The controllable nuclear fusion engine and plasma engine used by the Ming Empire are the main engines of the Ming Empire before the development of the photon engine and antimatter engine.

However, the military and civilian views of the Ming Empire on the demand for these two technologies are different, among which controllable nuclear fusion technology is generally installed on military spacecraft, and civilian spacecraft are rarely installed on other spacecraft except for mining.

This is because the technology of the controlled nuclear fusion engine is much higher in terms of manufacturing price and the cost of spacecraft navigation, although the controlled nuclear fusion engine has absolute advantages in terms of thrust and extraordinary speed and range.

However, the spacecraft powered by a controllable nuclear fusion engine uses more than four times that of an ordinary plasma engine in the quotation format, and the cost of each voyage is more than three times that of an ordinary plasma engine, so the general civilian spacecraft of the Ming Empire use plasma propulsion technology.

Moreover, not all spaceships using plasma thrusters use gold essence batteries as an energy source, after all, most of the spaceships in the Ming Empire now belong to spaceships that can travel far away, and it is very unrealistic to use pure gold essence batteries to provide energy for spaceships.

Although the Ming Empire has also made great breakthroughs in battery technology in the past hundred years, making every kilogram of gold essence battery storage reach nearly 100 million kWh, but for long-distance spacecraft, such a little energy is simply not enough.

Therefore, those spacecraft that use conventional plasma thrusters as power, in addition to a large number of crystalline batteries as an energy source, the spacecraft itself is also equipped with controllable nuclear fusion reactors, but the role of these reactors is only to generate electricity and charge the batteries, not to directly use controlled nuclear fusion to propel the spacecraft forward like controllable nuclear fusion thrusters.

Therefore, the civilian spacecraft of the Ming Empire are basically powered by conventional plasma recommendation systems, or plasma fusion engine integrated propulsion systems.

In addition, the Ming Empire in the universe The Ming Empire also began to conduct some research on mecha during this time, but the role of mecha in space cannot be compared with space fighters at all, for which the Ming Empire also carried out several large-scale exercises, but the results were very unsatisfactory, the same number of mecha could not compete with fighters at all, and even the loss of fighters was very small.

However, the mecha has a natural advantage in land warfare, that is, landing warfare, but there is still a certain gap between the combat effectiveness of the real land king chariot, especially in terms of heavy firepower and anti-strike, but the mecha also has its own advantages, that is, the flexibility of the mecha and the survivability in special environments.

Therefore, although the Ming Empire is not very optimistic about the mecha, it still formed a ground combat unit that uses mecha, but the number is not very large, after all, although the mecha is very powerful and flexible, but he is far from the real heavy armored force suspension tank in attack power and defense, and in terms of mobility, it is much worse than the individual exoskeleton battle armor that the Ming Empire is now in active service, so the number of mecha troops is not very much.

However, although the number of mecha troops of the Ming Empire is not large, the soldiers who drive these mecha are the elite of the Ming Empire's army, which can be said to be one in a million, because these mecha can only exert the greatest combat efficiency in their hands, in fact, the combat effectiveness of the mecha is still very strong, and a mecha can even defeat a battalion of ordinary ground troops, of course, this is provided that the troops of this battalion do not have heavy firepower.

If a mech is attacking and encounters heavy ground armor such as hovering tanks, heavy vehicles, and ground fire platforms, the best way to do this is to evacuate immediately, as the mechs are useless in front of these equipment.

And in the past hundred years, although the Ming Empire has not gone to other civilizations again, it has sent explorations to all star systems within 8.5 light years near the solar system, and there are a total of five planetary systems within 8.5 light years centered on the solar system, of which star A in the constellation Centauri has long been explored, and the other four are Barnard's (Barnard's) 6.0 light years from the Earth, Woolf 359 (OLF359) 7.7 light years from the Earth, and Brande 2147 stars (BD+36°) is 8.2 light-years from Earth, and UV Cetadines (Luyten726-8) is 8.4 light-years from Earth.

These four galaxies have all been explored by the Ming Empire in the past hundred years or so. Except for the Woolf 359 star 7.7 light years away from the earth, there is a life planet, the Ming Empire has not found the existence of life on the other three planets, and even the life planet in the Woolf 359 galaxy has not yet evolved intelligent life, the whole planet is still quite primitive, this planet is still in the time when life evolves from the sea to the land, and there are no animals on the land now, but the algae and plants on the land are everywhere.

However, although this planet is a living planet, this planet is relatively primitive, and the atmosphere on the planet contains a large number of harmful gases to the human body, so although this planet is a living planet, it is not yet time for human beings to survive, if human beings want to colonize this planet, then it is necessary to speed up the process of life evolution on this planet, or remove the harmful gases on this planet, so that this planet becomes suitable for human survival.

And because human beings discovered the existence of a living planet in the Woolf 359 galaxy, the Ming Empire renamed this galaxy and this life planet, and the planet Woolf 359 was renamed Chang'an Star by the Ming Empire.

Therefore, the current territory of the Ming Empire is within 8.5 light years of the solar system as the center, after all, none of these galaxies have found the existence of intelligent life, so these galaxies automatically become the territory of the Ming Empire according to the laws of the Ming Empire.

In addition to the detailed exploration of these galaxies, the Ming Empire also sent probes to other planets within ten light years of the Ming Empire, but except for Sirius, no other galaxies have found the existence of life and intelligent life.

This is due to the probe sent to Sirius by the Ming Empire, and when Sirius was still two light-years away, the probe lost contact, and there is a record of the probe, which should have been destroyed by an energy weapon.

However, the Ming Empire still got a lot of galaxies about Sirius, and according to the information of the probe, there is intelligent life on Sirius, and the civilization level is not low, and the civilization level of the galaxy is more set, and the civilization on Sirius has at least the existence of a fifth-level or quasi-fifth-level civilization.

Although these detectors sent by the Ming Empire are relatively early products, and they are not as powerful as the current ones in terms of defense and performance, these detectors are not something that ordinary civilizations can destroy.