Defense Ministry rebuffs North Korea's doubts about hypersonic glide vehicle test

South Korea's Ministry of National Defense has rebuffed North Korea's claims questioning the performance of its hypersonic glide vehicle (HGV) test, saying the vehicle's clean exterior — which Pyongyang cited as evidence of doubt — in fact demonstrates the success of domestically developed heat-resistant materials and design.

A Defense Ministry official said Friday that the absence of soot on the vehicle's surface should be seen as a sign of technological achievement, not failure. "I think the fact that there is no soot is itself the technology," the official said in response to North Korea's allegations.

The ministry said the HGV, launched in South Korea's first-ever test of such a vehicle, was built on domestically produced heat-resistant materials with superior thermal durability and robust structural design, enabling it to withstand hypersonic flight conditions without surface scorching. The ministry added that it plans to further advance related technologies as it moves toward weaponizing the HGV, which it described as a core strategic asset for future national security.

The North Korean claims came Thursday, when Jang Chang-ha, director general of North Korea's missile administration, questioned in a KCNA interview whether the vehicle had actually achieved hypersonic flight, citing photos of the test that the South Korean government had released.

Jang said a photo showing the vehicle plunging nearly vertically just before hitting the sea revealed no soot or paint discoloration on its surface — something he said was impossible to reconcile with the extreme heat generated during hypersonic flight. He used the observation to cast doubt on South Korea's announcement that the test had been a success.

The HGV's first test launch took place Oct. 8 at a maritime barge within the Anheung Test Range of the Agency for Defense Development in Taean, South Chungcheong Province, with President Lee Jae Myung in attendance.

Cheong Wa Dae said at the time that the vehicle had ascended to its target altitude, separated successfully, and completed its planned flight path without incident under hypersonic conditions.