Chinese Journey to the Challenger Deep: The Development and First Phase of Sea Trial of an 11,000-m Rainbowfish ARV

The remoteness and isolation of hadal zone environments make this region of inner space a particularly fertile field for scientific inquiry. After the successful development of the 7,000-m class deep manned submersible Jiaolong, the Chinese government and scientists have recognized the necessity to develop deep submergence vehicles up to 11,000 m depth. In this paper, a unique Chinese journey to the Challenger Deep is described. The whole project is to construct a movable laboratory that includes a mothership, three full ocean depth landers, a hybrid autonomous and remotely operated vehicle (ARV), and a human occupied vehicle (HOV). A three-phase approach is adopted for this project. Phase I is the completion of 4,000-m class sea trials of the first lander and the ARV with a temporary ship. Phase II is the completion of 11,000-m sea trials of the three landers and the ARV with the newly built mothership. Phase III is the completion of 11,000-m sea trials of the HOV with the same permanent mothership. In order to overcome the funding issue, a multiple investment method was introduced in this project. The basic idea is that the funding for the ARV and three landers will be sought from university sources and local government, the funding for the mothership will be sought from private investors, and only the manned submersible will seek support from the central government. To the authors' knowledge, this may be the first attempt in China to carry out a project with private investment as a supplement to governmental funding. The project has progressed very well over the past 3 years and has proven that this funding strategy is working. In this paper, the progress of the whole project is briefly introduced, while the focus is on the description of the design details of the Rainbowfish ARV including the results of the first phase of sea trials. The ARV planned to perform its 11,000-m class sea trial at the end of 2016.