Apollo 11 landed on the moon over 40 years ago. Yet many people still claim -- some quite stridently -- that it never happened. They insist that it was all a hoax.
These people go by numerous terms: conspiracy theorist; Apollo hoax theorist; hoax believer, etc. I have coined the admittedly pejorative terms "hoaxhead" and "hoax monger", but they don't seem to have caught on. A few use the term "hoaxtard", but that sounds like a word used by seventh graders. "Conspiracy theorist" is accurate but too general. "Hoax believer" (HB) is a somewhat ambiguous term (does one believe in the hoax, or that it was a hoax?) but it seems to be the most common term so that's the one I'll use.
The sheer inanity of the "logic" behind their arguments is difficult to appreciate. It begins with their basic structure. They resemble in one very important way those made by creationists and many other pseudo-scientists: their "evidence" is entirely negative. The so-called "arguments for creationism" (or intelligent design) consist entirely of attacks on perceived weaknesses in the theory of evolution. Similarly, no HB has ever produced any affirmative evidence from someone who directly planned or perpetrated the alleged hoax. They don't even seem to try. They merely point to so-called "anomalies" in the official record (particularly photographs) that, they say, prove no landing ever happened.
Like the creationists, the HBs attempt to create a false dichotomy: if even a small part of the standard theory or record is wrong, then all of it must be wrong. They hope to win purely by default.
The Apollo program attracted an intense public following, and this made it the topic of many books, magazines and films by non-NASA authors. As an agency of the US federal government, NASA's materials are in the public domain, encouraging their use in derived works by outside parties. Two of the more remarkable third-party projects on the Apollo program are the Apollo Lunar Surface Journal and Apollo Flight Journal. These started as personal projects by highly motivated individuals, attracted a following and turned into collaborative works. Although NASA does not control the editorial content of these works, they now sponsor their distribution on the Internet. They also provided very high quality digital scans of the original 70mm, 35mm and 16mm photographic images taken during the Apollo missions.
The Apollo record even includes certain documents that were originally classified CONFIDENTIAL, including transcripts of private crew conversations, medical data, and rocket performance reports. These all seem to have been declassified without any redactions.
The Apollo project is thus one of the most thoroughly documented events in history. The extensive record establishes the reality of the Apollo program beyond reasonable doubt, but ironically it fuels the Hoax Believers' purely negative strategy of attacking the record instead of presenting affirmative evidence for their case.
HBs are especially fond of the Apollo image archive. They try mightily to prove that this or that Apollo picture was faked or at least doctored. So far, they have succeeded only in finding artifacts accidentally added during scanning or copying and intentional changes to correct composition or exposure errors in the original picture.  These changes invariably disappear or are readily explained by merely going back to the originals. But in true HB fashion they claim this proves someone is trying to cover up the evidence! One simply can't win with them. In any event, the HBs have never demonstrated an actual case of anyone within NASA modifying an Apollo picture with an intent to deceive. However, this cannot be said about the HBs.
Yet even were the HBs to succeed in showing that some particular picture was created or modified with an intent to deceive, that's as far as it would go. That still wouldn't prove that no one ever landed on the moon. 
They avoid this at all costs because the HBs simply don't have such a story. Just as there are "young earth" creationists and "old earth" creationists, some Apollo HBs believe that none of the Apollo landings were real, while others believe that some were real and others were not. Some think the Apollo crews remained in earth orbit the whole time, others think they never went into space at all. There are as many stories as there are HBs. Perhaps more. (And a few UFO enthusiasts who stumble on the conversation by accident believe that Apollo was perfectly real but that NASA has been hiding the alien artifacts they discovered on the moon.)
Although my goal in this essay is not to refute every claim made by the HBs (other sites do this very well) I will discuss some of them for insight into the style of arguments that the HBs use and how and why they are logically fallacious.
The single most important and fundamental fallacy underlying the HB arguments is an improper assumption of where the burden of proof lies. They frequently challenge their critics to "prove" that Apollo was real, but it is really up to the HBs to prove their extraordinary contention that it was not real. And extraordinary claims require extraordinary proof.
Why so? The answer can seem somewhat philosophical, but there are some very sound reasons for placing the burden of proof on the claimaint.
