Future Robot Space Explorers, Technological Developments Options

[ljk4-1]

Robotic 'spiders' could be the key to building large-scale structures in space,
according to ESA's Advanced Concepts Team. The tiny mechanical spiders would
inch their way across large nets of fabric in space performing small tasks or
lining up to create an antenna or some other structure.

Full story:

http://www.esa.int/esaCP/SEMHVXVLWFE_index_0.html


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Exploring Caves with Hopping Microbots

Astrobiology Magazine Dec. 8, 2005
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NASA-funded researchers are
developing "hopping microbots"
capable of exploring hazardous
terrain, including underground caves
and one day, to search for life
below the surface of...

http://www.kurzweilai.net/email/newsRedire...sID=5103&m=7610

[dvandorn]

Hmmm... well, if you used a common transmission for all three flywheels, or if you can manage to add energy to all three of them in exactly the same increments at exactly the same time, then you're really operating as if you had three constant-speed CMGs, I would think.

-the other Doug

[helvick]

Hmmm... well, if you used a common transmission for all three flywheels, or if you can manage to add energy to all three of them in exactly the same increments at exactly the same time, then you're really operating as if you had three constant-speed CMGs, I would think.

That would just give you net rotation in the 3 axes. You need to be able to add energy into the system without adding any net angular momentum - the simplest way of doing that that I can think of is to have two contra rotating flywheels on each axis that are driven in such a way that energy inputs and outputs accelerate\decelerate contra-ratating pairs. In gyro pointing\rotation control mode they would be driven asymmetrically.

So the simple problem is managing the changing angular momentum imparted by storing or bleeding off energy, or at least figuring out what the net change is that needs to be managed. With two contra rotating flywheels on each axis it should be theoretically straightforward to add\bleed energy in response to changing charge\load conditions without imparting any net additional angular momentum to the main body. The hard problem that I see arises when attempting to manage the angular momentum transferred to and from the flywheels (acting as gyros) with the sort of precision that would be needed to manage the pointing of the craft. The hardest problem for me is figuring out how to add or remove energy from a contrarotating pair when they have been put in an asymmetric state.

Now it must be said that it's almost 20 years since I did any mecanical engineering work so I could be way off on this but my gut reaction is that a flywheel capable of storing a few hundred watts of power just can't be handled with that sort of delicacy. Also I never worked with any aerospace rated stuff and 20 years is a long time so maybe it is possible.