Micronautics?  Maybe you have heard this word before, but as I typed it in my word processor the spell-checker highlighted it right away.  So it is not in the dictionary yet.  It will be there one day.  How soon this will happen?  I guess it depends on our techno progress, but I am sure: we need it.  Micronautics was a subject of science fiction for a long time.  In one short story, which I vaguely remember from my childhood, a guy has befriended a microscopic robot, which lived inside his body.  The robot cleaned guy’s veins and entertained him with some shrewd talks, until one day the host almost choked to death on a clam.  The robot saved him by pushing the clam out of his throat, but was sadly lost in a spit.  One has to be pretty small for “being lost in a spit”.  In fact, comparing to a real vehicle, say, eighteen-wheeler, measured in meters, nano-vehicle will have same dimensions measured in microns, i.e. it will be million times smaller on linear scales.  When building such extremely small machine will be possible, the best area of application will be indeed the inner micro-space of a human body.  Hence, when micronautics, i.e. an ability to navigate in microspace will become a reality, humanity will gain enormous benefits.  First of all, micronautics will bring revolutionary changes to medicine.  Our bodies could be literally cleaned and mended from inside.  Hundreds of maladies from infectious deceases to atherosclerosis will be obliterated or reduced to subject of regular cleanings, like professional teeth cleaning today.  Just “swallow your doctor”, as once Richard Feynman, great physicist, formulated the plot.  Feynman was actually quoting his graduate student, Al Hibbs, who came out with this idea (R. Feynman, There’s a Plenty of Room on the Bottom, 1959).  Of course, there is much more room than we can touch in this brief note.  One day such micro-robots will establish connection with our brains, and swallowing your doctor, tax accountant, Spanish teacher or parole officer will become a common practice.  Perhaps, our innermost freedom of will itself will need a constitutional protection one day.  However, before we will get into a need for a new amendment, a lot of technical problems must be solved.  It took a century to develop such sophisticated aeronautics, as one that we have today.  How much time do we have before the frontier of micronautics could be taken over as well as airspace?  Perhaps, considering acceleration of technological progress, we will get to that point within a shorter period of time.  One of the “simplest” tasks will be design of an engine for nano-robots.  The problem is that one cannot just scale down any existing mechanical engine, because comparing to our macroscopic world, material properties and dominating physical processes at micron scales will be different.  An engine of nano-vehicle must have very few moving parts, comparing to our vehicles.  How one can make such a thing?  Beamed-energy propulsion (BEP) is a right way for moving nano-vehicles.  Majority of BEP applications are designed for space.  The principle of the process is relatively simple: energy is beamed to the spacecraft from a separate and often remote source.  In real life this likely will be a space-borne high-power laser.  In order to get “beamed”, the spacecraft collects and focuses the incident laser beam on some solid propellant.  Under high focus, propellant instantaneously vaporizes into energetic, often ionized exhaust, which propels the vehicle by rocket principle.  This is one of possible BEP scenarios, called ablative laser propulsion.  There are other schemes, but when we are switching from “the space” to micro-space, the main question is: who would voluntarily agree to rocket launches inside his (her) veins and arteries?  Good news is that at nano-scales we dont even need to employ any destructive propulsion techniques.  The medium of micronautics is mostly water, which composes 90% of blood plasma.  In order to move in a liquid, many bacteria are using so-called flagellum, a tail of a helical shape, which essentially works as a propeller.  Similar idea can be employed in nano-engines.  The energy can be supplied from electromagnetic field: our bodies are practically transparent to magnetic fields, and to certain frequency ranges of electric field.  Thus, a nano-circuit in form of a loop or solenoid, which can rotate or wiggle under external electromagnetic field can do the job.  Flagellum will be attached to a circuit, or it might be just a natural continuation of it.  The orientation of a field will set a direction of motion.  It is worth noting that 50 years ago Richard Feynman predicted that nano-doctors will be moved by electrical motors driven with an external EM field.  There are other possibilities though, like x-ray beams, proposed by professors of Tokyo Tech University, Shiho and Yabe.  Micronautics may still sound like sci-fi, but it is now a subject of physics and engineering.  Among scientific meetings, where micronautics is discussed is International Symposium on Beamed Energy Propulsion (ISBEP).  The Sixth ISBEP will be held in Scottsdale, Arizona in November 2009.  Although the main scope of the conference will be application of BEP for space propulsion, some works on moving to micro-space are expected and will be very welcome there.