Search and recovery operations for the failed H-II Rocket Flight No.8 engine were carried out in
1999 at the request of the National Space Development Agency of Japan (NASDA). The rocket was
launched in November 15, 1999 and the first stage engine stopped in 4 minutes. The engine fell in the
northwestern Pacific Ocean region at a water depth ofabout 3,000m. The predicted search area was limited
to 3.3km width and 26km length ofbox by orbital calculation ofthe NASDA. The size ofthe main engine
was about 3.4m in height, with a diameter about 1.8m.
The Japan Marine Science & Technology Center (JAMSTEC) employed the latest equipment for the
three search cruises and the following procedures： (1) wide area survey for the submarine topography
using multi-narrow-beam echo sounder (Seabeam 2112) which was equipped on R/V ”Kairei”, (2) narrow
area survey for the unique sonar contacts by side scan sonar on a 10,000m class ROV ”Kaiko” and the deep
tow sonar towed at a speed of0.5 knots and a swath width of 1,000m for each side, and (3) detailed visual
observation of the engine by the super-HARP camera (an ultra-sensitive color TV camera) or the 3CCD
TV camera which was equipped on the deep tow camera and a 3,000m class ROV ”Dolphin-3K”.
As a result, the JAMSTEC was able to locate the engine in approximately 5 weeks. Then, NASDA
employed an U.S. salvage company for recovery operation that was carried out by a 6,000m class ROV
”Remora6000”and succeeded in recovering the engine from the deep seafloor within only two months
after the launch.
The success of the mission demonstrated the high of level technical expertise and underwater
technology that JAMSTEC has cultivated over the last 30 years.
Wehave challenged to adopt several micro-electronic devices for marine biotelemetry. The devices
included data storage tags, ultrasonic tags and satellite platform transmitter terminals (PTTs). In this
paper, we introduced brand-new devices for marine biotelemetry including a magnetic field sensor
accelerometer tag (MR tag) and a visual data storage tag (CCD tag). We performed the first trials of the
proto-type ofthe brand-new tags attached to adult sea turtles in Thailand and discussed feasibilities ofthe
devices for biotelemetry.
Continuous record of ambient water temperature and depth was obtained for a free-ranging red sea
bream using a data logger in the natural sea for over 150 days. The fish (FL 43.0cm, BW 1.5kg) was
releasedon 1 December, 1997 at a point in Wakasa Bay (35° 35' N, 135° 29' E) and recovered on 5
May, 1998 at a pointwhere was 15km far from the releasing point(35° 44' N, 135° 26' E). Temperature
recordwasdividedintothree typicalpatternsin accordance withseasonal environmental change;decreasing
temperature period from early to mid winter, low and constant temperature period from mid February to
early April, and increasing temperature period from early to mid spring, respectively. Swimmingactivity
increased with rising water temperature in the increasing temperature period. The critical temperature for
activity to beginwas 12° C. This value wasequal to the lowerlimit of optimum temperature of red sea
breams whichwas determined by respiratory trials. Risingup to 12° Cambientwatertemperature seems
to switch the behaviour of red sea bream in the natural sea.