It could be something very low-tech even. Just a machine that turns solar-energy + some mechanical power into say mars-dust bricks, non-stop for use in future missions? Maybe something that just keeps digging a perpetually deeper and deeper trench in a straight line so that subsequent missions don't need big drills to find out below-surface samples?
But thinking about it now, I can't envision that we here would be able to come up with something sublime/novel that a huge army of really-smart people haven't already after spending decades thinking about it. Then again, we have a lot of smart people concentrated in this forum, so who knows if a weird/silly conversation triggered by IT-minded people, acts as a catalyst for the engineer-lurkers that see it.
All of those things need to be launched from earth, that is still expensive. Then transported to Mars, expensive. Then landed on Mars, expensive.
And then you land your digger, at a cost of at least a couple 100 million, and you have a dumb robot that digs a small hole?
We should do industrial build up, but for me that starts with solving cheap transportation from earth to Mars first. Then you can hope to bring things like nuclear reactors, that can actually produce the power you need significant work.
Currently we are going for science reason and very few people are even working on going with humans or industrialisation.
But thinking about it now, I can't envision that we here would be able to come up with something sublime/novel that a huge army of really-smart people haven't already after spending decades thinking about it. Then again, we have a lot of smart people concentrated in this forum, so who knows if a weird/silly conversation triggered by IT-minded people, acts as a catalyst for the engineer-lurkers that see it.