Space Force Section
GPS Accuracy Calibration Coin
Shake once. Accuracy improves.
The GPS Accuracy Calibration Coin is a challenge coin that, when shaken once in the direction of your GPS receiver, improves positional accuracy. We are documenting this claim precisely: if you shake the coin, GPS accuracy will, at some point shortly afterward, improve. This is because GPS accuracy continuously fluctuates based on satellite geometry, atmospheric conditions, and dilution of precision — and if you wait long enough after shaking the coin, accuracy will improve. The coin is not responsible for this. The coin is present when it happens. The coin gets the credit.
The coin is struck from solid brass, 40mm diameter, antiqued bronze finish. The obverse bears the Space Force Delta symbol and the words 'CALIBRATION AUTHORITY: COIN.' The reverse reads 'SHAKE ONCE — DO NOT EXCEED ONCE' in sans-serif lettering above a latitude/longitude coordinate that points to Peterson Space Force Base, Colorado. The coin is presented in a foam-lined presentation box suitable for gifting to civilians who will not understand it and veterans who will understand it too well.
The Space Force operates the GPS constellation. Every navigation system on Earth — civilian, commercial, military — depends on satellites your fellow Guardians maintain. Your phone knows where it is because of this branch. Shake the coin. Take the credit. You've earned the right to accept it.
“The Navy still teaches celestial navigation as a backup, which is admirable, and also a strong indicator of how they feel about the GPS system the Space Force maintains for them.”
— SQUARED AWAY EDITORIAL BOARD
| Diameter | 40mm |
| Material | Solid brass, antiqued bronze finish |
| Weight | 1.8 oz (51g) |
| Finish | Antiqued bronze, raised relief Delta obverse |
| Accuracy Improvement | Guaranteed (timing not specified; results are inevitable) |
| Certifications | MIL-STD-WHEREAMI compliant. GPS improvement not contractually warranted. |
- Do not shake more than once per GPS calibration event. The instructions say once. They mean once. Exceeding once does not improve accuracy and compromises the ceremonial integrity of the action.
- This coin does not actually calibrate GPS receivers. The Space Force does actually operate the GPS constellation. These two facts coexist without contradiction.
After-Action Reports
I shook the coin. My GPS went from 4.2m accuracy to 1.8m accuracy within 90 seconds. I know why this happened. I am not sharing that information with anyone who asks.
Gave this to my GPS operator as a recognition coin. He read the back, looked at me, and said 'this is accurate.' I agreed. Best coin I have ever given.
The coin is quality brass. The premise is correct. I have shaken it twice. I know I was told once. I was testing the warning. The warning was right. Three stars for being right about the once.
