With recent activity at the Sohae Satellite Launching Station, an American research institution has concluded that North Korea may have more powerful, longer-range rockets it can test by year’s end.

The report by 38 North, the website of the U.S.-Korea Institute at the Johns Hopkins School of Advanced International Affairs, said that satellite imagery from the station indicates that a number of construction projects there are nearing completion. The result, the report said, may be that the North can carry out tests of “space launch vehicles” with “greater ranges and larger payloads” than was the case when the North test-launched