Solid-fuel space launch vehicle

South Korea's solid‑fuel space launch vehicle, commonly abbreviated GYŪB (Korean: Goche Yeonlyo Uju Balsache or 고체연료 우주발사체), is an orbital booster under development by the state-run Agency for Defense Development (ADD). It is based on solid propellant stages, with a liquid-fuel post‑boost stage (PBS), designed to deploy small satellites—particularly synthetic aperture radar (SAR) reconnaissance payloads—into low Earth orbit as part of the country's independent space-based surveillance capability.^[1]

ADD plans the first launch of a complete version of the launcher, capable of placing a one-ton satellite into a sun-synchronous orbit , in 2027. By 2032, the military expects to have a version capable of placing 7 tonnes into a sun-synchronous orbit and 3.7 tonnes into a geostationary transfer orbit.^[1][2]

Technical details

The rocket has three solid‑fuel stages, followed by a liquid‑fueled fourth "post‑boost" stage (PBS) to enable precise payload deployment.^[1][3][4][5] The first stage is mentioned to produce "a thrust that is one-and-a-half times stronger than North Korea’s solid-fuel engines", or around 245 tones.^[6] The second stage produces 75 tons of thrust. The GYŪB‑TV2 version, launched in December 2023, had an estimated take-off thrust of 170 tonnes with the capacity to place 700 kilograms in low orbit.^[2][1]

GYŪB orbital launcher versions^[1][2]

Version	Year	1st stage	2nd stage	3rd stage	4th stage	Thrust (t)	Payload to sun-synchronous orbit (t)	Payload to geostationary transfer orbit (t)
GYŪB TV2	2023	Active	-	Active	Active	170	.7
GYŪB	2027	Active	Active	Active	Active		1
unnamed	2032						7	3.7

Flight history

Two suborbital launches of a version called TV1 (Test Vehicle 1), comprising only the last three stages, were carried out in 2022 from Anhueng.^[1] TV2 is an incomplete version of the final launch vehicle, consisting of only the 1st, 3rd, and 4th stages. It was launched on December 4, 2023, from a barge off Jeju Island.^[1][3][5][2]

• March 2022: GYŪB‑TV1 (1) - First suborbital test using a live stage 2, a inert stage 3, and a live PBS.^[1]
• December 2022: GYŪB‑TV1 (1)- Second suborbital flight with live stage 2, 3 and PBS.^[1]
• December 4, 2023: GYŪB‑TV2 - First orbital launch, using stage 1, stage 3 and PBS, successfully placing a 100 kg SAR satellite ("Doory‑Sat" built by Hanwha Systems) into a 650 km orbit.^[1][3][5][2]