Apollo 10's lunar module Snoopy descended toward the lunar surface, but (as planned) didn't quite make it, returning to orbit only 8.4 nautical miles above the surface of the moon. Was there a technical reason why Snoopy couldn't land on the moon?
By technical, I mean...
- equipment not yet designed, manufactured, or delivered.
- software not yet written.
- NOT the fact that the objective of the mission was to be only a "dress rehearsal" for landing (not a technical reason).
- NOT a lack of training (not a technical reason).
- NOT the fact that NASA intentionally under-fueled the LEM, to deter the astronauts from making a landing attempt (a deliberate reason):
Craig Nelson wrote in his book Rocket Men that NASA took special precaution to ensure Stafford and Cernan would not attempt to make the first landing. Nelson quoted Cernan as saying "A lot of people thought about the kind of people we were: 'Don't give those guys an opportunity to land, 'cause they might!' So the ascent module, the part we lifted off the lunar surface with, was short-fueled. The fuel tanks weren't full. So had we literally tried to land on the Moon, we couldn't have gotten off."