NASA learned early on that the decompression problems of soft space suits could be avoided if hard-shelled full pressure suits were used. If a soft suit was full pressurized, the astronaut would be splayed out like a starfish and probably could not bend their arms or legs. A hard suit does not have that problem, but instead has the problem of wearing out the astronaut. They are about as easy to work in as a set of medieval plate armor constructed of pure osmium. So NASA looked into adding a powered exoskeleton to the suit, to reduce the muscle strain on the astronaut. NASA eventually decided it was not worth the effort, but the idea just wouldn't go away. Especially if the powered exoskeleton is attached to a suit of armor. It would be "powered armor".
And it took about five minutes for science fiction writers to figure out if you put weapons on on the armor you'd have an unstoppable one-man-army suit that would let a 99 pound weakling beat the snot out of Superman.
A baseline Powered-exoskeleton is a human shaped external skeleton constructed of strong materials, with powerful electronic servomotors or hydraulic actuators replacing human muscles. There are many variants.
I made up these definitions all by myself. If you don't like them, feel free to make up your own.
- OPERATOR (OPR:)
- Human Being [Human]
- Unintelligent software [Comp App]
- Artificial Intelligence [Comp AI]
- AMPLIFIER LOCATION (LOC:)
- Operator Inside Amplifier 
- Amplifier Inside Operator [-]
- Operator Remote Controlling Amplifier [+]
- CONTROLS (CTL)
- Human Controls
- Game Controller [Game]
- Exoskeleton Motion-Capture system [Exo-Mocap]
- Brain-Computer Interface [BCI]
- Computer Controls
- Digital Interface [DigInt] (computer just plugs into the man amplifier)
- Human Controls
- AMPLIFIER SIZE (SIZ)
- Smaller Than Human Sized 
- Human Sized 
- Slightly Larger Than Human Sized 
- Quite A Bit Larger Than Human Sized 
- Outrageously Larger Than Human Sized 
- COMBAT (COM)
- None [A0] No combat armor, but non-gun combat enhancements (load carrying, sensors, etc.)
- Partial [A½] Partial armor protection
- Full [A1] Total armor coverage
- Environment Suit [A2] Total Armor Coverage plus life support and CBRN defense
- Integral Weapons [W:1]
- or [NON] No combat armor, no combat enhancements, no integral weapons
The OPERATOR is the entity operating the man amplifier, either a person (OPR:Human) or a computer running either simplistic pre-programmed task software (i.e., a Roomba vacuum cleaner) or full-fledged AI software (i.e., Ultron).
If the operator is a computer (OPR:Comp), the man amplifier is classified as a Robot. If the computer is running unintelligent software (OPR:Comp App) it is a Robot Appliance). If the computer is running Artificial Intelligence software (OPR:Comp AI) it is a Robot Synthetic Organism)
The AMPLIFIER LOCATION is the location of the amplifier with respect to the Operator.
LOC:0 If the operator is inside the amplifier then it is an exoskeleton. Examples include Tony Stark wearing an Iron Man suit, Col. Quaritch driving an "AMP" suit, Raleigh and Mako in their Jaeger, or this is a self-contained Robot Appliance or Robot Synthetic Organism (Intel Inside)
LOC:- If the amplifier is surgically embedded inside the operator, then it is an endoskeleton and the amplifier is called a Cyborg. An example is the Six Million Dollar Man. This option does not make sense if the operator is a computer.
LOC:+ If the amplifier is remotely controlled at some distance from either the human or computer operator, then it is a Telerobotic Drone with only 3rd person visual feedback, such as an unmanned aerial vehicle or a waldo handling radioactive material. More extreme is a Telepresence Drone, with 1st person visual and haptic feedback in virtual reality.
The CONTROLS are how the operator issues commands to the man amplifier.
A Game Gontroller (CTL:Game) is a joystick and a keyboard set up, a steering wheel with brakes and accelerator, or other manually operated controls.
An exoskeleton motion capture system (CTL:Exo-Mocap) is something attached to various portions of the operator's body to measure body motions, such as waldo hands, power gloves, or even a full-body frame. Instead of the operator using manual controls for the man amplifier, the operator moves their body naturally and the exo-mocap ensures that the man amplifier mimics the motion. This allows the operator to focus on the task at hand instead of wasting time fighting with the joystick.
