Making an informed decision on which specific destinations warrant sending human explorers requires more data than what the best Earth-based telescopes can provide.
We have sent explorers to those mountains several times, but if any of them reached Chiribu, certainly none of them ever got back to England.
He sends explorers out to other lands.
But even if we don't find him, we'll have to send explorers through sooner or later.
We have sent explorers into the lands there, and they are good lands.
That's where we'll send explorers first.
Only Saito Yamagata knew that its true goal was to provide the power to send human explorers to the stars.
To this end, I am sending explorers through the Death's Gate into each of the four worlds.
"We sent occasional explorers here," the human said.
For more than thirty years he had traveled the world, pleading with those in power to send human explorers to Mars.