8.1 Wouldn’t the camera films have melted on the Moon?IN A NUTSHELL: No. The temperature extremes often mentioned by conspiracy theorists refer to the lunar surface, from which the films were insulated by vacuum, like in a thermos flask, and in any case were not reached during the Apollo missions, which landed on the Moon shortly after the beginning of the two-week-long lunar day at the landing sites, when ground temperatures were far lower. The film was also a heat-resistant type used for high-altitude reconnaissance and the cameras were treated to reflect the heat from direct exposure to the Sun, which is comparable with the heat from sunlight on a mountaintop on Earth.
THE DETAILS: Gerhard Wisnewski is one of the many hoax theorists who claim that the extreme temperatures of the lunar surface would have damaged the camera films irreparably and therefore the photographs must be fake. In his book One Small Step, Wisnewski argues thus:
There was no other protection against temperature extremes of over 100°C plus and under 100°C minus [...] It was to be expected that the sensitivity of the chemical films would be affected by the extreme temperatures – if indeed not rendered useless by temperatures of over 100°C.
However, a little fact-checking shows that Wisnewski’s premise is incorrect due to a common misconception about temperatures in space.
First of all, the extreme values mentioned by Wisnewski are reached only after lunar midday (which entails seven consecutive Earth days of uninterrupted exposure to the Sun) and just before sunrise (after fourteen Earth days of continuous darkness). Data from recent lunar probes, such as the Lunar Reconnaissance Orbiter, show maximum temperatures of 110°C (230°F) and minimum temperatures of -180°C (-292 °F) at the lunar equator; in some polar regions, which are perennially in shadow, the temperature plunges to -238°C (-397°F).
But all the Moon landings took place shortly after local sunrise, when the temperatures were far from these extremes. The maximum elevation of the Sun above the horizon during the Apollo moonwalks was 48.7°, at the end of the third excursion of the Apollo 16 crew. This mission recorded temperatures of 57°C (135°F) in sunlight and -100°C (-140°F) in shadow.
Secondly, all these values refer to the temperature of the lunar surface. But on the Moon there’s nothing to carry that heat from the ground to the films: there’s no significant atmosphere that can be heated by the ground and therefore there is no conduction or convection through air, which is the main heating process on Earth. Vacuum is a very good heat insulator, as thermos flasks demonstrate. On the Moon and in space, heat is transferred between objects that are not in mutual contact only by radiation: the same principle by which we are warmed when standing next to a fire. Clearly the heating produced by radiation is nowhere as intense as heating by direct contact: there’s a significant difference between warming your hands in front of a fire and putting your hands in the fire.
Consequently, on the Moon the temperature of the ground is essentially irrelevant as regards film temperatures and claiming that ground temperatures would overheat the films is a misleading and amateurish scientific error.
Moreover, an object exposed to the Sun on the Moon receives essentially the same amount of heat that it receives on Earth on a mountain top on a clear day, since heat transfer by radiation depends on the distance from the heat source and the Earth and the Moon are essentially at the same distance from the Sun. There’s nothing magically incendiary about the sunlight that strikes the Moon: in terms of heat, it’s roughly the same that we receive here on Earth.
In other words, a film exposed to sunlight on the Moon is affected by the same level of thermal stresses that affect it on Earth on a bright sunlit day on a high mountain. As we all know, tourists are quite able to take photographs in the mountains and even in the heat of tropical forests or deserts without their film melting or spoiling its colors.
One might object that on the Moon the sunlit side of the camera is heated intensely while the shadow side cools just as dramatically. However, these processes are not instantaneous, because once again there’s no air to carry the heat from the camera body to the film or away from the film into space. The camera is in vacuum and therefore the film is like in a thermos flask. Heat transfer between the film and the camera occurs only at their few points of mutual contact.
Besides, if someone argues that it’s impossible for film to withstand the vacuum and the temperatures on the Moon, then he or she is implying that all the photographs ever taken on film in space during Russian and American spacewalks are fake, because there are no differences, in terms of temperature, vacuum and exposure to sunlight, between the conditions on the Moon and those in Earth orbit.
For example, Figure 8-1 shows US astronaut Ed White during his spacewalk outside the Gemini 4 spacecraft in 1965. He is carrying an ordinary camera (circled) and his picture was taken with another camera, which also was outside in space. Neither of the films in these cameras melted or was spoiled.
