Singijeon Singijeon or Shinkichon ( " magical machine arrows " ) was a type of Korean ( Joseon ) fire arrow rocket , used during the Joseon Dynasty ( 1392 - 1897 ) . Multiple Singijeon could be launched by hwacha ( multiple rocket launcher ) . History . During the late 1300s , in order to gain ascendancy at sea against Japanese pirates ( wokou , also kaizoku or wako ) , fire arrows called " hwajeon or hwajon " were used , which were the predecessor of the sinijeon . The Koreans had tried to acquire rockets and gunpowder and their production methods from China . The Chinese , however , regarded the technology of gunpowder as a state secret and restricted access to it and trade in its nitrous raw materials ( which could only be found in China ) . The Koreans therefore sought to acquire the manufacturing secrets of gunpowder for themselves and , in 1374 ( ~ 1376 ) , Choe Mu - seon was able to bribe a Han Chinese merchant to obtain the secret formula for manufacturing gunpowder , as well as technical knowledge about Chinese firearm and cannon technology . He also successfully extracted potassium nitrate from the soil and rocks from Japanese trade routes , and developed Korea ' s first gunpowder . The Singijeon saw most of its early use in the Northern borders of Joseon , in the campaign to expand its northern borders by driving out the " Orangkae " ( " Barbarians , " especially referring the Jurchen people ) . Later , its uses expanded to coastal defense against Japanese pirates and was much used throughout the conflicts during the Joseon Dynasty . During the Imjin War , General Gwon Yul attributed his successful defence of the Haengju mountain fortress against numerically superior Japanese forces to the Singijeon . Details of the singijeon were not known until very recently . Korean historians had found the schematics added as an appendix in the book " Gukjo Orye Seorye " ( 국조오례서례 , 國朝五禮序例 ) but did not realize what they were until Dr Chae Yeon - suk identified them as the lost schematics of the singijeon . The schematics detail the lengths of wooden materials , using units down to 0 . 3mm . The schematics are one of the best representations of the acute scientific understanding of the Joseon Dynasty . Overview . Singijeon were divided among three major types : large , medium , and small . The 52 cm long rocket was launched individually on a handheld gun , and the launch was initiated by a fuse in the tube . Even after launch , the fuse would remain in the tube , consuming the black powder until it hit the " warhead " and caused detonation . The fuse length was determined by the amount of gunpowder in the paper tube , and was adjusted depending on the distance that the missile had to cover so that it would explode on the target . Its range was around 1 to 2 kilometers . The medium singijeon was of the same construction and function as the large singijeon , but , due to its smaller size of 13 cm , its range was limited to 150 meters . However , its explosive warhead was still powerful enough to make a 30 cm - deep crater in a patch of sand . The small singijeon was simply an arrow with a gunpowder pouch attached to it , and had no explosive capabilities . It was launched in multiples of 100 by a hwacha , and had a range of 100 meters . All gunpowder weapons including the singijeon used black powder .