A U.S. aerospace engineer says the new North Korean KN-08 intercontinental ballistic missile is likely to comprise three stages.
 
38 North, a research body affiliated with Johns Hopkins University, published a recent report by John Schilling of the Aerospace Corporation which said that the first stage of the KN-08 consists of four Scud engines. 
 
The report said the second stage is equipped with an engine used in the R-27 mid-range ballistic missiles developed by the Soviet Union, while a set of R-27 vernier thrusters make up the third stage. 
 
Schilling presumed the KN-08 to be 17-point-one meters long with a diameter of one-point-nine meters. The North first displayed the KN-08 in 2012, but has not yet conducted any tests.