The generation spacecraft is an envisioned spacecraft that conducts long-term cosmic voyages far below the speed of light. On such a spacecraft, there is enough space and material to support the multiplication of a human group. Perhaps the first generation of humans cannot reach destinations hundreds or even thousands of light years away, but their offspring will arrive there one day. Before arriving at the destination, the residents on the ship will not freeze themselves, but will live, old, sick, die, get married and have children as usual. Their offspring will always live on the ship and continue to thrive.
Unless scientists make a breakthrough in the way the spacecraft is propelled, or realize the space jump technology of spacecraft, it is very likely that humans can only use generations of spacecraft for interstellar navigation.
The nearest stars and generations of spacecraft
The closest star to the sun is called Proxima Centauri, and it was discovered by Scottish astronomer Robert Innis in 1915. Proxima Centauri is a red dwarf star about 4.25 light years away from the sun (about 40 trillion kilometers). This is a star with a red surface, and its size, surface temperature, and mass are much smaller than the sun. Scientists believe that there may be stellar bodies with liquid water in the habitable zone of Proxima Centauri. In addition, Proxima Centauri is the closest stellar galaxy to the earth, so the first stop of human interstellar travel is likely to be there.
Crew overlooking the earth on a generational spacecraft
However, even with the nearest star, it will take at least 100 years for generations of spacecraft to reach there under ideal conditions. Space travelers and their descendants will live on the spacecraft for a century, or even longer. The generational spacecraft can be said to be a large, self-sufficient “space colony”.
Generations of spacecraft will be powered by nuclear fusion reactions, and the energy they produce will also be used to “create” gravity. Unlike in most science fiction movies, the crew does not live in the cylindrical hull, but in the ring that revolves around the cylindrical hull. Scientists use the centrifugal force generated by the high-speed rotating ring to simulate gravity. A magnetic field generation system called “magnetic bubble” will also be installed on the top of the spacecraft. This system can create a magnetic field similar to the earth’s magnetic field to protect the spacecraft and its residents from cosmic radiation.
However, scientists have to face various challenges and problems to create such a colony floating in space.
Nuclear pollution and shock absorbers
Between 1958 and 1963, American scientists were embarking on an “Orion Project.” In this plan, the scientists envisaged propelling the spacecraft to take off and forward by “detonating” the atomic bomb at the tail of the spacecraft. However, this plan was finally terminated by the US government. One of the main reasons was the nuclear pollution caused by the spacecraft when it took off.
Scientists estimate that a 60-meter-high, 40-meter-diameter, 4,000-ton Orion Martian spacecraft, the nuclear pollution emitted by its trip will eventually be absorbed by the Earth’s magnetic field. Hundreds of people around the world will die from this pollution by then, let alone a larger generation spacecraft. Therefore, scientists are racking their brains to see if they can at least theoretically design an engine with minimal or no nuclear pollution.
In addition, as we have seen in some media, the rocket ship vibrates violently when it is propelled. Generations of spacecraft were originally no exception, but it will have a large disk-shaped shock absorber at the bottom. This shock absorber will absorb the nuclear pulse generated by a nuclear explosion, nuclear fission reaction or nuclear fusion reaction, and then The nuclear pulse is released in a more “gentle” way, so that generations of spacecraft can obtain powerful propulsion without violent vibration. However, a shock absorber that can absorb nuclear pulses is not so easy to make, because it not only has to withstand the shock wave high temperature of at least 67000 ℃, but also can withstand the pressure caused by the shock wave. However, until now, scientists have not been able to find a qualified one. Materials to make shock absorbers that absorb nuclear pulses.
Ethics and Mental Health
Not only have generations of spacecraft encountered technical challenges, but in such a long and narrow space, each passenger will also encounter ethical, moral, and mental health challenges.
Scientists have concluded through research that generations of spacecraft need to carry at least 160 people when they set off to ensure the genetic diversity of the descendants of the crew during the flight. In this way, only two people with sufficiently large genetic differences can be together, which also means that they cannot love and marry freely. When necessary, two people who have no feeling or hate each other may even be designated as couples. How will such a move affect the children born in the spacecraft?
In addition, in order to ensure the safe and efficient operation of generations of spacecraft, everyone can only accept assigned tasks and strictly follow instructions. This means that people cannot freely choose their careers as they do on Earth, but can only painfully accept the reality that their right to choose is deprived. What impact will this have on humans?
Moreover, if a person is seriously ill and is unlikely to be cured, then for the safety of other crew members, this person is very likely to be “humanely” destroyed, even if the patient does not give up treatment.
In addition, the mental health of the crew is also an issue that cannot be ignored. After all, they have to live in a closed environment for at least 100 years and have limited resources. The crew will also know clearly that in the event of an accident, they will have nowhere to escape. Under the combined effect of these two conditions, it is easier for individual crew members to breed psychological problems such as depression, mental breakdown, and mania; for crew members, it is easier to cause “social” problems such as totalitarianism and riots.
Within 100 years, scientists are likely to have the technology to build spacecraft for generations, but because of the above-mentioned problems, people on Earth are likely to prevent generations of spacecraft from launching. Therefore, immigration to aliens may be the next policy, and more importantly, to protect today’s earth, this is the best policy.