Exploring the mysterious ocean and deep sea has long been a distant dream towards traditional continental countries. However, under the State High-Tech Development Plan, or “Program 863”, the manned deep-diving submersible, the Jiaolong had brought this dream into reality. If the success of 1000-meter test dive is considered as the splendid “prelude” of the story, the 3000-meter and 5000-meter scales could be the remarkable “development”, and 7000-meter scale would be definitely exciting “climax”. This summer, this Jiaolong will romantically perform this legend set against the vast background of the Mariana Trench in the Pacific.

Ye Cong, design director of Jiaolong has been interviewed on details of China’s submersible.

Time, Seas and Times

Time is undetermined to go to sea. However, regarding the meteorological factors in the target water, this test dive will be conducted in the Mariana Trench, the exclusive economic zone of Micronesia in the Pacific. According to the relevant information and field surveys, the condition of this water meets the requirements of the test dive in terms of the depth, state and the bottom situation.

There are many dives throughout the whole process. They were decided by the three phases of the test dive. First, the initial dives are to confirm the local seawater indicator parameters obtained by other means. The submersible can be adjusted by these dives to be fully adapted to deep diving environment. Second, the following dives aim to exam and test design technology indicators of the target depth. The third phase is to do undersea operations.

Retrieval, Insulation and Battery

Overall, Jiaolong did well in the previous test dives, however, there were also some problems existing. For instance, in last year’s 5000-meter test dive, it encountered a storm. If positioning and retrieving took any longer time, it would be a disaster. As a result, Jiaolong was installed a GPS.

Insulation problems happen most. During one of the dives of the 5000-meter test dive, circuit insulation testing alarmed. Fortunately, the task was completed; however, it could not cover the insulation problem fundamentally. Experts are trying their best to solve the insulation problems. Till now, they have found several clues to fix them.

The problem of battery’s abnormal heating was exposed in early time. The silver-zinc battery used in Jiaolong has the characteristic of high energy density. On account that the charge and discharge take few times, battery’s performance will degrade accompanied by the phenomenon of heating, gas generation and even soft battery tank rupture. Therefore, Jiaolong has been assembled with a set of standby battery. At the mean time, the performance of the battery is monitored constantly to make sure it works well.

Sampling, Research and Launching

For the purpose of this test dive, seabed sediment sampling, biological storage basket and water samples sampler have been prepared in case.　

Like last year’s test dive, the 7000-meter trial has the same objective of testing performance indicators at this depth. Large-scale scientific applications will be put into use officially for the condition that the performance meets the design requirements after these test dives. During the 5000-meter test dive, Jiaolong placed a logo of China Ocean Association and a wood carving Chinese dragon. Will the 7000-meter task do the same homework at the seabed? The answer is positive.

This year’s test dive will be conducted in other country’s exclusive economic zone. According to the international custom, if anything needs to be placed in the other country’s seabed, their official approval should be obtained. Since it is just a test dive, permanent markers will not be left there. Nevertheless, to mark that the submersible has been to this sea area, some markers will be taken there to have pictures taken which will be brought back with submersible. As for the specific marker, it is confidential now. However, it is affirmed that Chinese will create the manned deep-sea research new record with its own unique way of greeting the mysterious Pacific underwater world.