Preparing for a human voyage that would be several hundreds of millions of miles long will require an elaborate sequence of preparations to ensure there is adequate fuel for the trip.
Our space program would have to figure out how much fuel it would need. How to store all the gas it will need is also another problem.
One idea is to have a cargo vehicle that will take scientific equipment, gas, and other materials that would be used. The cargo ship would arrive at Mars about eight months later. The cargo ship would then land on Mars with the help of a specially designed parachute. Inside the cargo ship, there would be a small vehicle. It would travel around and mix hydrogen gas from Earth with the Martian atmosphere which is about 95% carbon dioxide gas. That produces methane, a great fuel. This gas will propel an Earth Return Vehicle (ERV) back to Earth. This will be done as soon as they reach Mars as to avoid keeping the very cold hydrogen on Mars's surface.
The methane will go through many steps such as being cooled, liquified, and stored. While the methane is going through all these processes, water will be electrolyzed. This is the process of separating water into oxygen and hydrogen by running an electric current through it. The oxygen will be stored and the hydrogen will get detoured back into the methane maker.
Due to the chemical reactions 24 tons of methane and 48 tons of oxygen will be produced. It will take ten months to generate a total of 108 tons of oxygen/methane rocket propellant. The secret behind making this "brew" is using 18 parts of Martian atmosphere with one part hydrogen from Earth. Some of the fuel to make methane gas would go into some roving vehicles that travel over the Martian surface.
Stockpiles of oxygen will be used for breathing and to create water. Due to the oxygen stockpiles, we will not need to bring all the food and water necessary to sustain the explorers. These resources will be hauled to Mars on the cargo ship so humans will be ready to inhabit Mars when they get there.
The crew ship would not leave Earth until the cargo vehicle had already landed on the planet. The crew vessel would carry about six astronauts, life support supplies, and fuel for the journey to Mars. The spacecraft would be an ERV that would land on Mars without fuel for the return flight. Instead it would have about six tons of liquid hydrogen that could be turned into fuel for the trip back.
Before the crew ship would take off, two more boosters would launch. These boosters will have 40-ton payloads. One will be a fuel factory. The other will contain a habitat for four, food, enough provisions for three years, and a ground rover that runs on the methane/oxygen fuel we make from the Mars fuel factory.
An ERV will be stationed with a radio overhead to beacon where the manned craft should land. After the ERV with the crew lands, another will land away from it to start making propellant for the next mission. With the crew ship another ERV selects another landing site for a mission in another two years. If all goes successfully, every two years two boosters will be launched. One booster will be launched to land a crew and the other is to pick a landing site for the next mission. This plan will sustain our missions to Mars.
Mission to Mars. An educational site created for the ThinkQuest contest.