Phobos Base One, to wit, the proper course for colonizing Mars would be, rather to dive down into its gravity well, set up a base on its moon Phobos.
Phobos is tidally locked to Mars, and so the planet-side of the moon will be forever locked on the planet. From Phobos Base One, techs can use remote robots to build a habitable base on Mars. Phobos' proximity to Mars will mean this process will not be plagued with the time lag which we would face if we tried to do this from Earth. Yet, because the techs would not be stuck deep in a gravity well, they will be able to come home again.