A vast number of engineering problems would need to be solved before these can be attempted. We also need to know much more than we currently do about Martian conditions.
What we know
Mars is a cold, rocky ball with a very thin atmosphere that’s just 1 per cent as dense as that of Earth. Atmospheric pressure at the surface is as low as the pressure 35 km up in Earth’s sky (Everest is 8.8 km high). There’s almost no free oxygen.
The gravity is about 38 per cent that of Earth. There’s water ice at the poles and underground, but no free surface water as far as we know. There’s plenty of seismic action with Marsquakes all the time. The day is 24 hours, 37 minutes long — almost the same. Although the planet is much smaller, the land area is as much, or more than Earth, since it has no oceans.
The sunlight is weaker. Charging solar panels takes longer. There’s no magnetic field to speak of. The lack of atmosphere and the very weak magnetic field means no protection against harsher solar radiation, which is blocked on Earth.
We don’t know if human beings can survive for extended periods under such conditions. Even if they can, the chances of them going insane due to isolation cannot be ruled out. Nor do we know if plants can be grown on the surface of this arid planet, inside hi-tech greenhouses. A Martian mission would mean a round trip of at least 12 months, with at least a 20-month-long wait on Mars, before a return trip can be launched. All in all, that’s at least 32 long months.
So why would humans go there?
Apart from scientific curiosity, which is a good reason in itself, Earth has endured multiple mass extinctions caused by events like meteorites strikes. Also, recall that there are more than enough nuclear weapons spread around to kill everyone many times over.
There is no credible defence against big meteor strikes, and no guarantee there won’t be a terrible nuclear conflict sometime. If there’s a colony on Mars, it may store DNA information in “libraries” to hedge against mass extinction events on Earth.
Any manned mission will need more powerful propulsion systems; good heat shields (to prevent humans being boiled); better spacesuits with systems to extract oxygen from atmospheric carbon dioxide; transport for moving around on the surface; reliable power supply (probably using miniature nuclear reactors); and laser communications. There will need to be viable habitats where humans can live on the surface indefinitely.
In addition, there will be the need to grow food, and recycle waste. Experiments in growing food on the International Space Station indicate it may be possible to grow food on Mars despite low gravity, weak sunlight and high radiation.
Experiments involving launching fungus into the stratosphere also indicate that black mould (which is a poisonous fungus) can survive in Martian atmosphere.
The UAE’s Hope is looking to provide a more complete picture of the atmosphere, by studying daily and seasonal changes. The Chinese Mission will look for underground water and any signs of life. Nasa will do mineral assaying, measure temperature, wind speeds, relative humidity, atmospheric dust, etc. It will crack Co2 to produce oxygen and do extended soil analysis and look for organic compounds. The robotic Ingenuity helicopter will do test flights as a technology demonstration.
It may seem crazy to tackle challenges of this order. None of these will be easy to solve. A raft-load of different technologies will have to be developed at the same time. Even failures will probably lead to spin-offs with terrestrial applications.
If humanity is ever going to cut the umbilical cord linking us to Earth, Mars has to be the first planetary destination.