On the M47 Dragon anti-tank missile system, each missile round had a humidity indicator. Army missiles spend most of their lives in storage, waiting either to be used in war or training. They have a shelf life of roughly 10 years. After a while, moisture is sure to work its way in, and cause corrosion, and otherwise degrade the missile. And so, the humidity indicator. A simple little plastic window. As a part of the pre-fire check-list, the shooter was supposed to look at the paper strip indicator in the window, and ensure the missile was still within acceptable limits. The strip would show one of three colors, blue, white, or pink. Blue meant there was little or no moisture in the missile, and presumably, the round was servicable. White indicated some moisture, and pink indicated an unacceptable level of moisture.
As a mnemonic device, soldiers were taught the following:
Blue is true= the round is servicable.
White is tight= acceptable for emergency use
Pink stinks= round is unserviceable, and should be turned in to Ordnance.
But here’s the thing. Missiles are pretty damn expensive. The Army tries to come up with as many alternative training methods besides shooting missiles to train missile gunners. But eventually, some level of live fire training has to be done. So, if you’re going to shoot live missiles, why not shoot those missiles that have been on the shelf the longest.
I’ve done a couple of Dragon missile live fires. And every single round we drew to shoot had pink.
Most of them worked.
Oh, they all left the tube.
But when a wire breaks (on a wire guided missile) and the high explosive warhead equipped missile decides to travel vertically, rather than horizontally, there’s a few tense moments while you wait for the “boom”. Since, you’re standing right under where it decided to go vertical.