An exo-mocap for human form fitting man amplifiers sometimes use negative feedback. Exo-mocap for huge man amplifiers or remote controlled drones sometimes use haptic feedback. This means the operator is suspended inside the exoskeleton, and the exoskeleton is forced to conform to the current position of the remote drone. This allows the operator to do things like climb stairs and feel when the drone has walked into a brick wall. For example, in the movie Pacific Rim, when the pilots walk, their feet are not actually on any flat surface. Instead the exo-mocap bits attached to their feet stop the motion (and hovering in the air) when the giant mecha's foot hits the ground.
A Brain—computer interface (CTL:BCI) uses electronics to directly communicate with the human brain in order to issue commands to the man amplifier. The operator just thinks their commands to the man amplifier. Sometimes the man amplifier can communicate back, with sensory information (or with enslaving thought control). Also known as mind-machine interface (MMI), brain—machine interface (BMI), or direct neural interface.
In the movie Pacific Rim, the Humongous Mecha each have not one, but two pilots who do synchronised piloting. This seemed like a pretty stupid idea to me, until I read this report. Apparently with a BCI, a single pilot has an accuracy of 67%, but dual pilots have an accuracy of 90%. Reaction times are halved. And momentary lapses of attention are not quite as fatal, since the other pilot is hopefully still on the job. The technical term is "collaborative BCI".
Sometimes the man amplifier also has "computerized reflexes", to automatically react common situations, e.g., tripping over an obstacle or unexpectedly coming under sniper fire. So even if the operator does not react to sniper, the computer reflexes in the amplifier can do the reacting instead.
A Digital Inteface (CTL:DigInt) is for Computer Apps or Computer AIs to control the man amplifier. Basically it is the wires (or WiFi box) and ports used to plug in the computer.
The AMPLIFIER SIZE is a rough indication of the relative size. Smaller that Human Size (SIZ:0) would be some sort of remote drone. Human Sized (SIZ:1) would be something like Tony Stark's Iron Man armor. Slightly to Quite A Bit Larger Than Human Sized (SIZ:2 to 3) are called Mini-Mecha. An example is Tony Stark's Hulk-Buster armor from Avengers: Age of Ultron. And Outrageously Larger Than Human Size (SIZ:4) are called Houmongous Mecha. They are more like skyscrapers, an example are the Jaegers from Pacific Rim.
COMBAT is a rough indication of military or other combat modification.
Armor is protection against hostile weapons.
None (COM:A0) is an absence of combat armor, but there might be other combat-related non-weapon enhancements (e.g., the ability to carry an increased loadout of ammo and supplies, combat sensors, heightened runnings speed, etc). Partial (COM:A½) means that only some of the amplifier is covered with armor. Both of these are called Combat Exoskeletons.
Full (COM:A1) means the amplifier is totally covered with armor. Enviroment Suit (COM:A2) means not only does it have total armor, but also life support (i.e., it is a space suit) and CBRN defense as well. Both of these are called Powered Armor.
Integral weapons (COM:W1) mean some weapons that are built into the amplifier, instead of being separate firearms being carried. An example is the "laser finger" found in The Forever War, with the ultimate "point-and-shoot" interface.
COM:NON means amplifier has zero armor, zero combat enhancements, and zero weapons
If there exists an A rating, a W rating, or both, the word "Combat" is prefixed to the name. For instance, an amplifier with OPR:Comp and W:Yes would be a Combat Robot.
Man Amplifier: A more or less human sized powered-exoskeleton controlled by an internal exo-mocap with a human operator. In some cases the powered-exoskeleton and the exo-mocap are merged into a single unit. Generally the exo-mocap uses negative feadback. It is called a "man amplifier" because it literally amplifies the person's strength.
|CTL: Exo-mocap, BCI|
|COM: must have|
If COM:A1 or COM:A2, it is Powered Armor. Otherwise it is a Combat Exoskeleton.
For an in-depth analysis on combat exoskeletons, read this article at the always erudite Future War Stories.
