Thanks for an interesting comment. I wouldn't say that the website states specifically about 'all engineering problems' but more a 'salesy' statement (also sounded several times by NASA while explaining their Artemis mission - 'https://www.youtube.com/watch?v=_T8cn2J13-4&t=22s').
But like everything else, there is some truth to this that without a base on the Moon, the possibility of facing unpleasant surprises on Mars is even more. Additional to the experiments in 'Mars-like' places on the Earth, it would add more value by making similar experiences in outer space such as on the Moon.
Agree with you that Mars introduces technical challenges (like the atmospheric ones you mentioned) that are not specific to the Moon.
IMO, also the spacecraft aiming to travel to Mars (such as 'Starship') should prove their reliability to the distances that have already been traveled (like ISS, Moon) before sending them to unknown territories.
But like everything else, there is some truth to this that without a base on the Moon, the possibility of facing unpleasant surprises on Mars is even more. Additional to the experiments in 'Mars-like' places on the Earth, it would add more value by making similar experiences in outer space such as on the Moon.
Agree with you that Mars introduces technical challenges (like the atmospheric ones you mentioned) that are not specific to the Moon.
IMO, also the spacecraft aiming to travel to Mars (such as 'Starship') should prove their reliability to the distances that have already been traveled (like ISS, Moon) before sending them to unknown territories.