Communication with CubeSats

The final frontier is becoming more open.  Humans have gone from two players in the space game in the 1960's to a world where universities and small groups can launch their own mini-satellites into orbit by piggybacking on the delivery of much larger satellites into orbit.   These mini-satellites are generally designed to meet the Cube-Sat design specification, where the shape of the satellite must be cube like and each component cube has an edge length of 10 cm.  The consistency of the dimensions of a Cub-Sat make it easier for companies to accommodate for a known shape and volume, this is the same rational behind flat-rate boxes and shipping containers, while you may not always need the full volume you have a very clear idea of how much space you are allowed and the delivery company knows how to mail boxes that size.

Like many design choices the dimensions of a Cube-Sat have their trade-offs, while Cube-Sats can be easily launched in relatively large numbers, the small volume limits the available space for communication equipment, the less space for communication hardware, generally speaking, the lower the maximum bandwidth of the satellite.  As Cube-Sats become a more common tool of scientific exploration there is always a desire for more data from these small boxes.  One potential solution being investigated at MIT is to re-purpose an old anti-aircraft gun mount as a platform for 6 meter diameter satellite dish that will be large enough to concentrate the signal from research satellites and effectively communicate.  The challenges of overhauling this system has led to the question, instead of using a single massive communication array to contact orbiting Cub-Sats, why can't researchers use dozens, if not hundreds, of smaller dishes to communicate?  

SETI, the search for extre terrestrial intelligence has already done something similar to listen to the stars in the hopes of finding signs of alien life.  Instead of  a single massive radio antennae like the Aricebo Observatory SETI aims to use 350 antennae to create the equivalent signal capturing ability as a 100 meter radio telescope.  I would like to propose something similar, but on a smaller scale.  Instead of a single 6 meter diameter dish, with an effective collecting area of roughly 30 meters, network roughly 100 tracking dishes with a diameter of 1 meter.  Achieving the same operational surface area with a much more granular control on the effective collecting area and more critically, greater flexibility on where the platform can be deployed.  Now instead of a single use dish design solution, amateurs and professionals around the world could build their own radio arrays capable of creating data links with research satellites.

Now for the caveats, and there are many, the first is technical, would the mini-dish solution actually make sense for both uplink and downlinks.  As a data down link I am reasonably certain that this array concept could work, if the SETI design works I don't see why a smaller diameter dish array for closer signals couldn't work.  As to uplinks that is more dubious, I don't know enough about the physics of radio communication to make any real comments beyond the fact that I like this idea.  The second limitation is legal, which is also a big one, assuming the physics works out, the international community would need to establish some part of the EM band that could be used by these mini-arrays without interfering with other established orbital infrastructure.  The third is economics, while I would generally suggest that this design be open-source regardless, the scope of the market is hard to judge.  While the intent of smaller dishes is intended to lower the barrier of entry, the number of separate moving components might actually not make financial sense.  While the cost of an individual dish would be less than that of a larger tracking system, cost to own and operate the system over time is a greater concern.  Hundreds of dishes with at least 2 moving parts and sensitive electronics would require quite the maintenance effort.   Hopefully a lower cost of installing less massive infrastructure would mitigate the overall cost, the lower installation cost and the potential for economies of scale might make a technology like this viable.

A Powerful Wallet

One of the challenges for smart phone users is limited battery life.  While there are external batteries available to allow for on the go phone charging, these external chargers have two flaws aesthetic and clutter.  An external battery system is difficult to make aesthetically pleasing.  Beyond the aesthetic consideration many consumers are left with the challenge of finding space for another device to keep track of.  Personally as a male consumer, who isn't interested in getting a men's purse and has been told that cargo pants are no longer acceptable attire, I would rather limit the number of things I bring with me for a night (please note that I am simply referring to my personal experience, I feel that both men and women would appreciate a new solution).
To solve the concern of sufficient battery life in a convenient package, I would like to propose the "Power Wallet"  The Power Wallet aims to be a smart wallet for modern consumer, shaped like a standard bi-fold wallet, it would users to recharge their smart phone via an inbuilt USB power connector, all while still serving as a traditional wallet.

 For the Power Wallet to make sense it must achieve these design parameters, the volume should not exceed that of a standard wallet, it should be able to contain an assortment of currency and credit cards, all wiring elements should be able to be stored conveniently, and the wallet should be robust enough to survive regular daily use.  Ideally the design would provide minimal interference with RFID/NFC based communication standards used in many card systems.  Additional features might include, solar panels on the back of the wallet, a mini-flashlight, e-ink display (for reasons), the ability for wireless charging, and outlet prongs for the internal DC adapter(this might be pushing things).