One very practical reason is just about anyone can make a wild and unsupported claim with relatively little effort, but painstakingly debunking even the most frivolous claims can take a lot of time and effort from experts. Quite frankly, most of them have better things to do.
But even this isn't enough of a reason; after all, once in a great while the generally accepted theory or principle is wrong and the seemingly wild-eyed outsider turns out to be right. It does seem a little unfair to handicap them against the whole scientific establishment.
But science does not seek fairness; science seeks the truth, and the rules have evolved to what they are over centuries because they have been shown to be the most effective way to get at the truth. For every Theory of Relativity that succeeds brilliantly there are hundreds of incorrect theories that fade into deserved obscurity. And some that don't fade simply because their authors don't know when to quit.
There is a more fundamental and philosophical reason for placing the burden of proof on the claimant: science can never actually "prove" anything. We can only disprove. We can find contradictions between the predictions of a theory and our empirical observations, and if the observations are correct then the theory must go or at least change. When a theory has has been found to be compatible with a very large amount of evidence, and if it makes predictions that can be tested with experiments that also produce consistent evidence, then it becomes established and accepted. But it is still in principle subject to being overturned by or at least modified in response to new evidence.
This brings out another fundamental property of every scientific theory: falsifiability. There must, at least in principle, be some experiment or evidence that could conceivably overturn the theory. If it is not possible to even conceive of a test that could overturn the theory, then it is simply not scientific though it may still be a perfectly good topic for philosophers or theologians. This issue can be seen in the way many HBs argue. Whenever you show them information generated by or about an Apollo mission, their near-instantaneous response is to say that it was faked. Rarely do they give any evidence to support their contention; they simply say that it could have been faked, therefore it cannot be used as evidence for the reality of Apollo. When you point out that they haven't shown any indications that the evidence was indeed faked, they respond that this is merely because the fakery is of very high quality. The problem, of course, is that a fake that is of such high quality that it cannot be distinguished in any way from the genuine article is a non-falsifiable claim. There is no answer, nothing that one could say to prove that the article or item is genuine and not a high quality fake that can't be distinguished from the real thing. This is perhaps the most important reason why the burden of proof is properly placed on the HB claimants. [......]
A good example of the HB argumentation style involves an excerpt from the video record of Apollo 15. During the second EVA, Jim Irwin and Dave Scott have just erected the US flag and are taking pictures of each other standing next to it. We watch through the TV camera on the nearby Lunar Rover. After they finish picture taking, Dave Scott walks between the camera and the stationary flag. After he passes, the flag swings slightly and eventually stops. "Ah ha!", exclaim the HBs. "This was shot on earth on a soundstage with an atmosphere; the astronaut disturbed the flag with his wake as he passed!"
Why is this conclusion incorrect? There are several reasons. The most obvious and fundamental is that the HBs have failed to rule out the other ways that Scott may have disturbed the flag. Every proper forensic investigation starts by listing every conceivable explanation for the phenomenon in question. This is the time to let your imagination run wild. So the list can include the possibility, however unlikely, that the scene was faked on an earth set with an atmosphere as the HBs allege. But he may simply have brushed the flag with his left side as he passed, or he could have kicked up some lunar regolith that hit the flag or its staff, or there may have been an electrostatic attraction between the nylon flag and the pressure suit and life support system covered with beta cloth (Teflon-coated fiberglass), or gases emanating from the life support system may have disturbed the flag.
The next step is to walk down the list of possibilities evaluating each one against all of the available evidence. If a hypothesis conflicts with the evidence, then either the hypothesis or the evidence must go. Hopefully, when you are done, only one explanation remains. It becomes your conclusion, yet you still can't say that you've actually "proved" it; you can only say that this is the most likely explanation that you could think of that fits the available evidence. But it could still not be the right one; you may have completely missed the true explanation.
Because Scott blocks our view at the critical moment, we simply don't know (without further analysis) whether he touched the flag. Although at first glance it looks as though Scott was too far in front of the flag to have touched it, this is not necessarily so. The TV camera had a zoom lens set at wide angle, and wide angle lenses tend to exaggerate depth, sometimes quite considerably. A photometric analysis of the video and the still pictures taken from the side at the same time is inconclusive; it doesn't show that he must have hit it, nor does it show that he could not have hit it.
