Developing Extra-Vehicular Robotics (EVRs) that use different methods of locomotion and manipulation is one strategy for coping with the bigger, heavier payloads of future space science platforms and vehicles, especially those in orbit. NASA researchers are looking at arachnid modes of locomotion for such operations, such as its Spidernaut. A spider's eight legs give it a multipoint stance with as many as seven down during a step. This allows footholds that can be more easily supported and that spread climbing loads more evenly across a structure without imparting torques. Spidernaut could carry large payloads across delicate solar arrays or telescopes, with very little structural loading. Spidernaut is being constructed at about 1/4 of its estimated final size. A one-leg test bed was constructed to perfect leg kinematics and walking capabilities. Researchers then built a successor two-leg prototype to test software and onboard electronics. Combined with an additional wheeled support structure, the two-legged model used linear actuators in a 3-degrees-of-freedom design that supports 100 lbs. per leg pair. Before building the eight-legged version, Spidernaut's hip actuator packaging was reduced, and flex between the leg and connecting structure was eliminated. (Source: NASA)
I agree, Rob. Up to now, most of the humanoid robots were designed to alleviate the psychological discomfort of dealing with a machine (consider Marilyn Monrobot's stand-up comedy robot). In space, that's the least of concerns.
Rob, I think you're right about that. Humanoid robots are mostly designed to interact with humans or equipment built for humans. They're not particularly useful otherwise, and would be over-designed in many cases, or just not functional.
Rob, I think the primary motivation for robot anthropomorphism is advertising. If you're trying to get more funding for your project and the way you do that is by demonstrations to non-engineers, then you want to make it as visually compelling as possible. People easily identify with the human form. However, if you're trying to do real science, function has to come first.
Then again, symmetry forces a lot of design choices that just happen to be anthropomorphic, or, at least, naturally inspired. For example, if you have two robotic manipulators and a set of sensors to observe what the manipulators are doing, you'd naturally want to put the sensors in between them and on a mast that can point the sensors in the desired direction. It's not biologically inspired, it's just a logical configuration. And if encasing the sensors in a humanoid head sells the project without affecting funtionality, why not do it?
Ann, I understand that fifedoms exist in inducstry, and there's nothing wrong with healthy competition since it often generates multiple good ideas. There are brilliant minds in each NASA center, and I think we'd get better results if they colaborated more instead of sabotaging each other's work.
Ann, I'm not too surprised there are not many humanoid robots in space. I would think function trumps all other considerations in space. Thus the robots are going to resemble what is required for function.
Thanks for the history, SparkyWatt. I thought I remembered it was a cutback in fed funds, not a lack of will from NASA, that stopped further moon exploration. I agree with Warren, they could have been long-term stars with continued exploration. Cutting their funds short was a tragedy.
btwolfe, I've read a lot about Robonaut's design, and you're right, there's a lot available online about it. Just thought you might have some other interesting tidbits to share, but we understand if you can't. Your comments about NASA fifedoms sound a lot like other industries, as well.
There's plenty of online resources about Robonaut and related work on the NASA website and elsewhere, so I won't elaborate. If it's not redily aparent, Robonaut 2, Centaur, and Spidernaut are all from the same team of engineers.
As to other blogger's comments about why NASA has not been more of a leader in innovation, it's partially because there's a lot of fifedoms in the agency and some of them will not be content unless their group is the only one doing a certain of type of work. I've seen plenty of comments and behavior by NASA "bosses" that serves to exclude other divisions (e.g., JSC vs Ames vs JPL) to the detriment of the agency as a whole. When these groups are forced to work together, they only do so grudgingly. Most of the NASA people are truly interested in doing good work, but it only takes a few power-hungry people to spoil it for the rest.
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