 
The hard science limit of the design is the energy density of battery technology, for Li-Ion batteries this  value currently ranges between 250 Wh/L to 730 Wh/L. If we assume a middle value of 500 Wh/L= 500mAh/cm^3  we can then start to estimate how large of a battery we can add into the wallet.  For reasons of safety I am also going to imagine that the battery requires 2 mm of some kind of external protection, before the material of the wallet is considered.


Credit Cards have the dimension of 53.98 mm x 85.6 mm x 0.76 mm 
Starting from these baselines and a quick test of simply placing my cellphone's battery in my wallet we can assume that the Smart Wallet's internal battery could have the external dimensions of 6.4cm x 9.4 cm x 0.6 cm, making the actual battery volume 6.0cm x 9.0cm x 0.2 cm or 10.8 cm^3 continuing with the energy density assumption of 500mAh/cm^3 we can estimate the ability to store up to 5400mAh of power, or enough to fully charge a smart phone one and a half times (there are some efficiency issues to consider).  

While these numbers do sound appealing they should be taken with a grain of salt, to the best of my knowledge Li-Ion battery manufacture doesn't generally allow for company's to order batteries to volume, most of the sub-elements of the battery, referred to as cells, are cylindrical in nature, consequently the actual storage capacity of the battery system will be less.  

April 17 2014 It turns out someone was already looking into this idea, here is an article on gizmag that highlights a credit card sized back up battery.

Keeping your input dynamic

Years ago while visiting my older brother in New York City I had the good fortune of being able to visit the WIRED magazine pop-up store in Manhattan where the years most expensive technology was put on prominent display.  One technology was the Optimus Maximus keyboard, a slick piece of hardware where each key had an embedded full color display, allowing the user to dynamically define the visual profile of the key as well as the function associated with it.  Visually speaking I was incredibly impressed, but my opinion rapidly changed when I actually used the keyboard, the buttons felt too soft to the touch, which for the trade off of input flexibility might have been acceptable, if the price wasn't so incredible.  Costing well over $1,400 per keyboard, the Optimus felt like it was meshing with a very narrow consumer base.  I started to wonder if it would make more sense to create a less flashy but still tremendously flexible E-Ink version of the technology.  Each key possessing a separately addressable display module, allowing users to dynamically update the characters associated with the program being run.

The idea of integrating e-ink with input surfaces continues to evolve, what follows are a few outlines of how device flexibility might be improved.

Contemporary laptop track-pads are incredibly limiting on how they allow users to interact with their computer.  The surface area of interaction is mechanically limited to whatever segment of the computer body was defined by the design team.  When a user is predominately using their laptop as a typing device it makes sense to limit the potential of accidentally moving your cursor, but in an era where people use their computers for more than word processing the interface should evolve with the people.

Imagine a computer where the entire hand rest surface area is covered in a high contrast E-Ink display.  During "normal" operations, this visually adaptive trackpad (or VAT for the remainder of this article*) would  highlights the traditional position of the trackpad and accepts input.  The magic would happen when users open other programs, for example a photo editing suite, new icons would appear, providing rapid access to commonly used features.  For users who might need more fluid control over the sensitivity of the cursor they could define their track pad to allow for higher sensitivity at the center of the input region and lower sensitivity at the periphery or vice versa for gamers.

With the VAT occupying so much of the laptop's real estate  the physical click would also need to be improved.  One option would be to place the entire display on a slight hinge and allow for any region to be mechanically compressed for clicking to occur.  Another alternative would be to eliminate the mechanical click and instead implement haptic feedback devices through out the frame, where the screen would vibrate when it acknowledges a click or some other gesture.

 Social net working could be made more flexible with users being provided with tools to allow them to create small update windows.  These windows could do more than provide a place for you to read tweets, or the other obvious alternative of simple daily update widgets, the display could serve as an art piece, where the pattern would evolve according to any number of custom inputs and artistic themes.  As the refresh rate of E-Ink is much lower than traditional LCDs the art should attempt to embrace the limitations of the format.

Similar concepts and technologies.  The Razer Switchblade interface.  The Switchblade is a 4 inch multi-touch screen that serves as a trackpad for the Razer Blade Pro laptop.
Pros:  Having the LCD screen allows for a far more dynamic display on the input surface.
Cons:  The LCD requires more energy and is limited to a static point on the body of the laptop.

*sorry for the terrible name I couldn't think of a good one 

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.