They'd be propelled to another world with no atmosphere and so far from the Earth that our planet would become a blue marble small enough to hide behind an outstretched thumb. Then they'd have to be lowered to the surface, somehow. You can't use parachutes in a world without air.
No one knew with absolute certainty whether the moon's surface would support the weight of an astronaut, much less a space-ship. There was a maverick hypothesis that the lunar module—the little dinghy that would descend to the surface with rocket thrust—might simply sink on landing. Or maybe moondust would, on contact with oxygen inside the lunar module, burst into flames.
The astronauts needed to find a level spot to land in that cratered mess, because if the lunar module tipped over on its side, they'd never get off the moon. Going to the moon wasn't the hardest part of the mission—getting home was. They'd have to launch from the moon, rendezvous in lunar orbit with the command module, then fire their engines yet again to rocket back to the Earth, where they'd reenter the atmosphere at—italics alert—seven miles a second. They'd create a giant fireball and finally parachute into the middle of the Pacific Ocean, where they'd hope someone would be kind enough to find them.
At the time, space enthusiasts viewed the moon landing as the first of many bold forays beyond Earth. But predictions of the future are reliably wrong. It turned out that the moon landing wasn't the beginning of an inexorable, progressive conquest of space. Or at least it didn't ignite a Buck Rogers future. If anything, it signaled the end of an era. Americans were thrilled by Apollo 11 and strangely bored by Apollo 12. The drama of Apollo 13—the glorious failure that may have been NASA's finest moment of all—helped remind the public that going to the moon wasn't as easy as throwing a Frisbee. But even as Neil Armstrong and Buzz Aldrin walked on the moon, Project Apollo was being trimmed. NASA, under pressure from congressional bean counters, canceled several planned moon missions. We came, we saw, we conquered, and then we cut the budget.
The post-apollo era has had its signature triumphs, such as when astronauts aboard the space shuttle have repaired the Hubble Space Telescope. The construction of the International Space Station is a remarkable engineering accomplishment. But somehow the simple goal of exploration got lost in the bureaucracy of the space program. The stated goal of the space shuttle, to make spaceflight routine, was both impossibly ambitious (it has cost two shuttle crews their lives and remains dangerous) and politically unwise (because people got bored with it).