In 2031, after receiving the green light on the status of all systems on Mars, the Mars Transit Vehicle (MTV) will be prepared for the journey to Mars. First, a transit habitat and a Mars lander with an assembly crew aboard will be launched into Earth orbit. The assembly crew will dock the Mars lander to the transit habitat. About thirty days later, two propellant stages and the boosters that will "kick" the transit vehicle from low Earth orbit to Mars transfer orbit, will be launched and connected. Once that has been successfully completed, the first fully trained Mars crew will be launched into the same Earth orbit to switch places with the assembly crew, which will descend back to Earth. After a final check of all systems on Mars and on the transit vehicle, engines of the propellant stages will be fired and the MTV will be launched into a Mars-transit trajectory. This is the point of no return for the Mars crew. Read more about the Mars Transit Vehicle. The cargo for the second crew will be launched toward Mars in the same month as the launch of the first Mars settlers Before the first crew begins its journey, the ECLSS will have produced a breathable atmosphere of 0.7 barometric pressure, 3,000 liters of water, and 240 kg of oxygen which will be stored for later use. Read more about the life support units and the ECLSS. The rover will also deposit Martian soil on top of the inflatable sections of the habitat to shield it from radiation. Read more about radiation protection