Mining equipment, smelting equipment, power supply, vehicles, greenhouses, pipelines, pumps. Remember, this colony will need to mine its own metal supply, make its own buildings, including glass for greenhouses. If it makes its own greenhouses, pipelines, etc, it must have the equipment for doing so. In particular, it must have a sufficient supply of equipment and consumables to last until the self-sustaining mode begins. That could easily be decades.

While I grant that the availability of water on Mars, plus its tenuous atmosphere, make Mars vastly better than the Moon as a place to colonize, it is still pretty rough.

Check out what the annual requirements are for our bases in Antarctica. Of course, there is no mining or growing going on there.

The minimum for a sustainable colony would be truly huge. In my own estimate, it would take at least 1,000 tonnes of cargo brough to the surface of Mars to do the job, perhaps 10,000 tonnes.

David F Mayer