Tesla CEO Elon Musk announced the significant addition of a titanium underbody shield for the Tesla Model S. According to the Elon Musk's Friday morning announcement at Medium.com, the new "triple underbody shield" is Tesla Motor's answer to the Model S fires in 2013 that caused a PR nightmare for the electric car company. Now, the new armor will be standard equipment on all Tesla vehicles beginning March 6 and will also be available to all existing Teslas free of charge. 

According to Musk, two Tesla Model S fires were the result of striking a foreign object at high speed, which punctured the battery pack located at the underbody of the Model S. Even though the likelihood of catastrophic strikes to the battery are rare, Musk is determined to bring the odds down to zero-- the ballistic grade armor plate is designed to withstand even the gnarliest of road debris.

"During the course of 152 vehicle level tests, the shields prevented any damage that could cause a fire or penetrate the existing quarter inch of ballistic grade aluminum armor plate that already protects the battery pack," described CEO Elon Musk. "We have tried every worst case debris impact we can think of, including hardened steel structures set in the ideal position for a piking event, essentially equivalent to driving a car at highway speed into a steel spear braced on the tarmac."

Why is the new armor for the Tesla Model S known as the "triple underbody shield?" That is because the robust safety device actually offers three layers of protection:

First, a hollow aluminum bar offers the first line of defense. The aluminum bar is designed to deflect an object entirely, or to at least send the object away from a trajectory towards the battery pack. If the Tesla is dealing with a denser object, then the debris may pierce through the plastic aeroshield after it is deflected by the aluminum bar. However, Tesla assures that the damage to the aeroshield will not affect the safety and driveability of the vehicle during and after the impact.

The second line of defense of the "triple underbody shield" is the titanium plate, a high-strength shield capable of withstanding the brunt of the impact. Titanium plates are better known for their service in aerospace and military applications.

Should the debris still pose a risk to the car, the third and final piece of the shield is a shallow angle solid aluminum extrosion that not only absorbs the last of the impact, but also deflects the object some more to allow a Tesla Model S essentially ramp over the immovable object.

“In this case, Tesla's revision of vehicle ride height and addition of increased underbody protection should reduce both the frequency of underbody strikes and the resultant fire risk," said the NHTSA's Office of Defects Investigation. "A defect trend has not been identified. Accordingly, the investigation is closed.”

Be sure to watch the GIFs below for a demonstration on the Tesla Model S "triple underbody shield" at work: