We were talking, for some odd reason, about keel-hauling.
In keeping with the tradition that we are actually now living in a Flying Castle, situated in the asteroid belt beyond Mars, the question was asked, "How do you keel-haul someone in space?"
(Sionnsar posted a review of the history of the Flying Castle back here, post 2326.)
I was answering that question.
Spider robots were designed prior to, and specifically for, our journey to the moon. We needed an efficient way to do work in low gravity and vacuum.
We needed something that could withstand the temperature extremes, and be robust enough for construction work.
They are large, filling the design space of a four-meter sphere with their eight arms/legs folded along their exterior surfaces.
The arms are fastened at the equator of the sphere, or beltline. This more or less circular ring can rotate if needed, and equipment storage bays are arranged above and below the beltline.
The first segment of the arm is one-fourth the circumference of the sphere. The second is one-half. All joints are freely rotating, and the arms can assume a wide variety of combinations in their orientations.
In the final segment, a manipulating and grasping appendage is affixed, corresponding to the wrist and hand of a human. I have decided to call these appendages “pedipalps”. This is a three-fingered hand modeled, as the name implies, after arachnid and insect manipulating devices.
The joint structure allows the pedipalp to reverse-bend the segments in order to “hook on” or to anchor its grasp inside a hollow space or handhold. The appendage can also be tightened into a fist-like appearance so that its hardened casing can act as a foot; hence the pedi- portion of the name.
When an operator is controlling the spider robot, fingers are paired together in the form of a Vulcan salute, and the thumb functions separately. A bit of training suffices to gain the rudiments of the system, and considerable dexterity can be achieved very quickly.
Controlling the robot was designed to be intuitive and natural.
As can be calculated, the outstretched arm/leg segments afford a very long reach, and can be used effectively in moving the robot across uneven terrain.
Most operators choose to use an insect gait, allocating a triangle of three legs to follow the motions of one human leg, and a corresponding and overlapping triangle from the other side will follow the motions of the other human leg. This feels very natural and allows fine control in adjusting a standing position or walking at a slow pace.
More advanced ambulatory techniques require an exceedingly skilled and coordinated operator.
The insect gait also permits two of the arm/leg devices to be used as arms, to carry material or equipment.
Thus it can be seen that even after only cursory instruction, the average individual will be able to operate a spider robot in a matter of minutes, and be doing useful work immediately.
Spider robots can be operated from a cabin and console interior to the robot, or from a similarly equipped remote location. Hand and foot motions can be replicated through telemetry, and force-feedback is a feature of both procedures. This means that a portion of the effort performed by the robot is fed back to the operator as resistance to further motion.
Of necessity, because of the nature of communications in outer space, it may be required to work through speed-of-light delays in controlling a robot. This requires patience, and the greater the distance, the more patience it requires. Operating a spider robot on the moon from a base on Earth is an extremely trying ordeal.
For this reason, we have designed computerized control systems that will allow us to pre-program actions to be undertaken at a distance. Those familiar with the actions of the Mars robots will appreciate the advantage of such techniques.
As much as possible, the computer systems on the spider robots are designed to be upgradeable, so that as better programs and procedures are made available, they can be downloaded into the onboard computers and sensor systems of the spider robots already in place. This is what we are doing with the spider robots we emplaced at our lunar outpost at the moon’s North Pole.