North Korea's recently launched satellite has achieved stable orbit but is not believed to have transmitted data back to Earth, US sources said of a launch that has so far failed to convince experts that Pyongyang has significantly advanced its rocket technology.Sunday's launch of what North Korea said was an earth observation satellite angered the country's neighbors and the United States, which called it a missile test. It followed Pyongyang's fourth nuclear test in January."It's in a stable orbit now. They got the tumbling under control," a US official said on Tuesday.That is unlike the North's previous satellite, launched in 2012, which never stabilized, the official said. However, the new satellite was not thought to be transmitting, another source added.