Mars is a suicide mission.
Mars may be achievable if you do it right.
The first step is to send nuclear powered tunneling robots there, to slowly and methodically excavate tunnels in rock that can be used as habitats. They don’t have to be fast. While doing so they insert reinforcing rods into the ceiling, like modern mines. After a section is completed, they spray the interior with sealant against microfissures.
Their ships would then be cannibalized to make pressure doors, ceiling, walls and flooring, all with integrated electrical wiring. When done, they do a gas pressure and heat retention check. Then their nuclear power is used to provide more than enough energy.
An important concept of this is that it is cumulative, that the more missions to Mars that are sent, the more developed the tunnel complex becomes.