The ultimate goal of SpaceX is to have a permanent and sustainable city on Mars. This involves full independence of Earth in terms of necessities such as food, water, air and energy. The colony has to exist independently in the harsh conditions of Mars and provide the first multiplanetary colony of humankind.
This can only be attained through moving huge populations. SpaceX is aiming to fly waves of Starships with thousands, and later millions, of colonizers. This will require new levels of launch frequency, in-orbit refueling, and spacecraft optimized to be cost-effective to use and operate in large volume between planets.
Their long term goal is to convert Mars into an earth like planet through terraforming. This includes the wholesome change of the climate of Mars by increasing its atmosphere and heating it up, either by the emission of greenhouse gases or by the use of orbital mirrors. It is a long process that takes centuries.
The use of in-situ resources (ISRU) has to be mastered in the early stages of survival. The settlers will have to chisel water ice as fuel and life support, regolith mining, and create breathable air out of the atmosphere. Scalability is what cannot be negotiated on.
SpaceX is driven by these objectives at an extremely fast pace. With a course set on the first crewed missions of this decade and a sustainable city in 20-50 years, a rate much faster than conventional development in the aerospace industry becomes clear. The urgency is an essential part of their ambition.
Conclusion
The most characteristic Mars ambitions of SpaceX include creating an immortal, autonomic metropolis; shuttling giant populations on board the Starship floats; perfecting the use of Martian resources; and pushing the terraforming. These missions require magnitude and velocity that has never been seen before, and their primary objective is to turn humankind into a multiplanetary species.
