South Korea readies solid-fuel rocket launch as rivalry with North intensifies

Seoul is preparing to launch its solid-fuel space rocket — named “Mir” — from a sea-based platform as early as early November, nearly three years after its third and last successful test.

The upcoming fourth launch, originally scheduled for June but postponed for five months, comes shortly after South Korea disclosed its first test launch of a hypersonic glide vehicle (HGV), a sequence of developments that has drawn fresh attention to the technological arms race between the two Koreas.

Solid-fuel rockets can be kept fueled and ready to fire, unlike liquid-fuel systems that generally require more preparation before launch. That advantage makes solid-fuel propulsion a key military technology, particularly for intercontinental ballistic missiles (ICBMs).

The South Korean military successfully placed a roughly 100-kilogram (220 pounds) Earth observation satellite equipped with synthetic aperture radar (SAR) into orbit during Mir's third test in December 2023, using a three-stage rocket.

The upcoming test will feature the full four-stage configuration, which could enable Seoul to launch military reconnaissance satellites more frequently and build a denser satellite network.

A new front in the Korean arms race

The initiative also advances Seoul's push to develop the independent surveillance and reconnaissance capabilities needed to assume wartime operational control (Opcon) from Washington.

North Korea has continued to develop increasingly sophisticated ICBMs since it test-launched the solid-propellant Hwasong-18 in April 2023. Its efforts now extend to the larger Hwasong-19 and the Hwasong-20, which is believed to be a multiple-warhead missile.

In March, Kim Jong-un observed a static-fire test of a carbon-fiber composite solid-fuel engine that Pyongyang claimed generated 26 percent more thrust.

Tensions between the two Koreas have also intensified after Seoul test-launched an HGV. The Blue House publicly acknowledged on Oct. 8 the existence of a hypersonic weapons development program that it had long kept classified. It also released photographs of President Lee Jae Myung observing a test launch at the Agency for Defense Development.

Some saw the move as a pointed warning to North Korea after last month's land mine explosion along the western front on the inter-Korean border. Pyongyang, however, seems to be in denial of Seoul's success.

“It is hard to believe that [South Korea’s HGV] underwent hypersonic flight,” said Jang Chang-ha, director-general of North Korea’s Missile Administration, in a report published Thursday by the regime-controlled Korean Central News Agency. Jang questioned the test's authenticity, as “the outside appearance [of the HGV in the photos] is so clean with its coating paint remaining intact, not stained with any soot.”

The South Korean Defense Ministry countered that domestically developed heat-resistant materials had provided effective thermal protection even at hypersonic speeds, without leaving any soot.

Years in the making, but who leads?

North Korea began testing hypersonic missiles in September 2021 and has since conducted more than 10 tests. Its development efforts have produced a range of short- and medium-range weapons, including the Hwasong-11Ma, Hwasong-11Ma-1 and Hwasong-11Na.

Early tests drew widespread assessments that North Korea had failed to demonstrate the gliding flight capabilities central to hypersonic weapons. More recently, however, signs have emerged that its technology is advancing rapidly.

“North Korea may have benefited from technology exchanges with Russia, a longtime leader in the field,” said a reserved Air Force intelligence officer.

The key to an HGV is its ability to maneuver during gliding flight while maintaining speeds above Mach 5, or roughly 6,100 kilometers (3,790 miles) per hour. Neither of the two Koreas has released detailed performance data, which makes it difficult to compare their technological capabilities.

Seoul, however, met its target gliding flight requirements on its first attempt.

“Pyongyang's sensitive reaction suggests a sense of alarm that Seoul managed to achieve successful gliding flight on its very first try,” said Shin Jong-woo, secretary general of the Korea Defense and Security Forum.

An ongoing fight for superiority

The military advantage hinges on the ability to detect launch preparations early and respond effectively. Solid-fuel rockets and HGVs make surprise launches easier and interception harder, but Seoul and Washington are seen as better positioned to counter such threats through their superior surveillance, reconnaissance and air defense networks.

North Korea, which has limited surveillance capabilities, may not have detected the South’s test launch in real time. Some within the military also argue that North Korea's hypersonic missiles do not necessarily pose an exceptional threat, as combined Korean and U.S. surveillance assets could detect them shortly after launch.

Beyond the Korean Peninsula, competition to develop hypersonic missiles is also intensifying among major military powers, including the United States, China and Russia.

As Russia deploys hypersonic missiles in its war against Ukraine and China expands its own arsenal, the United States has also begun moving toward the operational deployment of its Long-Range Hypersonic Weapon, known as Dark Eagle. The system is reportedly capable of reaching speeds of up to Mach 17, or roughly 20,826 kilometers per hour, and striking targets as far as 2,776 kilometers away.

Washington is also working to field the AGM-183A ARRW, an air-launched hypersonic missile that Trump once touted as a “super-duper missile.”

Russia, which has forged increasingly close ties with North Korea, is considered a pioneer in hypersonic weapons development. In March 2018, Russian President Vladimir Putin unveiled the Kh-47 Kinzhal hypersonic missile and hailed it as an "invincible weapon.”

Russia has also deployed its Zircon hypersonic cruise missile in the war in Ukraine, alongside the Kinzhal. But Ukrainian forces have intercepted both missiles multiple times with U.S.-made Patriot air defense systems, which has raised doubts about whether their battlefield performance lives up to Moscow's claims.

China first unveiled its DF-17 hypersonic missile during a military parade in 2019 to mark the 70th anniversary of the nation's founding. In June this year, Beijing also released footage of a test launch in the Gobi Desert. The missile reportedly has a maximum range of 1,500 to 2,000 kilometers and can alter its flight trajectory at altitudes between 10,000 and 30,000 meters. It also successfully tested an HGV integrated with a fractional orbital bombardment system (FOBS) that uses an orbital trajectory in 2021. Mark Milley, then chairman of the U.S. Joint Chiefs of Staff, expressed concern and likened the test to a "sputnik moment," a reference to the shock the United States experienced when the Soviet Union launched the world's first satellite.

BY LEE YU-JUNG, SHIM SEOK-YONG [[email protected]]