It came too suddenly.
Before the delta-winged space shuttle took off, the Z nation had never made any official announcements about any plans to perform a manned landing on the moon.
According to the established plan, the first step to establishing a moon landing was to realize the orbit of the detection satellites around the moon. This step had been accomplished in 20X7, 17 years ago.
The second step was to realize the unmanned probe's landing on the lunar surface, deploy small lunar exploration vehicles and let it roam about the surface of the moon. This step had been accomplished 11 years ago through the launch of "Chang'e 3."
The third step was to launch a large, unmanned detector, land on the lunar surface, use robots or mechanical arms to collect lunar soil, put it into the return capsule, and launch the return capsule carrying the lunar soil back to Earth. This step was attained in the year 20X0.
