The longetivity of a contrail is determined by the atmospheric conditions. In sufficiently dry air no contrail is formed as the water introduced by the combustion isn’t enough to raise the frost point to the ambient temperature. More humidity means that the contrail may form and even persist for a while without sublimating away (Cirrus homogenitus). If the air is even more humid, the contrail may even start to grow and change shape (turning into Cirrus homomutatus). This last case is what I suspect gets the foil hats most riled up about “chemtrails”.

https://cloudatlas.wmo.int/en/explanatory-remarks-and-special-clouds-cirrus.html