North Korea hints at better missiles

SEOUL, SOUTH KOREA — North Korea’s state news media released a photograph Wednesday suggesting the North was working on a more powerful solid-fuel ballistic missile and said the country’s leader, Kim Jong Un, had ordered the production of more rocket engines and warheads.

Unlike liquid-fuel rockets, solid-fuel missiles do not have to be loaded with fuel just before launching, a process that can take as long as an hour and make the missile vulnerable to a pre-emptive strike. Such missiles are also easier to transport and hide.

Kim gave his order to bolster the country’s missile arsenal during a visit to the Chemical Material Institute of the Academy of Defense Science, the North’s official Korean Central News Agency said, without disclosing when the visit took place.

It said the institute was responsible for producing fiber and carbon compound materials used to build highpower rocket engines and so-called re-entry vehicles for ballistic missile warheads.

Building a reliable re-entry vehicle, which allows a warhead to survive the intense heat and friction of re-entering the atmosphere, is one of the most difficult hurdles to clear in building an intercontinental ballistic missile, or ICBM. Kim said his country had proved its mastery through recent missile tests, including two ICBM launchings last month.

In its most recent test of its Hwasong-14 ICBM, on July 28, North Korea demonstrated that the missile could reach major cities in the middle of the continental U.S., analysts said. But South Korean intelligence officials and other analysts still doubt that the North has mastered re-entry technology.