>>13846119Sending disposable probes to Venus and Mars (which btw, Mariner 6 was both the first probe to orbit another planet and the first to Mars, beating Soviet attempts) is orders of magnitudes less difficult than landing and returning human beings from the Moon.
A probe is basically just a computer bus, some solar panels or an RTG, a few instruments and cameras, and a control system with a little propellant and a thruster.
A moon landing on the other hand requires either two small man sized space craft (a command vehicle and a lander), both of which are probably as bigger or bigger than what a traditional ICBM can get into orbit or on a planetary intercept. Or it requires one fuckhuge ship that can land itself and get back. In any case you also need to bring atmo, water, food, and other living accomodations for the crew. Scientific instruments, power, etc, but it all needs to be of much larger scale than the probe because a living human being(s) requires far more resources to survive than a computer bus with some instruments.
Aside from that, in a flyby or orbital probe, your orbital mechanics only needs to work 2-3 times. Once during launch on a direct launch, once during orbit, and once again at the planet in question if you plan on orbiting it. Landing and safely returning humans from the moon requires 5-6 steps, all of which can kill people if they fail, because you have to do all the above, land on the moon, leave the moon, and return to the Earth. Just as a final consideration re entry from a lunar return is also orders of magnitude faster than returning from LEO so your command pod needs to be able to survive temps and forces that would easily destroy most other manned space craft.
Since you can't get it through your thick skull, the most basic property of rocketry is that the more mass you move, the more powerful your rocket needs to be, and the more propellant is required to reach the target destination.
