AK20 means 80% nitric acid + 20% N2O4
AK = Azotna Kislota = Nitric Acid in
NASA
Similar to AK20
0G - Zero Gravity
2GRLV - 2nd Generation Return to Launch Vehicle
2IC - Second In Command
2M - Micro Miniature
2MASS - Two Micron All-Sky Survey
2STO - Two Stage To Orbit
3-DOF - Three Degree Of Freedom
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