Duna's Atmosphere in 1.x
Prior to 1.0, flying on Duna was a significant challenge. Back in those High And Far Off Days Of Gods And Heroes, Duna's atmosphere was very analogous to the cliché description of Mars' atmosphere: "too thin to ignore, too thin to be useful". Making anything fly at all was a challenge. Being able to control it was a bigger challenge. Being able to land safely was even worse. And then, having made something capable of all that, getting it from the ground on Kerbin to Duna was even harder
Duna's atmosphere has changed significantly from v0.90. Datum level pressure has not changed, but the rate of pressure drop with increasing altitude is much less. The game also now calculates density as a function of pressure, temperature, and molecular weight, unlike before when it was simply a function of pressure. At low altitudes the density of Duna air is less than pre-1.0; however, at high altitudes it is much greater. At the datum level, Duna air is about half as dense as before, at 3