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2. The Moon's low gravity and lack of atmosphere mean that you have to carry extra propellant to land.

Lack of atmosphere I get, but how does low gravity require more propellant to land?

(edit: maybe you meant lack of atmosphere due to low gravity, and I got the other meaning contrary to your intent)

Sorry, my first thought was that it requires more delta-v to enter a lunar capture orbit since the gravity is weak, but I just double checked the delta-v roadmap and it's actually not that high.

However, it is a bit problematic that landing a rocket on the lunar surface can kick rocks around the planet (thanks to the low gravity), possibly into orbit or beyond (which could pelt other equipment). So you need to switch to an entirely different propulsion system for descent, which carries a payload penalty.

https://upload.wikimedia.org/wikipedia/commons/9/93/Solar_sy...

You have to use the engines to slow down rather than aerobraking in the atmosphere.

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