Development of the on-orbit maintenance and manipulation workbench (MMW) for the Chinese space station

The logistic supply for Space Station is very expensive and difficult compared with any other human natural exploration activities due to launch costs and challenges, and the logistic problems of establishing bases on the Moon and Mars in the future will be more prominent. Especially for emergencies, the losses caused by ground support delay will be immeasurable. Considering the successful maintenance of the Hubble Telescope and operations on the ISS, one of the most effective methods to solve the logistic supply problem is to enhance the capability of self-maintenance and support of the facilities. Through the participation of astronauts and a series of tools and technical support, the capability of self-maintenance and support of the facilities can be effectively improved. For this purpose, the on-orbit Maintenance and Manipulation Workbench (MMW) has been developed and installed on the Mengtian Lab Module (MLM) of the Chinese Space Station (CSS) to provide an enclosed working area for on-orbit fault diagnosis, maintenance, and manual or mechanical operations for the payload. This paper introduces the development and functions of the MMW on the MLM. In the limited rack space and limited resources, the MMW provides a 380-L work volume, 1000-W DC power with a versatile supply interface (100, 28, and 12 Vdc), 800-W cooling capability, video and data recording and real-time downlink capabilities, ground commanding capability, wastes (waste gases and waste particles) treatment capabilities. With these capabilities, the MMW is an ideal platform to support the operation and test verification of fine mechanical operations, structural and electronic assembly of scientific experiments and technical experiments in the cabin, and to support the development of space robots and telescience technology experiments. Areas of research that will benefit from investigations in the MMW include fluid physics, materials science, combustion science, onorbit maintenance and manipulation, and advanced life support technologies. The mechanical, electrical and thermal control subsystems are discussed separately. Special tests for the treatment of wastes have been carried out to verify the capabilities. The development of the MMW will surely enhance the space research in the forthcoming long-term activities of CSS.