re: Landing on Mars and on the Moon
To land on the Moon, you'd need a powered descent.
It's some amount of fuel, granted, but it's just that way.
Landing on Mars will require:
Aerobraking
A heat shield for atmospheric entry.
Parachutes to slow down more.
A few rockets being ignited for a few seconds.
Airbags.
That's a lot!
(If no airbags, then a longer duration rocket burn).
Raoul