Q:

What was NASA's Tire Assault Vehicle? 

Why did NASA build a vehicle specifically designed to attack aircraft tires? 

A:

By the early 1990s the Space Shuttle Program had experienced some close calls with the landing and braking system, especially the tires.   Hard data was desired about the response of the tires to various off-nominal situations. 
To obtain this data, a surplus Convair 990 jetliner was converted into the Landing Systems Research Aircraft by adding an instrumented version of a Shuttle Orbiter landing gear into its midbody. 

Various tests were run, some resulting in destruction of the tire, others only resulting in damage. 

For the cases where the test tire was only damaged, it was judged dangerous to approach lest it explode.  A means was needed to safely deflate the tire remotely.  This was the genesis of the Tire Assault Vehicle (TAV). 
A radio-controlled model of a Tiger tank was acquired and modified by adding a DeWalt battery-powered drill, some metal armor, and a video camera.   The vehicle would be used to approach the damaged tire and deflate it by drilling a hole into the sidewall. 

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