The Special Purpose Dexterous Manipulator (SPDM) is an extremely advanced, highly dexterous dual-armed robot with a body that includes two shoulder structures that provide support for the arms. Each arm has seven joints, terminating with an Orbit Replacement Unit/Tool Changeout Mechanism (OTCM), the mechanism through which the SPDM arm interfaces with payloads and tools. The SPDM is also equipped with lights, video equipment, a tool platform and four tool holders. This two-armed robot will be able to touch and feel much like a human. It can sense various forces and moments on the payload and in response, can automatically compensate to ensure the payload is moved smoothly. 

The SPDM's primary role will be to carry out delicate maintenance and servicing tasks on the International Space Station. Tasks include installing and removing small payloads such as batteries, power supplies and computers; operate robotic tools such as specialized wrenches and socket extensions for delicate maintenance and servicing tasks; provide power and data connectivity to payloads; manipulate, install, remove and inspect scientific payloads. The SPDM will be controlled by the ISS crew via the Robotic Workstation and perform a great many of the tasks that would otherwise require an astronaut to perform on spacewalks. 

The SPDM will normally sit on the Mobile Base System and Canadarm2 will manipulate a payload to within the range of the SPDM for repair, maintenance or upgrade. Alternatively, the SPDM can be grappled by the free end of the Canadarm2 and maneuvered into position next to the payload for assembly requiring its delicate touch.

Technical Details

Width	0.88m
Length	3.5m
Mass (approx)	1,662Kg
Mass Handling Capacity	600Kg
Degrees of Freedom	15
Peak Power	2000 Watts
Average Power	600 Watts
Stopping Distance (under max. load)	0.15m

The SPDM is scheduled for launch on Space Station flight UF-4.