With HAPs you can simulate the air pressure and density conditions on Mars by elevating the training outpost to 100,000 feet. Martian Gravity can also be simulated by descending at a constante rate. According to AI: To simulate Martian gravity, the HAPs must have a rate of descent rate of -1,201ft/min(-6.1m/s).
This gives us about 30minutes of both a gravitational as well as a atmospheric environment closely matching Mars. From 100,000 ft to 67,000ft. Or 30km to 20km.
https://drive.google.com/file/d/1Mw7tz1juCmEHFIO164HMi4ZPISM3ySbG/view?usp=drive_link
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