A manned mission to mars should be our first objective. Mars is the most earth-like planet in our solar system, and the easiest one to terraform. A terraformed mars would become a home for humanity, a green world that is filled with life, and a biological refuge for earth's life in case the earth becomes uninhabitable. The spectacular Martian scenery would make mars a premier tourist destination. The great distance between mars and earth would force us to develop the advanced technology necessary to go to mars and colonize it. The same technology would also be used to colonize the rest of the solar system. 

The crew on the first manned mission to mars would build a permanent base on the surface of mars, and build or place a space station in orbit around mars as backup. The base on the surface would be a habitat, science laboratory, and centre for Martian exploration. The space station would be a command centre, habitat, supply depot, rest and relaxation centre, and emergency shelter. The space station would also carry an ion drive that would enable it to travel as a space ship between mars and earth. 

We should use the ISS (International Space Station) to go to mars. It could be converted into a spaceship in one or two years. The ISS already contains a habitable environment for long term space voyages; a crew; docking facilities for resupply vehicles and mars landers; and lots of room to transport crew members, mars landers, and the necessary supplies, equipment and buildings for living on the surface of mars and the ISS. Ion drives and fuel modules could be attached to the ISS to convert it into a mars spaceship. The ion drives' constant acceleration would likely take the ISS to mars in a year or less without too much stress on the space station's components.

Mars landers that could return to the space station from mars could be sent to the ISS later if they were not available when the ISS left for mars. Non returnable landers might be used by crew members to set up a base on mars with the expectation that they would be able to return to ISS when returnable vehicles became available.

The ISS could also be resupplied and recrewed during its trip to mars and when it was in mars orbit. Periodically replacing ISS crew members with new crew members would reduce possible medical problems caused by space radiation and weightlessness inside the space station.

Crew members should be able to live in the space station's weightless environment for 2 to 3 years without difficulty. Cosmonaut Valeri Polyakov spent 437.7 days or about 1.2 years during one tour on the Russian Mir space station. Cosmonaut Gennady Ivanovich Padalka spent the most combined time in space with 879 days or about 2.41 years during tours on both Mir and the International Space Station. Both cosmonauts did not suffer any permanent harm from their space tours.

The next mars space station after the ISS should be a large rotating wheel or cylinder that produces an artificial earth-like gravity on its inner surface. The gravity on the rotating space station would be generated by the centrifugal force of rotation about the station's longitudinal axis. The gravity would prevent the space station's crew from losing muscle mass that would otherwise be lost in a weightless environment. The low gravity of mars would also cause the crew members on the surface to lose muscle mass. They would fly up to the space station periodically to regain muscle mass in its gravity. 

Large rotating wheel shaped or cylindrically shaped space ships with ion drives would be used to colonize all of the solar system. Single ships or groups of ships would travel to every planetary body to form permanent orbiting space colonies. Each ship would contain an earth-like gravity and environment that would enable the colonists to live on the ships. The ships would also carry landing craft to enable the colonists to construct permanent colonies on the surfaces of the planetary bodies. The materials necessary for the construction of the orbiting and surface colonies would be obtained inexpensively from low gravity moons, asteroids and comets.

Rotating wheel shaped or cylindrically shaped starships with ion drives would also be used to colonize the star systems in our galaxy with potentially habitable planets. The starships would travel near light speed so that relativistic time dilation would cause ship time to run much slower than normal time. The colonists could then to reach their destinations within their lifetimes. Only a few years  would likely pass for the colonists while many years would pass for the people that stayed behind. 

The starship engine would likely be an ion drive because it can produce a constant acceleration that would take you near the speed of light. The starship engine would be fueled by a powerful energy source such as nuclear fission, nuclear fusion and/or antimatter. A starship engine is mostly doable with current technology. New technology would be developed as necessary to complete it.

The Alpha Centauri triple star system will likely be the first star system that we colonize because it is the nearest one to our solar system. Alpha Centauri contains the stars: Alpha Centauri A, Alpha Centauri B, and the red dwarf Proxima Centauri. Proxima Centauri contains an approximately earth sized, rocky planet in orbit around in its water supporting habitable zone. The planet maybe suitable for our form of life. It may also contain its own life forms. 

Please visit the Canadian Space Agency (CSA), European Space Agency (ESA), and National Aeronautics and Space Administration (NASA), The Planetary Society, and The Mars Society websites for more information about planetary exploration and settlement. Their website URLs are listed at the bottom of this web page. The Mars and Planetary Societies would like you to become members. They would welcome your ideas, participation and commitment.