Beyond the earth’s atmosphere, most exterior operations will be done using mechanical remotes. Machines can operate outside without worrying about radiation shielding, pressurized suits, or extreme variations in temperature. The main problem is how to control and guide them for non-routine operations. The simplest solution is to have a nearby human operator. Good remote-guidance and stereo-video interfaces will need to be developed, but only once: the same interface could be used for a variety of remotely-controlled machines working outside of satellites, vehicles, and on the Lunar surface. When signal-delay is not a problem, such as for simpler tasks that can be partially-automated (like digging), Earth-based operators can be used at lower cost.
Standard operator interface:
On the remote itself, this includes stereo video cameras and mechanical arms and hands, probably proportioned close to those of the human operator. Therefore the operator can wear stereo-video goggles, and ‘mirroring’ armatures on their arms and hands. Or perhaps a simpler interface can just use video-screens, keyboards and joysticks.
This is a small, very maneuverable remote with fine manipulator hands. It can be used for repair and general-purpose external work.
Since they are small enough to go through airlocks, crabs can be adjusted frequently and used for moving small items into and out of habitable environments. One problem is power-supply on a small machine. Depending on context this could be photovoltaic panels or fuel cells, but for local work it could also be plugged into an electric power cable — essentially an extension cord.
Crabs can also be used for public-relations by NASA. Several units can be donated to the United Nations to be used for demining in post-war zones.
This is a large, slab-shaped trusswork with wheels at the four corners, and rolling-pin shaped flywheels encaged within. The flywheels will be iron disks fitted onto an axle and locked together. Altogether, roller-slabs would mass many tons, most of it being the flywheels.
The Slab is ‘recharged’ by hooking up to an electric supply and spinning up the flywheels; I suppose it could also operate on an electric power cable, but the amount of current might be a problem. For simplicity, each wheel should be driven by a separate electric motor and the motors draw current from flywheel-driven generators.
I think this should be the basic platform on which both diggers and ore trucks are built. Ore trucks would include tilting hoppers, as dump trucks do. Diggers would include equipment which is also powered by the flywheels. The digging equipment could be designed as a modular attachment that can be added to any standard Slab.