“Tony Stark was able to build this in a cave! With a box of scraps!”
The Iron Man suit is one of the most iconic symbols of the Marvel Cinematic Universe, ranking alongside Captain America’s shield and Thor’s Mjolnir. It would be fair to say that without the success of Iron Man, there would be no MCU.
What makes Iron Man so fascinating is that, unlike other superheroes in the MCU, Tony Stark (Robert Downey Jnr) had to engineer his success – literally. Stark was not born with supernatural abilities like Thor (Chris Hemsworth), or injected with a super-soldier serum, like Steve Rogers (Chris Evans). Instead, Stark relies on his engineering ingenuity to succeed. And Tony is most definitely an engineer.
“You can take away my house, all my tricks and toys, but one thing you can’t take away – I am Iron Man.”
The first Iron Man (2008) has a more realistic portrayal of technology than the later films. The suit-up scene in Iron Man takes a long time, as one would expect for a full-body exoskeleton. Whilst we can synthesize new elements (Einsteinium was created in 1952), any synthesized elements are incredibly dense and, unlike in Iron Man 2 (2010), would be unusable near humans due to being radioactive. Also, nanotechnology is not able to magically regrow itself, as portrayed in later films.

What we saw in the first film was aligned with reality, of sorts, but the later movies were most definitely not as Iron Man’s director, Jon Favreau, explained in an interview:
“After the first film, a number of tech companies talked about how uncanny a lot of our depictions of technology had turned out to be, and how many different films and videogames ended up being inspired by the imagery we used. This forced us to go a bit further into the future, and try and change the nature of this technology. If we’d just duplicated what happened in the first one, we would be behind the curve. So now we’re dealing with holograms, the interface within the suit, and the suit being upgraded too.”
Flight: Making a Super Sonic Man Outta You
“Yeah, I can fly”
Flight has been a perpetual dream for humanity. This is why the future has been portrayed with jet packs, hover cars, and rocket boots from pretty much the second we nailed the airplane. Hence, one of the first technologies that Tony Stark creates is flight functionality for Mark II of the Iron Man suit.
The Iron Man suit flies using thrust generated from the feet, with inertial guidance from the gloves. This essentially allows the wearer to achieve supersonic flight and keep pace with F-22 Raptor jet fighters.
Whilst flying suits may seem fanciful, we do already have this technology, such as the Gravity Jet Suit, with which the Royal Navy recently conducted successful boarding exercises.
The Gravity Jet Suit is powered by five micro gas turbines, which use four liters of fuel per minute to generate 1000bhp. Rather than flying like a rocket, the jet suit essentially floats the user to where they want to be, with the core uplift generated from one turbine on the wearer’s back, plus two on each arm for stability and maneuverability.
In Iron Man, take-offs and landings are, generally, fairly realistic. With the feet and hand thrusters pointed downwards, uplift is generated in a similar fashion to the Gravity Jet Suit. It is when the Iron Man suit is flying horizontally – superhero style – that the science starts to break down.
In forward flight, when thrust is only generated from behind, the Iron Man suit essentially acts like a rocket or a plane, except it doesn’t have any wings (to generate lift) or fins (for stability), and is about as aerodynamic as, well, a billionaire wrapped in steel. There is also no attempt to provide uplift, which would at least allow the suit to maintain altitude. In reality, when flown like that, the Iron Man suit would fly straight into the ground, headfirst.