For an in-depth analysis on powered armor, read this article at the always worth reading Future War Stories.
|CTL: any Human|
Mecha: A larger than human sized powered-exoskeleton controlled by a human operator in an internal control cabin (generally in the Mecha's head or chest) via a game controller, exo-mocap, or BCI. If controlled by exo-mocap, usually has haptic feedback. According to TV Tropes tank-sized mecha are "Mini Mecha" and mecha which are several stories tall are "Humongous Mecha". As they put it, if the operator can be described as a "pilot" or "driver", then you have a Mini Mecha on your hands.
If COM: is anything but NON, then it is a Combat Mecha.
Telerobotics aka "Drone" or "Remote": In this context, a man amplifier, powered armor, or mecha where the human operator is not inside the machine, but instead is located at some distance using remote control. Control is by either game controller, exo-mocap, or BCI. If controlled by exo-mocap it almost invariably has haptic feedback.
If COM: is anything but NON, then it is a Combat Drone.
|CTL: Exo-mocap, BCI|
Cyborg: In this context, a Man Amplifier that is surgically embedded inside the human operator's body. Sometimes also includes other enhancements, such as sensors, life support gear, replacement organs, armor and weapons. Aka "bionics", "six million dollar man".
If COM: is anything but NON, then it is a Combat Cyborg.
|OPR: Comp App, Comp AI|
Robot: A man amplifier, powered armor, or mecha where the operator is a computer.
OPR: Comp App are Robot Appliances, only capable of perform pre-programmed tasks and stealing jobs from automobile construction workers.
OPR: Comp AI are Robot Synthetic Organism; and are disturbing, Asimov's Four Laws of Robotics notwithstanding.
If COM: is anything but NON, then it is a Combat Robot.
There are several challenges standing in the way of creating a useful man amplifier. The primary difficulty is the power supply. The first Iron Man movie got that right, the most important invention of all was the "arc reactor", the miniature fusion reactor that supplies almost unlimited power. Real world man amplifiers use non-rechargeable primary cells, internal combustion engines, and electrochemical fuel cells. These can only power the amplifier for a few hours. For many applications the designers give up and tether the man amplifier to a huge power generator via a power cable.
The material used to construct the exoskeleton is a problem. Aluminum is inexpensive, lightweight, does not stress the motors, and easy to mold. But if the operator is holding an automobile over their head and the aluminum decides to fold up like an accordion (i.e., "fail catastrophically in a high-load condition), the operator will be left feeling quite flat. There are safer but more expensive options like titanium and molded carbon-fiber plates.
The joint actuators (motors) are a problem. Hydraulics have the power and the accuracy, but are heavy due to the fluid-filled hoses and actuator cylinders, and tend to leak hydraulic fluid everywhere. Pneumatics are lighter but since gas is springy the accuracy suffers. Electronic servomotors are a better choice. They are more efficient and power-dense.
Joints are a problem. Human hips and shoulders are ball and socket joints, it is almost impossible to match all the possible human movements with an exoskeleton using single-axis hinges. This limits the operator's flexibility. An exoskeleton with external ball and socket joints have a problem with the series of joints being forced into misalignment. Using a hollow spherical ball joint that encloses the human joint is a better solution, but requires telescoping plates. And the problem of joints in the arms and legs are trivial compared to the nightmare of duplicating the human spine.
Power control and modulation are a problem. The actuators have to not move too fast, over shoot, or otherwise lag behind the operators movement.
Detection of unsafe motions is a problem. You do not want the man amplifier moving in such a way that it breaks the operator's arm, or damages another part of the exoskeleton.
Pinching and joint fouling is a problem. You do not want any part of the exoskeleton's hinges savagely pinching the skin of the operator, nor do you want environmental dust and grit getting into the joints.
Yes, all you young whipper-snappers think that powered armor is the latest cool thing since the first Iron Man movie came out in 2008. Well, as it turns out, the concept goes a long ways back. Even Iron Man himself goes a ways back, he first appeared in a comic book called Tales of Suspense #39 in March 1963.
The concept of a powered fighting suit arguably dates back to E. E. "Doc" Smith's Children of the Lens (1947) with Kimball Kinnision's armored suit made of pure dureum a quarter of an inch thick. Doc Smith had armored suits back in 1937 with Galactic Patrol but those were not power-assisted. Later came Robert Heinlein's classic Starship Troopers (1959). In "Champion Robot" by E R James (1953), "Creakyfoot" is an eight foot high powered suit for use on farms and in factories. And before that, there were all sorts of bizarre patients for assisted walking/running machines powered by compressed air, wind-up springs, and steam.
