What are some of the problems that needed to be overcome in order for NASA to be able to land men on the moon?

In addition to the funding comments (which are true) there is its predecessor, "political will" to do it. We have the technology (all we have to do is spend a lot of money to reconstruct the Apollo system, including Saturn V and the rest. Having done it once (actually half a dozen times) 40 years ago, it could be done again if someone was willing to do (and pay for) it. I can read your question differently -- we had (back in the 1960s) to develop reliable rocket systems, the technology for docking, navigation, soft landing, subsequent take-off, and controlled re-entry at 25,000 miles per hour (normal low orbit re-entry is at about 17,000 miles per hour, and so there is about twice the energy per unit of mass that has to be dissipated on re-entry. Reliable deep space (out of Earth orbit) communications was also a good thing to have. Long term (like up to a week or more) of life support systems was another necessity.

One big problem was to develop the ability to rendezvous in Moon orbit. This was initially considered very difficult, but simulations in mid 60s showed that it is actually more reliable than attempting a direct mission with no rendezvous. Another big debate was about the nature of Moon's surface, particularly about the amount of dust. Technologically, the biggest problem was likely the miniaturization of electronics.

One big problem was to develop the ability to rendezvous in Moon orbit. This was initially considered very difficult, but simulations in mid 60s showed that it is actually more reliable than attempting a direct mission with no rendezvous. Another big debate was about the nature of Moon's surface, particularly about the amount of dust. Technologically, the biggest problem was likely the miniaturization of electronics.

Well, we deconstructed the Saturn V... the only rocket strong enough to get us there, and the military gets more funding for AC in military camps in the middle east than NASA gets for everything. There was a time when we were concerned about space, and with the resources we have being finite, Id like to see us colonize the moon and beyond

Funding

Those problems were all overcome in 1969. .

Now or before? now= more funding. Then, I dunno, testing and reaserch?

Wow, the educational system is doing a great job of teaching our students. I've read the alleged "proof" we did not land on the moon. I would ask, since Russia and the USA were not on the best of terms during the cold war, any ANY failure on sending a man to the moon would have been immediately picked up and continually brought up to this day. Then there's the sheer size of the Saturn V rocket, as tall as a 35 story building. Where might we have put that once it left the ground. Everyone saw it leave the Earth. There is not stealth in space, Russia could have and did, track the mission as closely as NASA did. We landed on the moon, several times. Forget what hippy teachers have said. "If we landed on the moon, why can't we see stars?" Answer, the moon doesn't have an atmosphere and the sun is very bright, wiping out any contrasts and subtle shades. Duh! "How is it the picture as so perfectly centered with cameras that big?" "It's not hard to take a centered picture without looking through the viewfinder. Double duh! And what would happen if the astronauts brought back crappy photos? "Geez, ya'd t'ink with all the money they spent they could get some decent pictures." We haven't been to the moon since because of politics and budget constraints. Plus other space exploration projects. Remember, we can't spend extra money on space exploration, we have to give it all to people who don't want to work. Edit: There is solar wind, enough to make light objects like flags, ripple. But in the news films, you can see the astronaut move his hand back and forth getting the flag pole to borrow into the moon's surface. The motion obviously was transferred to the flag making it move. Triple-Duh!

Well, we deconstructed the Saturn V... the only rocket strong enough to get us there, and the military gets more funding for AC in military camps in the middle east than NASA gets for everything. There was a time when we were concerned about space, and with the resources we have being finite, Id like to see us colonize the moon and beyond