Rapid deceleration, such as when Iron Man deploys flaps to evade the F-22s, is also a problem. This is why planes come to a gradual stop on a runway. Sudden changes can place incredible strain upon the human body, leading to tunnel vision and unconsciousness, whether the person is protected inside a vehicle or not. This is why astronauts and pilots are trained to withstand G-forces.
There is also an issue with Iron Man’s superhero landings, such as the suitably dramatic moment during the Ten Rings attack of Gulmira in Iron Man … Whilst superhero landings look amazing, they would also play havoc with the body (see: Deadpool 2).
“Superhero landing! You know, that’s really hard on your knees. Totally impractical; they all do it.”
Strength: Buns of Steel
“The suit and I are one.”
The Iron Man suit is sufficiently strong to lift cars and punch through concrete walls.
The mass of an average-sized car is around 1,500kg (approximately 3,360 lbs), hence we can estimate how powerful the Iron Man suit is. Since force is equal to the mass of an object multiplied by acceleration, using acceleration due to gravity of 9.81m/s² gives us 1500 x 9.81, which is nearly 15kN. This is similar to the lifting capacity of the small dockside cranes used for unloading fishing vessels.
One of the problems with carrying heavier loads is that we not only have to be strong enough to move the object, but our musculature also needs to be sufficiently resilient to withstand that weight. It is for this reason that back problems are common injuries.

Despite powered exoskeletons seeming like pure science fiction, the military has been developing exoskeletons that will allow soldiers to carry more weight for longer periods of time. Prototype exoskeletons are being developed to assist warehouse workers carrying heavy loads, such as the suits being trialed at Delta Airlines, which allow the wearer to lift up to 14st. (nearly 90kg) for up to eight hours. Meanwhile, prosthetic suits are also being developed to give people with disabilities a greater degree of mobility.
The Iron Man suit acts as a powered exoskeleton, by amplifying the wearer’s strength and reinforcing their structure, allowing the wearer to not only lift a far heavier object but withstand the stress of carrying that weight. By having the Iron Man suit act as an all-encompassing suit, it essentially becomes a full-body prosthesis, allowing the wearer of the suit to be fully supported whilst lifting incredible loads with ease.
Impact Protection: Rolling with the Punches
“Iron Man. That’s kind of catchy. I mean it’s not technically accurate.”
The Iron Man suit is seemingly impervious to conventional weaponry, up to and including tank shells and 20mm rounds from the M61A2 Vulcan rotary cannon on an F-22 Raptor… barring some slight blemishes to the paintwork.
This protection is apparently afforded by the titanium-gold alloy it is made from. Whilst it is true that we already have armored vehicles and bullet-proof vests, they are often bulky items. For example, the armor at the front of a battle tank is over 30cm of steel. Likewise, the armor worn by bomb disposal teams is incredibly cumbersome and typically weighs 80lbs (36kg), which is about the same as a ten-year-old child.
That said, titanium-gold is a genuine alloy, with higher yield strength, tensile strength, and hardness than either of its constituent metals. Researchers also discovered in 2016 that the intermetallic titanium-gold alloy, known as β-Ti3Au is nearly four times harder than titanium.

Unfortunately, gold is also an incredibly dense material, making it much heavier than even lead. This makes it impractical for flight, as materials have to be as light as possible for minimising the overall weight. The heavier an object, the more difficult and inefficient it is to fly. This, amongst other reasons, is why modern jet fighters (such as the aforementioned F-22 Raptor), rely not on armor for their defense but on maneuverability, radar jamming, and ever more sophisticated sensors.
A titanium-gold alloy could afford a reasonable level of impact protection against low-mass objects, such as shrapnel. However, the Iron Man suit is portrayed as saving the wearer when they are slammed into hard surfaces, such as when Stark is shot out of the sky by a tank shell and falls to the ground. These types of impact are different. Instead of something small hitting the Iron Man suit, it is the suit that is hitting something much bigger (the ground). In these instances, as well as having to negate the energy from the impact it also has to deal with the sudden deceleration.
In reality, this close-fitting suit would do little to protect the wearer from this sort of impact. When the wearer is slammed into concrete, it is the instant deceleration that causes most of the injury.
In instances where the Iron Man suit falls so hard that it leaves a crater, in all likelihood the wearer would suffer major internal bleeding and their spine would be shattered. Thick padding or gas-cushioning would help with minimizing impact injuries, but there does not appear to be space for this.
Artificial Intelligence: Okay, Computer
Tony: Okay, let’s see what this thing can do. What’s SR-71’s record?
J.A.R.V.I.S.: The altitude record for fixed wing flight is 85,000 feet, sir.
Tony: Records are made to be broken!
Whilst the Iron Man suit is not sentient, it does have an onboard artificial intelligence (A.I.) called J.A.R.V.I.S. (Just A Rather Very Intelligent System). J.A.R.V.I.S. provides assistance to Stark in response to voice commands, such as deploying flares.
This is not unlike virtual assistants such as Alexa and Siri. However, virtual assistants are still in their infancy and can only handle simple commands, such as “Play Avengers,” or “Set alarm for one hour.” They are at the present time insufficiently developed to respond to complex commands.
There is also the issue of the amount of background noise that would interfere with the system interpreting the commands. Just as James Rhodes complains about the background noise when he is calling Stark, who is in mid-flight, so too would the AI struggle to understand what was being asked in such circumstances.
However, AI and virtual assistants are becoming ever more powerful, with their range of capabilities increasing each year. AIs can now beat humans at strategy games like Go and write scripts for plays and television (with varying degrees of success). Whilst we are unlikely to see killer robots, AI is becoming ever more advanced and its capabilities are continually expanding.

