it would only take a single rocket to terraform mars. A genetically engineered strain of Chroococcidiopsis paired with a genetically engineered endolithic Mycorrhiza fungal network could act to release carbonates from the kilometer or more of mars's deep carbonate reserves. this could be tailored to produce a 30% earth pressure atmosphere of co2 which would them be transformed into a 30% earth pressure oxygen atmosphere which is breathable and high enough pressure. this bacteria and fungal symbiotic network could also reduce perchlorates from the soil using perchlorate reducing enzymes similar to those on earth, it could also reduce the hexavalent chromium in the soil too.
>inb4 " hur dur im a fucking nigger, mars has no magnetic field and im too dumb to understand it isn't a problem over the lifespan of human civilisation because it is lost over a 1.47 billion year time period "
even if it were a problem, a artificial magnetosphere would be easy to produce at L1, NASA is suggesting to do so already. it would be a 500 tonne satellite that is refuelled with 40 tones of fuel every year or perhaps beamed to it using lasers. the bacteria fungi symbiotic network could also produce large amounts of sulphur hexafluoride into the atmosphere to raise temperatures to similar levels to global averages on earth, and over time we could slowly introduce nitrogen from outer solar system sources. but initial raising temperature, pressure, and detoxifying soil could take less than 10 years with one seed rocket to infect mars with a genetically tailored symbiotic organism.