In the 1960s and 1970s the technology didn't exist to travel to the moon.

In making this statement, conspiracists often draw parallels to the consumer technology of the 1960s. "If they couldn't make X, then how could they go to the moon?"

First we must remember that NASA was on the cutting edge of technology in the 1950s and 1960s. They had an enormous budget and attracted the top scientists in the country. At the height of the Apollo project there were half a million scientists and engineers working on different aspects of the missions.

In a larger sense, it's easy to lose touch with technology. That is, it's easy to look back to the past and wonder how we ever got along without the miracles we enjoy today. We sit at our gigahertz computers and forget that there was a time when an eight megahertz computer was pretty cool.

Just because we rely today on one particular technology or another in order to do some hard thing, doesn't mean it was impossible to do that thing before our modern technology was invented. For example, nearly all modern clocks use a real-time clock integrated circuit. It does all the timekeeping. In the 1970s we had analog clocks that used synchronous electric motors to precisely drive mechanical gears. Would it be correct to say that accurate timekeeping was impossible before that integrated chip? Of course not. Similarly, old mechanical action clocks used pendulums and springs to keep surprisingly accurate time.

What's the lesson? Just because we choose to use some particular technology today to solve a problem doesn't mean that problem was unsolvable before we had today's technology. Apollo engineers didn't have high-speed portable computers to make self-contained guidance systems, so they just built guidance systems differently. The computer was only one part of the guidance system. When John Glenn orbited the earth in his Mercury capsule, there were no computers with him. Yet his capsule was fully automated.

The moral of the story is that people can be very ingenious working with limited tools.

Many people from NASA have said it would be difficult or impossible to return to the moon anytime soon.

This, unfortunately, is probably true. But not because the technology never existed to go to the moon.

In the 1960s we had a clear mandate to go to the moon. Although NASA had an ambitious program of scientific exploration planned, the real motivation in the public's mind was to beat the Russians. After Apollo 11, interest in the space program dwindled rapidly. And consequently the budget was slashed and then slashed again.

Most of the people involved in the lunar landings have retired, and many have passed away. That is a lot of expertise to lose. A lot of that has not been passed on to the next generation of engineers because the newer engineers don't need that knowledge. Landing on the moon required a specific set of skills that isn't much in demand in the space program anymore.

Most of the equipment is gone too. A few lucky museums have command modules or lunar modules, or other significant chunks of Apollo hardware. But a lot of it has been scrapped. The manufacturers no longer have the specialized tools to build these spacecraft, and the detailed design documents have been thrown out. Not that we would actually use these machines, but today's engineers would study them to understand what their predecessors worked out for solutions to various problems.

How could these people throw out something so dear to the national heritage? Unfortunately these are private companies intent on making a profit. They are in the aircraft business, not the museum business. The plans and design documents for one lunar module take several thousand cubic feet of storage space.

NASA is, unfortunately, suffering a brain drain. While it was fashionable in the 1960s and 1970s to work for the space program, it isn't anymore. NASA is scrambling for talented scientists and engineers. There are probably two reasons for this. First, NASA isn't the same organization it was in the 1960s. Today it's more bureaucratic, more like the other government agencies. Second, much of what NASA does today is seen as routine and repetitive. The magical allure of space travel isn't what it used to be.

Henry Ford invented his automobile, and now a hundred years later the technology to produce automobiles is still commonplace. Similarly if the technology existed to go to the moon in 1969, it should still be around today.

It's not very useful to draw a parallel between technology that was intended from the start to be a mass-produced consumer product, and a highly specialized technology, only twenty or so items of which would ever be produced. There just isn't a big market for manned spaceships. The companies that produced them in the 1960s and 1970s went back to making conventional aircraft. Some of what they learned making the Apollo spacecraft was incorporated into their more consumer-oriented products, but some wasn't.

There were processes involved in making lunar spacecraft that were known literally to only a handful of people. They were the people who invented them. These techniques aren't necessarily needed into today's aerospace market, and so they weren't passed on when those people retired. Most automotive engineers can't make a wheel for a horse-drawn covered wagon. It's not technology that's required much anymore, so it's not generally passed down through the ranks of automotive engineers.