Here we come to a critical part of the analysis. Whatever conditions were in effect at the moment the flag began to move were most likely in effect through the entire scene. That is, if air was present on the "soundstage" at the moment Scott moved the flag, it was almost certainly also present a minute earlier and a minute later -- unless the "soundstage" was rapidly pumped to a vacuum or vented to the atmosphere. That raises the question: what happens at the other times an astronaut walks closely by the flag? At one point another astronaut does indeed walk closely by the flag, this time behind it so we can see how close he came. The flag does not move at all. Now if the hypothesis is that the "soundstage" had air, shouldn't the flag have moved every time that an astronaut walked closely by? The fact that the flag doesn't move these other times allows us to rule out the HB's theory that an air current was responsible the one time it did move. Only one candidate is left, so we can conclude that the flag moved most likely because Scott brushed it as he passed, probably with his left arm.
The HB make many claims like this one. They take one picture, one brief excerpt of video, or one line of dialogue and claim that it alone proves the entire Apollo program was fraudulent.
Despite the false dichotomy implicit in their negative argumentation, HBs readily concede that hoaxing the moon landings would be by far the largest, most elaborate and the most successful hoax in human history. Yet the notion that a hoax so huge could remain totally airtight for four decades is simply beyond credulity. Nothing else even comes close. Known conspiracies and hoaxes on a far smaller scale have repeatedly fallen apart in far less than 40 years. The Watergate break-in and related Presidential wrongdoing was revealed within a year of its occurrence. President Nixon was forced to resign after only about two years. The Iran-Contra scandal came to light only about a year after the fact. Some Apollo HBs repeatedly stress the huge scale of the alleged Apollo hoax to stroke their own egos at having "cracked" something so important without realizing that they are merely underscoring its implausibility.
Space telecommunications was one of the things that inspired me to get into ham radio (I was first licensed in 1971), earn two college degrees in electrical engineering (Cornell University in 1978 and Carnegie Mellon University in 1979), and ultimately a rewarding career in the communications and computer field.
To show the scope of the communication systems used by Apollo (and how far we've already come since those days) I'm putting together some link budgets for a few Apollo missions. A "link budget" is an accounting, generally done on a spreadsheet, of the signal and noise powers on a communications link. It starts with the radio frequency (RF) power generated at the transmitter and computes how much of it reaches the receiver input over the specified distance with the particular transmission lines and antennas at each end.
The link budget separately computes the equivalent noise level at the receiver input from a variety of sources including the receiving equipment, the antenna, various celestial sources and even the cosmic background from the Big Bang. It then compares the two to produce the signal-to-noise ratio (SNR).
The bottom line is the link margin - the difference between the actual SNR and the minimum required for the particular modulation type and information being sent. A positive link margin indicates a working link; a negative margin indicates that the link is not working.
These are Excel spreadsheet files; they can also be read by Open Office and Neo Office, among other 3rd party spreadsheet programs.
In my opinion, the single best such site and the one to check out first is Moon Base Clavius, organized by Jay Windley. Another is by Phil Plait, the self-described Bad Astronomer; he was spurred to action by the appalling Fox TV "documentary" Conspiracy Theory: Did We Land On The Moon?.
Youtube has a 9-part video of a 2007 talk by Peter Barrett of the Canberra (Australia) Skeptics titled Why The Moon Hoax Makes No Sense. He also has an excellent list of questions to test conspiracy theories that apply quite generally, not just to the Apollo hoax conspiracy theory.
 We saw the HBers curious "logic" in action with a recent news story that a "moon rock" given to a Dutch museum by a former Dutch government official was actually a piece of petrified wood. Some HBs claimed, apparently seriously, this proved Apollo wasn't real. Of course, it only proves that this particular "rock" wasn't genuine; NASA still has hundreds of kg of real moon rocks brought back by Apollo, and countless scientists around the world have studied them. NASA's role is scientific research and science education, not supplying a collectibles market, so they do not give them away as trophies. But many individual collectors would certainly like to own a moon rock. Because they are not generally available, some have gone as far as stealing them from laboratories. It is not at all implausible that an especially dishonest individual might steal a real moon rock and replace it with a fake, or simply sell a fake moon rock to a collector with more dollars than sense. Obviously there wouldn't even be a demand for them if no one thought the genuine articles existed on earth. In any event, anyone can go to a museum with a moon rock on display and assure him or herself that it is not petrified wood.