Mars Atmospheric Pressure affecting Ingenuity

Seasonal pressure variation on Mars

A very interesting update on the Mars 2020 mission appeared recently - specifically the Ingenuity helicopter's ability to fly in relationship to Mars' atmospheric pressure. The atmospheric density of Jezero crater is dropping. 

Seasonally, the atmospheric pressure on Mars varies approximates 25-30% peak-to-peak (Smith 2008) due to the exchange of CO2 with the polar ice cap. Ingenuity was designed for flights in atmospheric densities of 1.2-1.5% of Earth's. However, the density may drop to 1.0% requiring some extra spin-up of the blades to stop any aerodynamic stalling.

This does imply some considerations on how atmospheric variability might affect habitability when deeper exoplanet data is analyzed (Linsenmeier et al. 2015 have a good overview)

You can read more about the Ingenuity issues here.