Search and recovery of the H-II Rocket Flight No. 8 engine

In November 1999, the H-II Rocket Flight No. 8 was launched from Tanegashima Space Center. However, the first stage engine stopped in 4 minutes. Consequently, the engine dropped 380 nautical miles off Izu-Ogasawara Islands in 3000 m of water. The JAMSTEC was requested to search for the first stage engine in order to identify the cause of the failure. The search area was a box, 3.3 km in width and 26 km in length. First of all, the survey using 40 kHz side scan sonar on board the ROV Kaiko was carried out. After seven days of sonar survey, a probable contact was obtained. It was the engine section. However, the main engine was not discovered yet. Then, the JAMSTEC/Deep Tow sonar was deployed in the second cruise. On the second day, sonar contacts were obtained approximately 15 km southeast of the engine section. On December 24, 1999, the main engine was discovered by the deep tow camera. In the third cruise, the nozzle skirt of the main engine was discovered by the ROV Dolphin-3K. Finally, the main engine was recovered approximately two months after the launch.