Can humans have children in space?

Humans have achieved the reproduction of amphibians in space, but failed to achieve the reproduction of mammals. Therefore, at present, human beings are probably unable to have children in space, and the microgravity environment will have an impact on the human microenvironment, making it impossible to have children.

The experiment of space fertility has always been a focus of scientists' research, because the current human spaceflight can not realize the permanent existence of human beings in space. Up to now, there have been about 1000 manned space flights, and a total of about 500 astronauts have been in space, but the one who stayed the longest only stayed for about two and a half years, and his return to the earth's body has been more affected. After returning to the earth, he needs long-term adaptive training to adapt to the earth's environment.

Moreover, there will be genetic changes. Astronauts who have just returned from space are generally not recommended to have children. The United States once conducted genetic testing on a pair of twins, who happened to be an astronaut and a space ground worker. It is found that the spatial microenvironment will affect the epigenetic inheritance (that is, gene expression) of human genes, thus increasing the risk of long-term cancer, with few permanent genetic changes.

Therefore, scientists have designed many biological experiments for astronauts in space. There are many breeding experiments now, and the main achievements are as follows: (1) to realize the reproduction of amphibians, fish and other relatively primitive species in space; The United States once sent the frozen sperm of male mice into space and brought them back to the ground, and found that these frozen germ cells could still make female mice pregnant and have children.

However, in the reproductive experiments in space, the reproductive activities of mammals from fertilization to childbirth have not been realized. The tenth experimental platform in China has realized the initial development of mouse fertilized eggs in space, from single-celled fertilized eggs to very early two-cell differentiation, but the experiment may have been terminated or the development may have failed, and the result has so far. In the future, scientists have plans, such as mating mice directly in space. Biological experiments show that mice can also adapt to the microgravity environment in space quickly.

At present, we continue to do space experiments. On the one hand, we study the influence mechanism of space environment on biological physiology. For example, the direct influence of microgravity environment is physiological structure. Venous blood in human body relies on the gravity of blood to avoid blood backflow, while the function of venous valve decreases in microgravity environment. So last year, scientists found that the probability of neck thrombosis in astronauts increased greatly; On the other hand, it is to prepare for future manned space flight. Once you set foot on the star road, it is normal not to come back for several years. Therefore, it is imperative to study the technology of human staying in space for a longer time. In the final analysis, human beings evolved from the gravity of the earth and the atmospheric environment, and the space environment will certainly have an impact on the human body.

In view of the fact that human beings have not yet realized the complete reproductive process of mammals in space, I personally don't think that at this stage, human beings can give birth in space without being affected. In fact, the impact on human beings in space is obvious. There are many papers in this field, and those who are interested can go and have a look.

The key to solve this problem may be to build artificial gravity facilities in space, just as large space facilities in science fiction movies can simulate gravity by rotating themselves. At least the influence of microgravity will be improved, but the existing space technology will be difficult to bear the difficulty of construction, and many countries need to cooperate to launch a large number of spacecraft to slowly assemble. There is stronger cosmic radiation in space, which will change the epigenetics of human genes, and it will be another difficult problem to be overcome.

There are rumors that a European country plans to carry out experiments on human childbirth in space. However, with the existing space technology, the acceleration of the rocket is very large, which makes the human body bear a relatively large pressure, at least 2-3 times the weight, which may be unbearable for pregnant women. Moreover, professional equipment needs to be transported to space in advance, and several professional doctors and nurses need to provide assistance during the delivery of pregnant women. Under the background of human existing space technology, it is very unlikely to carry out such an experiment, and it will probably take decades to carry out such an experiment. If we consider the safety of babies and pregnant women and the ethical constraints faced by such an experiment, it would be good to realize it within 50- 100 years.