Post 1960's powered armor will be covered in the subsequent sections.
Ordinary man-amplification takes the strength and moving ability of an average person and magnifies it. Prosthetics are for physically challenged people who strength or mobility is weaker than average, or even absent. The man-amplification is to amplify their abilitys up to that of an average person.
The prosthetics are generally limited to the arms and/or legs. If the prosthetics are for internal organs, this becomes more a medical cyborg. Naturally the division between the two types is sort of fuzzy.
The difference between an powered exoskeleton and a mecha is pretty straightforwards, but there is still a gray area. Exoskeletons are form-fitting and thus quite close to the size of the operator while mecha are typically huge with the operator inside a control cabin. Having said that, some mecha are controlled by the operator in the cabin wearing an exo-mocap that looks suspiciously like an exoskeleton with no armor (see the McCauley Walker below for an example). Powered exoskeletons are true "man amplifiers", they augment the operator's strength to do tasks. Mecha act more like an operator with a tractor or front-end loader. Mecha range in size from the size of a tank (Armored Trooper Votoms), to a few stories tall (Gundam), to the size of a skyscraper (Space Runaway Ideon), to the size of a city (Macross), or even larger.
The TV Tropes site calls mecha that are tank-sized or smaller "Mini Mecha" while those that are larger are called "Humongous Mecha." As they put it, if the operator can be described as a "pilot" or "driver", then you have a Mini Mecha on your hands. GURPS Mecha defines a "battlesuit" as powered armour where the pilot's arms and legs extend into the suit's arms and legs. A "mecha" is piloted from a cockpit.
John Reiher noted that the AMP suit from Avatar (pictured above) has a problem. The thing can't walk unless it can shift its center of gravity from one foot to another. If you play with the toy version of the mecha, you quickly discover that if it lifts a foot it will fall over. Its hips are too wide. This can be addressed with a some tricky engineering, but the design as pictured won't work.
Actually I learned about a possible solution back in 1966, which I was a little boy. The solution is probably older than I am.
I had a wind-up Snoopy walking toy. You wind up the spring and the toy walks. I noticed on the feet there were prongs. They looked unsightly to me, so I trimmed them off.
And when I wound it up, immediately with the first step the toy toppled over onto its side. There it lay sideways, with its feet sadly paddling the air. Obviously those prongs were crucial to keeping it upright.
By looking at the diagram of Snoopy above, you can deduce what happened to me. If the yellow cross leaves the green rectangle, it is topple time. When I foolishly trimmed the prongs from the feet, the green rectangle suddenly narrowed enough so the yellow cross was outside. If both feet were on the ground, the combined green rectangle confined the yellow cross. But the instance one foot was lifted, the green rectangle narrowed to the point where a topple was inevitable.
If you don't trim off the blasted prongs like an idiot, each foot's green rectangle is big enough to contain the yellow cross. This allows the toy to alternatively balance on one foot while moving the other foot ahead, thus making a walk cycle. Note that the tip of each prong must extend past the halfway point to the other side, since the yellow cross is at the halfway point between Snoopy's left side and right side.
Obviously my point is that early crude Mecha may have no choice but to have similar prongs on their feet.
Telerobotics in this context means remotely controlled drone. Ideally we would be talking about a humanoid drone controlled by a remote operator wearing an exo-mocap, but in the real world such drones are conspicuous by their absence.
Unlike robots, drones et al have no on-board brains or AI, they are remotely controlled by a human being. Waldoes are fixed in place, while robot arms like the amazing Canadarm can "walk" from socket to socket like a giant metal caterpillar.
And of course halfway between robots and crew are Cyborgs. Are you old enough to remember the word "bionic?" While it would be a big help to have crew members who do not need to breath or be protected from the temperature extremes of the space environment, there are those who question whether such people are really people at all. More to the point, an SF author has to decide if their readers would rather read about metal men or red-blooded fully human heroes. This is why cyborgs in SF are generally either the main character in a world of humans or a small population of peripheral bit players.
