As for the Star-Level Shelter's current invisibility and anti-invisibility technologies.
They were developed jointly by Earth Civilization's finest local scientists.
And top scientists from those Star Systems that had submitted to Earth Civilization and willingly become its affiliated civilizations.
Under the day-and-night efforts of the joint research team.
They had finally achieved a breakthrough.
Just how formidable was the Star-Level Shelter's invisibility technology now?
Even if they used an ultra-high-power Energy Detection Radar with a base magnitude one hundred times greater.
Or the most advanced anti-invisibility energy detection radars currently available to all civilizations.
And brought them within one million kilometers of the Star-Level Shelter.
To conduct uninterrupted, round-the-clock surveillance and detection.
They would still be absolutely unable to discover the Star-Level Shelter's existence.
Even if Li Chen and the others sang and danced inside the Star-Level Shelter.
With all kinds of ultra-high-power instruments, research equipment, weapon systems, and so on.
Operating at full power.
The enemy still would not be able to detect the slightest energy fluctuation.
That was the true power of the most advanced invisibility technology currently mastered by the Star-Level Shelter.
And there was something else to understand.
The definition of invasion established by one civilization for another.
As well as the safe range set for weapon systems, was fifty million kilometers.
In other words.
Once an unauthorized target entered within fifty million kilometers of a civilization.
It was considered an act of invasion.
And it would be directly exposed to the range of all that civilization's weapons, as well as the detection range of its Energy Detection Radars.
After being automatically locked onto by Energy Detection Radars combined with Fire Control Radars, it would be attacked automatically.
In other words, the safety distance commonly recognized by those Tier 3 Universe Civilizations.
Was fifty million kilometers.