Not only has NASA not gone "back" for 40 years, ESA (European Space Agency) hasn't tried it, the Soviet Union didn't try it, or Russia, or China or India. Why not?
The usual reason is that "why would they bother when the USA already did it?".
In that case, why did we go "back", if we already did it? Even after the Apollo 13 near disaster, we still went "back"!
Why did we bother to put Alan Shepard in space after Gagarin had got there first? Why did the Soviets bother with
unmanned missions after we'd already put men on the moon?
Why don't the Soviets or Russians or Chinese or Europeans or Indians plant their flag on the moon? What, they don't have technology as good as ours was half a century ago? Because that's apparently all you need to land men the Moon.
Of course, one thing we've always lead the world in is movie special effects.
