AK20I means 80% nitric acid + 20% N2O4 + Iodine passivant
AK = Azotna Kislota = Nitric Acid in
NASA
Similar to AK20I
A/L - AutoLand
A/L - AirLock
A/L - Approach and Landing
AA - Astronomical Applications
AA - Adverse Action
AA - Antenna Assembly
AAA - Avionics Air Assembly
View all in NASA