is a rocket fuel (a storeable oxidiser): red fuming nitric acid
+ 13% N2
and 3% H2
O. The colour of the resulting red fuming nitric acid is imparted by N2
Usually used with an inhibitor (various sometimes secret substances - then revered as IRFNA) because HNO3
attacks most container materials.
More at: http://www.astronautix.com/props/nitidjpx.htm