Nudging Asteroids

After doing my background research for Exploring Space on Potential a range of ideas came to mind on how an asteroid threatening life on Earth might be redirected to a safer orbit.  The ideas are in refinement but I thought I would put down outlines for right now.

Kicking Up Dust

One of the cool results of dust on the surface of an asteroid becoming electrically charged under sunlight, is that dust particles will accumulate in regions of shadow.  Impact craters will accumulate dusty deposits, similar to how dust stockpiles in the corners of your house (not quite in any real way but I think its a useful visual metaphor).  These large dust deposits might have potential as a "fuel" for a redirection system.  With the extremely low escape velocity found on asteroids, even ones large enough to cause a major environmental disasters hear on Earth, a small robotic system would be deployed on the surface of the target asteroid and spend its service life launching dust away from the asteroid and slowly change both the asteroid's mass and, at least minimally, the velocity of the asteroid as well.  The combined effect of losing mass and gentle application of force, over a long enough time scale, would ensure the asteroid would miss the orbital window necessary to impact on the Earth.

__Potential Means of Moving Dust

 ____Shakerbot in the craters:  The premise is relatively simple, a small robot or part of a larger robot           would wander the surface of the asteroid going from impact crater to impact crater and begin to violently shake, the energy transferred from this shaking action would cause some of the dust particulates to gain enough energy to be ejected from the asteroid.  Dust that wasn't ejected would still have the benefit of altering the rate at which sunlight was absorbed by the asteroids surface.

__________Swarm solution, many small shaker bots in craters, ruled over by a queen rover, who                                    would supply power for the shaker bots and transport the smaller robots as needed to                                  various sites of deployment

  _________Lonely bot, instead of having multiple robots the asteroid would have a single rover                                     transporting the shaker system from point to point

_________the Launcher:  this robot would be a more straight forward in design than the shaker bot,                                the design would emphasize a mechanical launcher that would scoop up dust and launch it                              into space.

_________Ablative propulsion, super heat the dust so that the vaporized material would provide a certain                     degree of thrust.  Impact craters might serve as convenient regions for material vaporization

                

________Ion Tether Drive:  By docking a conductive tether onto the surface of the asteroid it might be possible to use charge of the local dust to create a type of ion drive.  The tether would create a localized voltage gradient that dust particles could be attracted to, for this to work the pull of the tether would supply the local dust with enough additional energy to achieve escape velocity.  (this idea I have the most faith in)

Nuclear thrust Cap  Using a nuclear battery to redirect comets at extreme orbital distances into more convenient locations for future space mining.

Exploring Space on Potential

I recently read an article that proposed that ballooning spiders  propel themselves through the air by means of electrically charging silk extruded from their abdomen.  The author of the paper postulated that even a small amount of electrical charge would allow the spider to take advantage of the natural voltage gradient that occurs in the Earth's atmosphere, aiding in the spider's ability to travel tremendous distances.*  Reading this reminded me of an article I read about 6 years ago, within that article it was noted that as a result of solar wind, radiation, and the tail of the Earth's magnetic field, referred to as a plasma sheet, the surface of the Moon appears to create a natural voltage gradient.

I am curious, could the charged surface of the Moon be used in some way to power/propel micro space craft?  (Unfortunately this is one of my posts where I posit more questions than actual answers, although I find this idea too interesting to not at least spend an hour looking into)  While the voltage gradient of the Lunar surface may achieve relatively high voltages, the density of these charges may be insufficient to allow for non-microscopic space craft (although a microscopic space probe would be cool).

Imagine a swarm of small lunar explorers, the size and shape of small spiders spending their days wandering over the surface the Moon and other non-terrestrial surfaces.  Every month for six days when the moon is full in the Earth's night sky the little explorers will unwind statically charged tethers and ride the plasma eddies forever searching for critical materials to humanities exploration.

One potential application of such micro explorers could be to emphasize the discovery of deposits of regolith that contain high concentrations of critical elements like hydrogen and carbon.  By emphasizing narrowly defined sensors the robots within the swarm would hopefully be low enough cost that they could be dusted across the surface.  When a swarm encountered a deposit that it found to meet mission parameters, ex hydrogen ratios exceeding 22.5 parts per thousand (over 100x higher than background) the spiders would deactivate their tethers and wait to be noticed by overhead satellites (this is based on the assumption that a satellite's resolution might not be high enough to detect smaller deposits of resources, but could see the marker swarm in indicator mode).

Added 9/25/2013
Another potential means of utilizing this feature would be to create an extremely thin "magic carpet", the extremely massive surface area to mass would allow for as much charge as possible to support the structure.  An engineering concern for this approach would steam from the potential of the system to become tangled as a result of localized eddies in the motion of charge.  Either the structure could be made semi-rigid or small motors could be placed within the frame allowing for it to dynamically shape itself.

Regardless I hope that something like this happens as it would be wicked cool.
I feel I should say this somewhere, the rational behind a macroscopic swarm design generally stems from the additional mobility available during times where the voltage gradient is insufficient for propulsion.  It could make just as much sense, if not more so, to suggest developing microscopic swarm machines that used chemical switches to go from a roaming platform to detection marker.


*under ideal circumstances

Electrical Activity and Dust Lifting on Earth Mars and Beyond
An article that discusses various means by which dust can gain charge, including on bodies like the Moon and asteroids, it generally indicates that objects larger than 10 micrometers are unlikely to be lifted by the electrostatic force.  That being said the statements are for naturally occurring materials, not systems designed to drift along the gradient. (hey trying to be hopeful here)

Identification After Search and Rescue

A rather macabre idea that came to me a few days ago to potentially aid in more rapidly identifying human remains.  While dental records can help to positively identify a deceased individual the identification process, it is a tedious process.  One potential means of reducing the time required to identify a body, would be to implant materials in the gum line of patients creating a bar code like structure.  Such a bar code would allow forensic teams to reduce the potential number of dental registries that would need to be examined for final confirmation.  

There would be a range of social challenges of creating such implants and associated databases. Military organizations might consider it for their personnel. 

To avoid privacy concerns, no central database of the bar codes would need to be held, instead dentists could be issued a range of numbers that could be given to patients, and in the case of an unidentified body being found law enforcement could upload the all or part of the identification code and dental offices could supply the associated record(s) if they determined that one of their patients matched the identification code.

Channel Surfing on Streaming Services

One of the first world problems associated with the 21st century is the challenge of selecting what program to watch during an evening in.  Recommendation algorithms are aimed at highlighting a film or t.v. show that consumers might find appealing but they ignore a large underlying challenge for many users, the paradox of choice.  With dozens if not hundreds of options confronting users having the service provide a more streamlined interface could improve overall satisfaction.  When accessing an online service like Netflix or Hulu users would be presented with simple channel listings under defined categories, comedy, drama, action, etc.. upon selecting these channels a program within the category would appear.  Ideally the interface would follow the same methodology as Pandora where at the end of each selection users would be given the option to refine what kind of shows would appear next.  

Along similar lines users could also be provided the ability to create shared playlists of media available.  Now friends and family across the country can watch the same movie marathon.  Said playlists might also be stitched together to create full on channels.

Alternatively a media streaming service could create virtual channels where users could dynamically provide input as to what program would be selected next.