Key facts
- North Korea's missile chief cited a lack of soot on the vehicle as evidence against hypersonic flight.
- South Korea's Defense Ministry said the missile's heat-resistant materials accounted for its clean appearance.
- Hypersonic weapons are characterized by speeds over five times the speed of sound and maneuverability.
North Korea's missile chief, Jang Chang Ha, questioned the validity of South Korea's recent hypersonic glide vehicle test, suggesting it did not achieve hypersonic speeds. State media reported that Jang cited the clean exterior of the vehicle in released photographs as evidence against claims of extreme heat associated with hypersonic flight. South Korea's Defense Ministry countered that the missile was constructed with heat-resistant materials, which prevented soot accumulation. The ministry affirmed its commitment to further developing the weapon, a key strategic asset. Hypersonic weapons are defined by their speed, typically exceeding Mach 5, and their maneuverability, which aids in evading missile defenses. South Korean President Lee Jae Myung had previously overseen the country's first hypersonic test-firing amid rising tensions on the Korean Peninsula.