NASA is a little uncomfortable with the concept as well. Which is a pity, since a properly designed cyborg would be far superior space travelers compared to us pathetic humans. Implant internal oxygen tanks to remove the need for breathing, implant food tanks to remove the need for eating, and implant an electrode in the pleasure center of their brain to remove the scourge of boredom. You could really save on life support mass by using cyborgs.
The concept of a cyborg covers quite a broad range though. At one end of the spectrum it is quite common to find people who have intraocular lenses in their eyes due to cataract surgery. At the other end one almost never encounters a robot body controlled by a human brain floating in a tank.
In the role playing game Universe, people with enough money can have an "internal gravity web" surgically implanted. This is a series of strong nets anchored to bone that support the internal organs. It allows the person to undergo accelerations larger than 2.5g indefinitely with no ill effects.
In Anne McCaffrey's Brain & Brawn Ship series, The parents of babies with brilliant minds but severe physical disabilities can opt to have their child become a "shell person" instead of being euthanised. They are not quite just a brain in a tank, but the difference is academic. One of the ways a shell person pays off their training debt is by hiring out on a "brainship", basically becoming a cyborg with a starship for a body.
A man-amplifier for a disabled person's arms and legs are a standard prosthesis. But if the amplifier is to replace or support internal organs, this becomes more a medical cyborg. As previously mentioned there is no hard line between the two types.
In some science fiction, people are modified into cyborgs not for dull boring reasons like allowing spacecraft designers to scrimp on life-support. Cyborg implants can give people superhero-like powers. Especially combat powers, the military is always interested in creating super-soldiers.
In science fiction there is P.A.P.A. from Keith Laumer's A Plague of Demons, the Reega Modification from Michael Kring's The Space Mavericks, and the Body Modifications from Jack Vance's The Languages of Pao.
If the operator is actually a computer instead of a human being, you have a Robot. It would be so much more convenient to use an all robot crew. Robots do not require life support, and some types can be considered expendable. Unfortunately there is Burnside's Zeroth Law
About this time is where all commentators bring up Isaac Asimov's famous Four Laws of Robotics:
- A robot may not harm humanity, or, by inaction, allow humanity to come to harm.
- A robot may not injure a human being or, through inaction, allow a human being to come to harm, except where such orders would conflict with the Zeroth Law.
- A robot must obey the orders given it by human beings except where such orders would conflict with the Zeroth or First Law.
- A robot must protect its own existence as long as such protection does not conflict with the Zeroth, First, or Second Laws.
Such robots who are constrained by these laws are called Asenion robots (using a deliberately misspelled version of Asimov's name).
According to Asimov, in 1942 he was fed up with the robot stories from other authors that were all a re-hash of that stale old "Frankenstein" and "Faust" theme (often with a side order of "the robot as pathos"). He wanted to write about sympathetic robots, and formulated the laws to have the desired effect. He also invented the word "robotics" while he was at it.
Not that these laws would make a robot behave perfectly. Asimov milked the flaws for all they were worth, writing a large number of stories about how the laws could interfere with each other and create unintended consequences. The laws were embraced by so many other SF authors that some actually think they are laws of nature. TV Tropes has a huge section about this particular trope. In fact, the laws often appear in popular culture.
In reality it is not particularly a problem to create a robot lacking any or all of the laws. For instance, you'd want to leave out law 0 and law 1 if you were making a soldier robot, otherwise it would be sort of useless. And you can be certain that the Terminators do not have any of the laws at all.
Originally Asimov didn't include law 0, it was added later. It is also quite dangerous. It can lead directly into a "With Folded Hands" scenario (what TV Tropes called "The Computer Is Your Friend"). It can also allow a robot to ignore law 1 via Zeroth Law Rebellion. See also Second Law My Ass.
There are quite a few loopholes in the laws.
- A robot can only obey the laws within its knowledge. The novel The Naked Sun points out that an evil person can order a robot to add something to a victim's food, and the robot will unwittingly violate the first and second laws if the robot is unaware the additive is deadly poison. A robot will obey an order to fly a bomber spaceship to a planet and bomb the snot out of it, if the robot is unaware there are human beings living there.
