What is the biggest difficulty of human interstellar travel at present?

If the human structure is not suitable, as imagined in the novel, a nano-material shell controlled by the brain is made by scientific and technological means to protect the human body and extend the human five senses. The biggest problem of interstellar travel is the need for artificial gravity. Without this, calcareous muscles will have an effect.

The human body can't be directly exposed to space, but it's no problem to put on a spacesuit, which has been proved by practice, so don't worry. As for the future development of spacesuits, we can only look at the demand, just like you wear the most advanced spacesuit to farm in the village to ensure that you go crazy first.

It is difficult to understand the possible human variation when human beings reproduce in space. Spaceships certainly don't foolishly create simulated gravity. There is no more convenient way to move and control a sci-fi film just for the convenience of shooting and reducing the cost. However, the direct consequence of weightlessness is that the organs that the human body used to adapt to the gravity of the earth will degenerate because they are useless, and some organs needed to adapt to weightlessness will be strengthened and may eventually evolve into mermaids.

It is not feasible to do interstellar flight, which lasts for thousands or tens of thousands of years. The interior of the spacecraft is an aerobic environment, and oxygen will oxidize many parts. If this problem can't be solved, interstellar flight is still possible. Impossible, the difference between drones and interstellar travel is too far. No matter how big the drone is now, it can only fly on the earth, leave the earth and fly out of the atmosphere, and fly in other galaxies. This is not simple. It can be solved by making the drone bigger. The disciplines covering all aspects are much more complicated and may not be solved for hundreds of thousands of years. The conditions of interstellar travel are not that simple. Up to now, the farthest distance for human beings is 1977. The American-launched Voyager 1 has not yet flown out of the solar system … 1977-20 19. How many years have you calculated for yourself? For example, a 20-year-old scientist arrived by Voyager 1 and is now 62 years old. When he flew out of the solar system, everyone died.