North Korea restarted major upgrades on a factory suspected of producing tanks and missile launchers in recent weeks after years of delays, satellite imagery shows, signaling Pyongyang’s renewed interest in diversifying launch methods and mass-producing a new tank design. 

Workers appeared to begin installing roofing over a new manufacturing building at the Kusong Tank Plant between Oct. 15 and 19, according to Planet Labs imagery, and this work continued through Oct. 25. The new facility is double the size of the one that was already on the site.

Dave Schmerler, a senior research associate at the James