There’s an argument to be made that an A.I. would be more effective instead of a human operator. The Pentagon’s Defense Advanced Research Projects Agency (DARPA) is already running simulations with AI-controlled fighters, using machine learning to feel out the most effective possible maneuvers in air combat and swarming enemy targets with. a level of coordination that would be impossible to human pilots. Here, Tony is ahead of the curve with J.A.R.V.I.S. co-ordinating a wave of vacant Iron Man suits at the climax of Iron Man 3.
Repulsors: Ronald Ray Gun
“They say that the best weapon is the one that you never have to fire. I respectfully disagree! I prefer the weapon you only have to fire once. That’s how dad did it, that’s how America does it, and it’s worked out pretty well so far.”
One of the most iconic elements of the Iron Man suit is the repulsor technology, which allows the suit to fly and fire energy blasts. This is where things get a little wonky, as it is never adequately explained in the MCU what type of energy projection this repulsor technology is.

According to Newton’s third law of motion, whenever two objects interact, they exert equal and opposite forces on each other. A prime example of this is when a bullet is fired, which results in recoil from the gun.
At some times Iron Man’s repulsors have an equal and opposite reaction, such as when the suit is flying or when Stark’s arm recoils after the energy blast when he is only wearing the glove of the Iron Man suit. However, there are times when it seems that repulsors are essentially reactionless forces (which would break the laws of physics). It could be argued that the Iron Man suit allows the wearer to be braced against the kickback, but that is not always possible (such as when flying).
Also, energy weapons do not cause shock waves capable of flinging people away. Instead, energy weapons, such as the AN/SEQ-3 laser weapon system, fire laser beams at enemy vehicles to fry sensors, burn out motors, and detonate explosive materials. In some ways, these effects mimic the beam fired from Iron Man’s chest piece, as seen when Stark is destroying the Jericho missiles at the Ten Rings base. The scale and intensity of the beam are far greater than the energy weapon systems in use today.
Arc Reactor: Clash of Generations
Yinsen: That doesn’t look like the Jericho missile.
Tony: That’s because it is a miniaturized arc reactor. I’ve got a big one powering my factory at home.
Yinsen: What will it generate?
Tony: If my math is right – and it always is – three gigajoules per second.
Yinsen: That could run your heart for 50 lifetimes!
Tony: Yeah… or something big for fifteen minutes.
The Iron Man suit is powered by a circular device called a miniaturized Arc reactor, first designed as a replacement for the car battery that powered an electromagnet that stopped metal shrapnel from piercing his heart.
Stark explains to Yinsen that his Arc reactor can generate 3 GJ/s. To put that into perspective; a single large nuclear reactor produces 1 GJ/s (1000 MWe). No explanation is given as to how such a large generating capacity could be fitted into a chest-mounted device.
Stark’s use of palladium is interesting, as that implies the Arc reactor could be a cold fusion reactor. Cold fusion is a controversial field that caused a lot of excitement in scientific circles in 1989 after papers explaining the theory and results were published in a peer-reviewed journal. However, subsequent experiments failed to replicate the reported results and other indicators of fusion (by-products) were not found. The original researchers, although adamant that they had observed excess energy in their palladium cells, eventually admitted their experiment had not resulted in cold fusion.