- The four laws assume that the terms "human beings" and "robot" are understood and well defined. They ain't. In the novel Foundation and Earth, the planet Solaria has a large police force which has been programmed to identify only the Solarian race as "human". And then there is the can of worms represented by robots that look like humans (androids). A robot might be fooled into obeying orders given by an android.
- Nikola Kesarovski considered writing a science fiction story about a robot who did not obey any of the laws because it did not know it was a robot. It figured that if it was not a robot, the laws did not apply to it.
And of course all the loopholes highlighted in Asimov's positronic robot stories.
Hans P. Moravec of the Carnegie-Mellon University invented a unique robot design that he calls "Bush robots." One was featured in The Flight of the Dragonfly (AKA Rocheworld) written by Dr. Robert Forward (called the "Christmas Bush" because it is covered in millions of tiny red and green lasers). It can be described as a "fractal robot." Center pivot with six arms. Each arm subdivided into six smaller arms. This repeats quite a few times. The finest arms can reach into a piece of machinery through a tiny hole, fan out, and repair the inside of the machine. Arm segments can also detach for separate jobs. The entire assembly is controlled by the master computer.
You can read Dr. Moravec's NASA sponsored report here.
In the movie 2001, the arms of the pod have a similar fractal arrangement, each arm splitting into two, each of which further splits into two fingers.
An Android is a robot designed to look and act like a human. The first modern use of the term was in Jack Williamson's The Cometeers in 1936. Its first film appearance was in the 1927 movie Metropolis as Maschinenmensch, Maria's robot double.
A Humanoid Robot is a robot with all or part of it designed to resemble a human body, say to study bipedal locomotion. Robotnaut is a humanoid robot only designed to resemble the upper half of a human.
If the humanoid robot has all of it built to resemble a human for strictly aesthetic reasons, then it is technically an android. Typically these are easy to distinguish from real humans even if you cannot tell by sight: they sometimes look like animated medieval armor, cut them and they bleed machine oil, an x-ray will reveal a mess of gears and electronics, or something simple like that (this is called a Robotic Reveal). Humanoid-robot androids with perfect exteriors but imperfect AIs are only marginally more difficult to detect. They can only fool you as long as they are silent and stationary, otherwise you can tell that obviously something is wrong.
Synthetic organisms is a somewhat vague term. This covers both genetically engineering existing organisms and engineering surrogate organs from the ground up to perform the same function as an organic organ. If the result resembles a human for strictly aesthetic reason, then it is an android.
These types of android will be much more difficult to distinguish from a natural human being, unlike humanoid robots an x-ray cannot tell the difference. You will need a Voight-Kampff machine or something, and even then you will never quite be sure.
Current attempts at creating androids are running afoul of the Uncanny Valley. They are not close enough to be mistaken for a real human being, they are merely close enough to be unnervingly creepy.
In older science fiction the two common themes involving androids are:
- Androids seeking emancipation from slavery
- The confusion of real and ersatz (is that a human or is it an android? Sometimes the protagonist themselves are unsure if they are android or human)
Sometimes the robot is designed to look like an animal instead of a human.
In 1920 Karel Čapek's brother Josef invented the term "Robot", which were humanoid robots (from Czech word robota, meaning "servitude"). And for a couple of decades later in pulp science fiction robots looked like metal men because of course they did. It didn't occur to the writers that robots could be anything else. The technical term is skeuomorph.
It wasn't until later that the authors wondered if it would make more sense to have a robot design where form followed function. The most noteworthy examples were Anthony Boucher's short stories Q.U.R. and Robinc. Josef Čapek coined the word "robot", Isaac Asimov coined the word robotics, Norbert Wiener coined cybernetics, but Boucher coined "Usuform". It means a robot that is designed along functional lines, instead of stupidly forcing the design to look like a mental man.
In the real world, while fake robot mock-ups found in Worlds Faires and Disney displays were metal men, actual prototype robots made by real scientists were usuform from the start. The fake robots were little more than glorified Renaissance automata. Modern industrial robots are more sensible, often little more than an arm and a hand.
Current media science fiction is somewhat schizophrenic about it: with the Humanoid Robot C3PO and the Usuform R2D2 in the same movie. I guess C3PO gets a pass because it's function is Protocol Droid.