Science Check: Metal Gear Solid 3 Snake Eater October 11, 2011

Sometimes, you’re forced to make some severe leaps of logic as to just how plausible a video game’s grounded reality can be.  Some things we’re willing to take for granted, like enemies will simply just carry health and ammunition supplies with them at all times, and you will be immediately able to make use of them.

But then sometimes there will be moments in gaming which skirt the bounds of reality and you are forced to ask yourself…COULD THAT REALLY HAPPEN?  Fortunately for me, I happen to have a bunch of friends on speed dial with science backgrounds and when I ask them questions, they have no problem filling me in on just what reality would do in these situations.

So this is Science Check, where I take a look at the leaps and bounds of scientific logic that games have made over the years and check if it would indeed work, or if you tried doing it in the real world, you’d be totally screwed.

This time, I’m talking about Metal Gear Solid 3, and if you’ve played the game you know if I’m talking about Metal Gear Solid 3, I’m probably going to be asking about the Shagohod.  You are correct.

For those of you who haven’t played Metal Gear Solid 3 and don’t know what the Shagohod is, please enjoy this scene from the game which goes into explicit detail about what it is, what it does, and how it works.

That’s right ladies and gentlemen, we’re going to be talking about a Rocket Tank.

Inter-Contentental Ballistic Missiles (ICBMs) are enormous rockets which carry a nuclear payload.  They are so massive that they have to be housed in missile silos, where they are buried deep underground on military owned unmarked land.  The locations of these silos are pretty well-known by the opposition, and they are supposedly monitored by spy satellites constantly.  During the Cold War, if one side was to launch their nuclear payloads, the deterrence was that the other side would know pretty quickly and launch their own missiles in retaliation, simultaneously destroying each other (and probably taking the rest of the planet with it).

Neither side liked this stalemate very much and each tried to do the best they could to gain an advantage over the other.  The most famous of which was when the Russians tried to install WMDs into Cuba, causing the Cuban Missile Crisis.  Other attempts to gain an advantage included when each side built nuclear equipped submarines, which were equipped with nuclear missiles of their own, capable of firing against their opponent, but these subs could be detected by sonar systems or the opposing country’s own submarines and turned away.

The Shagohod represents the extreme case of these conditions.  Obviously during nuclear war, you want to be able to launch anything against your enemy in secret .  To gain an advantage over the Americans, in Metal Gear Solid 3, the decision was made to build a nuclear equipped tank capable of firing from any point in Russia to hit anywhere in the mainland United States.  Since any ICBM capable of traveling that distance would require two stages (it needed to be big enough to contain all the fuel it would need for making that distance) a standard ICBM would be too big to fit on any tank.

The brilliance of the design of the Shagohod is that in order to make up for the lack of a second stage on the projectile it was equipped with two rocket engines that could bring it up to speeds of 300 MPH, which fired a payload while at top speed with the intention that by firing the rocket while at speed, the total possible distance of the launched missile would increase by three times, eliminating the need for a second stage on the missile thus allowing it to be small enough to fit on the tank.

The idea of firing a weapon in motion is an interesting concept that goes back as early as weapons themselves. In fact, earlier cultures would train to use a bow and arrow while on horseback.  The idea was that firing the bow while the horse was galloping at full speed would transfer some of that speed to the arrow while it was fired, giving the arrow the chance to penetrate the target further and increase the chance of a lethal hit.  Penetration, when it comes to a nuclear weapon, is completely useless.  A nuclear weapon does not explode on impact, it detonates in the atmosphere because its more effective that way.  The game specifically says this method was designed to increase the total distance of the missile and that is what we’re going to judge it by.

Unfortunately, in reality it doesn’t look like something like the Shagohod would ever be able to get off the ground.  The physics experts I’ve talked to have informed me that you can only transfer motion in that way if whatever is launching it has a much larger motion than the projectile its firing.  In this case you have a very large tank going at 300 miles per hour firing a projectile which has a much smaller mass but travels at a much faster velocity.  The problem is that the mass of whatever’s firing the projectile is meaningless, only the mass of the projectile and its velocity are what matters.

As you can see in the theoretical video, the Shagohod is firing its nuclear missile at an angle, which means it is not launching at the same exact direction that the tank is at.  After any projectile leaves its launcher, it will immediately start decreasing horizontal velocity and things like gravity will start to kick in and work against it.  Any initial speed it would have gotten from the launch boost would be lost in a matter of seconds.

The final nail in this coffin is the fact that rockets are designed to be fired from a standstill.  You don’t want high acceleration in a rocket as it would make things harder to change.  A high mass object going at high acceleration is difficult to control, and an uncontrollable weapon is not useful to a major government power.

It makes sense that something like the Shagohod was never actually made, because in reality it wouldn’t work.  On paper the concept is terrifying (and makes for a great video game threat) but in reality, the physics in place would not work as the game said it would.  I appreciate that the game did give specific numbers in order to make the threat the Shagohod possessed seem more immediate, but the laws of inertia are not on the Shagohod’s side.