15 days of continuous darkness followed by 15 days of continuous sunlight is rather difficult to deal with operationally, biologically and mechanically. This ca

15 days of continuous darkness followed by 15 days of continuous sunlight is rather difficult to deal with operationally, biologically and mechanically. This causes lots of mechanical stresses. Also there's micrometeorites that you need to protect against in LEO or on the Moon. The temperature extremes on Mars are nowhere near what they are on the Moon or in LEO. In LEO further you have no gravity and no materials so the only going there is bringing whatever you want to do there with you. There's no resources that can be used. With no gravity also many things simply can't work. For example you can't run any pumps that pump liquids built in a normal manner. You can't rely on gravity to separate or settle liquids.