Proposed Viable Mars Colonization

About 12 years ago I researched the relevant available information and data, and developed a Proposal to build a viable self-sufficient colony on Mars using current technology. Because of the advancements in technology, that Proposal is even more achievable today. We have the technology, all we need is the astronomical amount of funding required..

This plan is predicated upon several conditions:
All initial missions to Mars will be one way.
The colony is intended to be permanent.
The colony is designed to become viably self-sufficient.
Viability depends upon a sufficient number of initial colonists, perhaps 250 minimum.
Sufficient supplies sent initially to support all colonists for at least 10 years.

Step one is to use current, or more advanced orbital satellites, to determine the most suitable sites for permanent colonies. That could be in conjunction with data from current rovers on Mars.

Step two is to send at least one large rover to Mars to scout a designated site for a colony. The rover should be at least as big as a large SUV capable of relatively high speed autonomous travel, and capable of taking 10 meter core samples and analyzing them. Two or three such rovers is preferable. I will call these rovers Calypso. Calypso will have other uses as you will see. Using information from the orbiters, land the rovers in the most promising areas.

Construct robotic cargo vessels that can be sent to Mars ahead of time. They can be sent via the economy route, the most efficient Hohmann Transfer Orbits. The cargo vessels can filled with supplies sufficient to supply the colonists for 10 years. Additionally, the cargo vessels will transport the materials, equipment, seeds, and all other supplies to build and develop the ability to produce oxygen, water, food, and other necessities. Each craft can also be prefitted with basic plumbing, electrical wiring, LED lighting, various fittings, air locks, and hardware so the empty vessels can be used as habitats. The cargo vessels can be sent well ahead of the colonists to the chosen site. Without passengers, they can be subjected to higher acceleration, will not require artificial gravity, and withstand harder landing. Without living quarters and life support, they can be less expensive to build, carry more cargo, and less expensive to send to Mars. All other necessary equipment can be sent the same way. Without passengers, robotic supply vessels could also be used to test landing spacecraft on Mars because no lives would be in danger, and even crashed vessels could be used or salvaged.

I propose that the main propulsion section can be separated in orbit, and crash landed further from the site to provide more salvageable materials. That will reduce the energy required to land the remaining cargo section. Alternately the propulsion sections can be medium soft landed to save more parts intact.

Then send in the first 250 colonists. All these missions will be one way, maximizing the amount of cargo and people they can carry. The 250 colonists will cover every possible area of expertise, and all will be cross trained in at least two other areas, with additional general training.
For the voyage from Earth to Mars, I suggest building spacecraft providing variable artificial gravity. That would allow passengers to slowly acclimatize from 1G to .38G over the ~8 month voyage. In to In order to provide the decreasing gravitational environment, cylindrical craft that can be spun at different RPM could be used. However, to reduce the Coriolis Effect, they would have to be large in diameter. More practical would be a central spacecraft employing self contained habitat modules on tethers. Once underway, the tethers could be extended out to provide 1G, then slowly reeled in to .38 G during the duration of the trip.

When the colonists arrive, they can remove cargo containers from the vessels and store the supplies in inflated tents to protect from Martian fines. The now empty hulls can be used as habitats on the surface. They can be interconnected with or without airlocks between them. That would eliminate the need to send dedicated habitats to Mars. The cargo containers themselves can be designed to be disassembled, and the parts used to make tables, cabinets, beds, and other furniture for the habitats. The prefitted plumbing and electrical will make habitat conversion much easier.

For more protection, the colony can be built by moving the cargo vessel/habitats into nearby ravines and interconnecting them. If no ravines are available, trenches can be dug into the surface using the Calypso Rovers. Calypso Rovers can be used to cover the habitats with sufficient regolith to shield inhabitants from radiation, protection from meteorites, and insulation from cold.

Another, but more expensive option is to send a NTB (nuclear tunnel boring machine) and bore into rocky hillsides or the walls of natural canyons. We might even get lucky and find networks of natural caves.

Olympus Mons will possibly have thousands of miles of lava tubes that would make excellent habitats for large colonies. Olympus Mons would also have other advantages. It is near the equator and therefore have relatively temperate climate. At 22 km (13.6 mi or 72,000 ft) both landing and takeoff from the top would require less fuel than most other areas. Also, that would be an excellent place to have a MagLev rail launch assist system.

Additional colonies can be built in a similar manner nearby, but far enough away so that a large meteor strike on one colony will not affect the others.
I began this project over 12 years ago when discussions regarding establishing colonies on Mars inevitably resulted in "We don't have the technology to do that". I began looking into the relevant technology and what was being done with that technology at that time. Basically, the technology that was being applied to produce spacecraft in those days could be applied to scaled up versions or modifications of those spacecraft. The Atlas and Delta rocket delivered Rovers to Mars. Delivering unmanned Cargo rockets would be easy. Of course, now the guidance and control systems are capable of a great deal more precision, making landing spacecraft on Mars safer and easier.
I welcome suggestions, observations, and constructive criticism. I respectfully request that all comments be limited to the topic of this thread, which is:
The technical, physical, and physiological challenges of missions from Earth to Mars with the purpose of establishing a viable self-sufficient settlement as soon as possible.