Marvel Studios

The fast and furious "Iron Man 3," opening in U.S. theaters Friday, is a superior comic book movie packed with dazzling effects and relentlessly thrilling action sequences. Director Shane Black (writer of "Lethal Weapon") and leading man Robert Downey, Jr., find the right mix of humor and heroics. What's more, the film has not one but two effective villains -- Guy Pierce as mad scientist Aldrich Killian and Ben Kingsley as criminal mastermind The Mandarin.

But the real star of the film is, as always, that endlessly intriguing piece of high-tech hardware -- the Iron Man suit. How much of Tony Stark's signature creation is science, and how much is fiction? We take a look at the iconic features of the Iron Man armor, and the real-world science behind them.

iron man, science vs. fiction

The new Iron Man follows events in "The Avengers," in which Iron Man flies into the upper atmosphere then, by way of dimensional portal, into deep space. As such, Stark's armor must function as a full-pressure space suit -- regulating oxygen, temperature and air pressure. Such environmental suits have been in development as early as the 1930s. Because Stark is in open space, the armor would also require shielding against ultraviolet and particle radiation. The Iron Man armor would be classified as a hard shell space suit, like the one pictured above, as opposed to the more familiar soft and hybrid suits of the U.S. space program.

In related news, researchers at Massachusetts Institute of Technology are working on a skin-tight space suit designed to be worn in inside a pressurized spaceship. The Gravity Loading Countermeasure Skinsuit (GLCS) is designed to put pressure on the bones in an approximation of Earth gravity.

Marvel Studios

Also housed in the suit gauntlets, Iron Man's Repulsor rays are concussive force beams that rest squarely on the fiction end of science fiction weaponry. The Marvel Comics Database wiki describes the Repulsor blast as a "high density muon beam … directed by magnets and focused by electrostatic lenses." The beam emitted from the suit's breastplate is a supercharged version of the gauntlet rays.

Muons are plenty real -- they're subatomic particles similar to electrons and neutrinos -- as are particle beams. The idea of the particle beam weapon (PBW) has been around since the 1950s and has also been considered as part of a ballistic missile defense system. But the energy required to generate such a beam has made the weapon so far impractical. (You can, however, purchase Repulsor Beam underwear. This seems relevant.)

Cyberdyne

The Iron Man armor also serves as a kind of super-advanced powered exoskeleton, granting Stark increased strength and endurance. Several exoskeleton systems are already in use or in development, with an eye toward military applications or for use in rescue scenarios. Companies including Raytheon and Lockheed Martin have active exoskeleton programs.

The Japanese company Cyberdyne, working with Tsukuba University, currently supplies more than 150 Japanese hospitals with the HAL (Hybrid Assistive Limb) suit, pictured above. The newest HAL 5 system is a full-body exoskeleton that uses skin sensors to monitor the user's nerve signals and amplify motion. The system was recently issued a safety certificate in advance of worldwide rollout.

National Air and Space Museum

Tony Stark pilots the Iron Man suit by way of rocket thrusters in the boot and gauntlets. In the films, the effects choreography suggests that Stark can steer in flight by adjusting the angle and thrust of the four individual boosters.

The jet pack is the closest thing real-world science to Iron Man's thrusters. Powered by compressed gases or turbojets, jet packs are worn on the back and can achieve low-altitude flights of short duration. The Bell Rocket Belt, pictured above, is one of the earliest operable jet packs, and is currently on display at the National Air and Space Museum in Washington, D.C.

Marvel Studios

One of the most appealing aspects of "Iron Man 3" -- and the film adaptations in general -- is that, while the scientific details might not actually make sense, they seem to make sense within the context of the story. The movie plays fair within the rules of its own premise. For instance, in the real world, it would be impossible to generate the energy required for the suit's repulsor rays and thrusters. But in the notional universe of the films, power is provided by Iron Man's arc reactor, that glowing gadget in Stark's chest.

The films follow the established comic book mythology by explaining away arc reactor as a kind of miniaturized and self-contained nuclear fusion reactor (as opposed to a fission reactor). Recent computer simulations suggest that self-sustaining nuclear fusion may indeed be possible as a future real-world energy source.

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"Iron Man 3" introduces at least one new technology to the Stark armor, although the details are sketchy indeed. Early in the film, Tony Stark is seen experimenting with a substance that he injects into his bloodstream, which then allows him to telepathically summon his armor to him across great distances. Each piece of armor has its own rocket system and latches onto Stark automatically after it flies across the room (or the country, as the case may be).

As a sci-fi conceit, the concept combines ideas of nanotechology, biotechnology and long-range wireless communications. Stark has also developed a system for remotely piloting Iron Man suits from the ground. The suits essentially become unmanned aerial vehicles (UAVs) or drones, a recurring concern in movies these days. In real-world news, just this month the FAA will begin allowing civilian agencies to fly UAVs weighing no more than 4.4 pounds in U.S. airspace.

Marvel Studios

"Iron Man 3" continues the series' inventive point-of-view camera shots, in which the audience can see through Iron Man's visor and head-mounted display (HMD). As Iron Man surveys a group of bad guys, the HMD identifies individuals and overplays targeting information by way of the augmented reality display.

HMD technology has been around for a long while in military and engineering applications. The hotly anticipated Google Glass wearable computer promises to bring the technology into the consumer realm.