Chinese vessels have been active around splashdown locations for the space rocket that North Korea launched last week, NK Pro analysis shows, in what experts said may be an effort to recover debris from the DPRK launch vehicle and the spy satellite it failed to put in orbit.

The DPRK launched the Malligyong-1 reconnaissance satellite aboard a Chollima-1 carrier rocket from its northwest coast early on Aug. 24. But the rocket failed “due to an error in the emergency blasting system during the third-stage flight,” according to North Korean state media.

Japan’s defense ministry assessed