Why do Martian immigrants never return to Earth once they leave?

At this stage, to return from Mars, it is necessary to reach the escape speed of Mars of more than 5000 meters per second, and to reduce the orbit of the spacecraft in the solar system. You can think of the orbits of Mars and the Earth as two balls moving on a funnel-shaped object. The center of the funnel is the sun, and the balls with different sizes in the funnel move concentrically. They are also small funnels, and their respective satellites move in the funnel to ensure that there is no friction in their respective positions in the funnel. The speed of the inner ring is greater than that of the outer ring, but the potential energy of the outer ring is greater. Objects in the inner circle must accelerate to run to the outer circle, and vice versa. This is also the reason why it takes more time for the planets in the outer ring of the solar system to make a revolution. The so-called Mars landing time is how to bounce a glass ball from one funnel to another with as little force as possible. This glass ball will fly in the big funnel for several months. This is the Homan movement. Meet the target at the highest or lowest point of the spacecraft orbit, and then accelerate or decelerate after entering the target funnel or gravity circle. When the speed of the target is close to that of the sun, it will get rid of the control of the sun and enter the target orbit. Planets with an atmosphere can't get out or in, and planets without an atmosphere can't get out or in. Therefore, when the atmospheric density of Mars is 1%, it is more difficult to land than the Earth, and it is easier to launch. But the daily necessities are too heavy, and there is no industrial base on Mars. It is impossible to come back by immigration. After all, immigrants have to bring a lot of daily necessities to land in order to ensure the survival foundation, and so far no country has carried out large-scale landing experiments. Mars' atmosphere is not helpful for landing massive targets, and the fuel used for deceleration will not be much less than that used for launch. The landers used now are all flat and small mass objects, and parachutes can also be used, but in the end the rockets are pushed back to land. What if it is heavy? A few hundred meters in diameter? How to launch from the earth? At present, the plan to land on Mars is still far from perfect, and there are still many problems to be solved. The simplest way is to use the orbital module and the lunar module, just like landing on the moon, and run after completing the mission, which can reduce the quality of the lunar module. Don't think about hanging on it for a few months. The material that is missing for a few months will be much less than the launch weight. But when I come back, I will look at the window, plan the path and see how to get back. Horman can't move. It will take at least a few years, and only vasimr will do it hard. Otherwise, the weight of survival support materials will exceed that of fuel. Black technology, black technology, here I realize why I want to reduce the time to go to Mars. Horman can't move at all. Less fuel is transferred. After a long time, the materials are too heavy, which is prone to accidents. Moreover, after a long time, the number of times the earth has moved to the front of the orbit of Mars has also increased. At this point, we can draw a conclusion that with the current technology, we can send a lander or a returner. Anyway, if you don't eat or vent, just make a small package. Eagle sauce says that people will go in 2035. I have to ha ha, it is possible for a high-power ion engine to have kilogram-level thrust in 20 years, except that power generation and the engine itself can be five times more efficient than chemical fuel engines. I recommend you to play the game of the Kambala space program. Everything will be understood in the next real solar system and real fuel. Landing on Mars is really difficult for a big country. Just look at the propaganda films of Mars immigrants from several space companies, and you will know who believes and who is stupid. It is no exaggeration to say that the difficulty of being unmanned and manned is 1 to 1000, and the reward is 1 to 100. Let's just say that if you wait on Mars until the Long March 5 appears in the window leading to the earth, you can come back. That is, when you arrive at the earth, you need to enter the atmosphere directly, and you can't build a circular orbit to change ships. The total weight of 24 tons should be enough for several months.