North Korean Satellite Tumbling and now Space Debris

Kwangmyongsong-3, the North Korean satellite launched into space by the Unha-3 rocket last week, is out of control and most likely dead, astronomers reported Monday.

The apparent failure will not cause the spacecraft to fall quickly back to earth but represents a major setback in Pyongyang’s bid to portray the launching as a patriotic and technological success.

“It’s tumbling and we haven’t picked up any transmissions,” said Jonathan McDowell, a Harvard astronomer who tracks global rocket launchings and space activity. “Those two things are most consistent with the satellite being entirely inactive at this point.”

North Korea’s state-run press, which was preoccupied on Monday with reporting on the somber one-year anniversary of the death of Kim Jong-il, the longtime leader, said nothing about the satellite’s dysfunction.

It has been describing the satellite launch as a triumphal achievement of Mr. Kim’s successor, his son Kim Jong-un, done in the face of worldwide criticism and United Nations sanctions on the North’s ballistic missile program.

The satellite, said to be about the size of a washing machine, reportedly carries an onboard camera to observe the earth. That mission requires the spacecraft’s orbit to be rock-steady.

Dr. McDowell said the tumbling implies that onboard systems meant to control and stabilise the craft had failed.

He added that radio astronomers had picked up no signals from the satellite and that optical astronomers had observed it brightening and dimming as it slowly tumbled end over end.

“It’s clear that the rocket part of this mission worked very well for the North Koreans,” Dr. McDowell said in an interview.

“They ended up in the right orbit. But the preponderance of the evidence suggests that the satellite failed either during the ascent or shortly afterwards.”