-stage rocket successfully separated all of its three stages before putting the satellite into orbit.

After the rocket lifted off at the Dongchang-ri launch site in the northwest Sunday morning, South Korea's Aegis destroyer detected the rocket shedding its first stage in the Yellow Sea and the pairing in waters southwest of Jeju Island.

But the South Korean radar lost track of the rocket right after the pairing separation stage.

The official said the second stage may have fallen in waters east of the Philippine island of Luzon, citing the fresh result of a simulation analysis.

"The locations where the first, second stages and the pairing landed are the same as those of Unha-3," another official said.

Despite the recent test, North Korea has not achieved the critical "re-entry" technology needed to bring a ballistic missile that was fired into space back into the atmosphere, he said.

Now the North Korean satellite is orbiting and passing above South Korea four times a day.

But it has yet to be verified whether the satellite is sending signals properly, the official said, suggesting the latest North Korean launch was a long-range missile test disguised in a peaceful space vehicle launch.

Currently, the satellite and the third stage are rotating in their orbits, but the third stage will soon lose its orbit and burn up, he said, adding that whether the satellite will keep its orbit should also be verified down the road.

(Yonhap)