Encyclopedia Astronautica
Unha 3


North Korean three-stage space launch vehicle derived from the Taepodong intermediate range ballistic missile. It is designed to place a 100-kg satellite payload into a 500-km altitude polar orbit, firing south from the new west coast Tongchang-ri space launch site.

In the NOTAM (notice to airmen) issued by North Korea on 19 March 2012, the impact zones of the first and second stages were given as 480 km and 2500 km directly south of the launch site. The first stage impact range indicates that the first stage burnout occurs at over 100 km altitude and a velocity of 2700 m/s. Stage two would burn out at over 250 km altitude and a velocity of 5000 m/s. This would mean the theoretical delta V for each stage, and corresponding masses would be as follows:

  • Stage 1: 80,000 kg fueled, 8000 kg empty, Specific impulse 255 seconds vacuum / 232 seconds sea level, delta V = 4,100 m/s, burnout at 2700 m/s, 120 km altitude, impact 480 km downrange.
  • Stage 2: 7,000 kg fueled, 1000 kg empty, Specific impulse 255 seconds vacuum, delta V = 2,300 m/s, burnout at 5000 m/s, 350 km altitude, impact 2500 km downrange.
  • Stage 3: 2,900 kg fueled, 900 kg empty, Specific impulse 260 seconds vacuum, delta V = 2,800 m/s, burnout at 500 km altitude at orbital insertion.

Despite western press speculation that the Unha 3 could be the basis for an intercontinental ballistic missile that could reach the United States, this three stage rocket is incapable of lofting the payload necessary for that mission. Similarly the American and Soviet analogues (Thor and R-14) could not be upgraded for such a mission. In 1957 Soviet Chief Designer Yangel sold his R-16 ICBM concept to the leadership as simply his R-12 IRBM serving as the second stage to his R-14 MRBM. In fact substantial redesign and repackaging of all elements, and new propellants were necessary to provide a viable ICBM. The same applies to any North Korean design, which would require a new 3-m diameter first stage.

Despite speculation that this launch would be the first test of such a missile, photography at the site by the international media in April 2012 indicated the same design, designated Taepodong-2, was being used as in the prior satellite launch attempt on 4 July 2006. The first orbital launch attempt, on 31 August 1998, used the much smaller 33-metric-ton Taepodong-1.

Status: Active.
Gross mass: 90,000 kg (175,000 lb).
Height: 30 m (100 ft).
Diameter: 2.4 m (8.0 ft).

xunha3.png
Unha 3 compared with other 2.4m diameter space launch vehicles.
xunha3a8.jpg
Unha 3 on the pad.
xunha3b8.jpg
Unha 3 on the pad.



Associated Countries
See also
  • Taepodong North Korean long-range ballistic missile and satellite launch vehicle consisted of a No-Dong 1 IRBM as the first stage, and a derivative of the Scud-C SRBM as the second stage. More...
  • missile Guided self-propelled military weapon (as opposed to rocket, an unguided self-propelled weapon). More...

Associated Launch Sites
  • Tongchang-ri North Korean space launch site, on the west coast, designed for launch into polar orbit or test of intermediate or intercontinental range missiles into trajectories that do not fly over Japan. First pad was operational in April 2012.

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