The mention of palladium could be a red herring. The shape of the full-sized Arc reactor at Stark headquarters later in the film appears to be similar in design to the Joint European Torus (JET) reactor at the Culham Centre for Fusion Energy. This implies that the Arc reactor could be some form of a magnetic hot fusion reactor.
Fusion power is a relatively clean form of nuclear power: rather than splitting the nuclei of heavy atoms (as in nuclear fission), it compresses and then fuses lighter atoms, which does not result in long-lived nuclear waste. However, fusion reactors do emit radiation when operating and remain radioactive for a short while after, albeit nowhere near the extent of fission reactors. Stark’s Arc reactor would therefore require shielding to protect him from radiation, which is tricky when the reactor is next to his heart. Tritium, a vital part of fusion energy, is a low-energy beta emitter, which is a radiation hazard if inhaled or absorbed through the skin, which could be a problem if next to the wearer’s body.
Fusion power has been demonstrated and extensively studied. It is now an engineering challenge to make it commercially viable (getting more energy out than you put in). The UK government recently announced plans for a fully working fusion reactor in twenty years’ time (although this has been a repeated statement by many others for over 50 years).
The problem with this method of power generation is that a magnetic hot fusion reactor is huge, roughly the size of a house, and surrounded by enough equipment to fill an aircraft hangar. Miniaturizing something of that size down to a 15cm sphere, whilst still maintaining a useful level of power output, would be impossible with any technologies that are currently known.
Most of today’s exoskeletons are either powered directly from the mains, limiting their range to the length of their power lead, or by battery, which would require frequent recharging.
French inventor Franky Zapata recently completed a 22-mile channel crossing on his jet-powered flyboard in 22 minutes. Although Zapata was able to achieve speeds of up to 100mph, he still needed to refuel by switching to another backpack after ten minutes.
The efficiency of the Arc reactor also needs to be considered. 100 percent efficiency is impossible, due to the second law of thermodynamics (entropy – the amount of disorder in a system – always increases, hence whenever energy changes from one form to another there is always a loss). Modern nuclear power plants operate at about 40 per cent efficiency. Even if the Arc reactor were to operate at an unattainable 99 percent efficiency, 1 percent of the output would be in the form of heat. Just 1 percent leakage would result in 30MW of thermal energy being expelled from Stark’s chest. After a fraction of a second of operation, Stark would probably explode into a cloud of steam.
All in One: Mech of all Trades
The problems of how feasible an Iron Man suit would be are apparent when we combine all these technologies into a single unit. Miniaturization only goes so far. Whilst it is true that we have powered exoskeletons, toughened materials, flying suits, laser weaponry, and A.I.s, we have not yet combined them all into a single unit.
The more systems that are incorporated into a single unit, the more complex it becomes, which increases the number of potential points of failure. Essentially, the more components there are in a system, the greater the risk that one of them will break down and cause the entire system to fail. This can be mitigated by having redundancies in place (such as backup systems), but this increases the size of the whole system.
There is also the issue that power generation and power storage technologies lag behind other advances. For example; as smartphones have become more powerful, battery technology has not kept pace. An old Nokia 8210 could go for days without charging, but the latest smartphone can barely last 24 hours.
So, is the Iron Man suit possible?
Some form of flying suit, similar to the Iron Man suit could be possible, just without a miniature Arc reactor. We already have some of the technologies in use today (flying suits and strength augmentation). Although repulsors are pure fantasy, there are energy weapon systems mounted on naval warships. Of course, the films exaggerate some of the suit’s functions for the purpose of dramatic storytelling, but the core idea of an Iron Man suit is not without merit… as long as you have no ambitions of flying alongside jet fighters.
That said, Selfridges are now selling Gravity Jet Suits, so you never know just what the future holds…
This article was first published on October 29th, 2021, on the original Companion website.
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