Figure 8-1. Ed White used an ordinary camera (shown circled here, in front of the astronaut’s chest) during his spacewalk in 1965. NASA photograph S65-30431.
Moreover, the Apollo lunar cameras had been treated specifically to have reflective surfaces instead of the traditional black finish. This treatment reflected most of the heat received from the Sun.
In addition, lunar photography didn’t use ordinary film, but a special 70 mm Kodak film engineered specifically for high-altitude reconnaissance applications, in which it had to deal with temperatures as low as -40°C (104°F). This film had a custom-made thin polyester base (Estar), with a melting point of 254°C (490°F), and used an Ektachrome emulsion capable of providing adequate results over a wide temperature range.
Sometimes it is objected that chemical films have a narrow temperature range, so much that professional photographers are very careful to keep their films warm or cool as needed. But this is an optimum range, which yields the best possible colors: it doesn’t imply that the film will break or melt outside of this interval.
8.2 How come the Van Allen radiation belts didn’t kill the astronauts?IN A NUTSHELL: Because these belts are not as deadly as they’re often made out to be and also because they’re belts, so you can fly around them. Russian spaceflights flew animals through them without problems. NASA also conducted sensor-laden uncrewed test flights to measure the effectiveness of the shielding of the Apollo command module. The trajectories of all the moonshots were calculated to fly around the core of these donut-shaped belts and pass rapidly through their less intense outer portions.
THE DETAILS: Many Moon hoax proponents claim that any crewed lunar mission would be impossible due to the lethal barrier of the Van Allen belts, two regions of radiation that wrap around the Earth at distances that can vary according to solar activity but are roughly located between 100 and 10,000 kilometers (62 to 6,200 miles) for the more intense inner belt and between 18,000 and 60,000 kilometers (11,100 to 37,000 miles) for the weaker outer belt (Figure 8-2).
Figure 8-2. A graphical representation of the Van Allen belts.
Vintage technical literature on the subject (for example the papers listed in the References chapter of this book) shows that the potential danger posed by the Van Allen belts was well-known when the lunar missions flew (the belts had been discovered in 1958) and was considered perfectly manageable.
In 1968, the Soviet space probe Zond 5 flew through the Van Allen belts to carry around the Moon several living creatures, which returned unharmed from their voyage. For the Apollo missions, exposure during the crossing of the Van Allen belts was calculated and measured by means of uncrewed test flights: specifically, Apollo 6 (April 1968) carried into Earth orbit an empty Apollo capsule equipped with instruments for measuring the capability of the spacecraft to block the radiation from the belts. It was found that the exposure was comparable to the effects of a few medical X-rays and therefore was quite tolerable.
The very first human beings to fly beyond the Van Allen belts were the astronauts of Apollo 8. According to NASA’s Biomedical Results of Apollo report (1975), over the course of the entire flight Lovell, Borman and Anders accumulated a radiation dose of 1.6 millisieverts. This is the equivalent of about twenty chest X-rays and is therefore far from being immediately lethal as some conspiracy theorists argue.
Moreover, the Apollo 11 Mission Report notes that the total radiation dose measured by the dosimeters and received by the astronauts during the trip was between 2.5 and 2.8 millisieverts. The Van Allen-specific dosimeter detected doses of 1.1 millisieverts for the skin and 0.8 millisieverts for the depth reading, well below medically significant values.
For comparison, according to the US National Council on Radiation Protection and Measurement the annual average radiation dose per person in the United States is 6.2 millisieverts; 52% of this is of natural origin.
We don’t have to take NASA’s word about the Van Allen belts. There is clear consensus in the science community on the matter, as shown for example by the article The Van Allen Belts and Travel to the Moon by Bill Wheaton, specialist in gamma ray astronomy at the Jet Propulsion Laboratory (JPL).
Wheaton provides objective data regarding radiation in space and specifically in the most dangerous region of the Van Allen belts. It turns out that the data published by NASA on this subject must be true, otherwise today’s automatic satellites would be fried, since they fly through the belts and their equipment, if not shielded adequately against radiation, will malfunction.
James Van Allen, from whom the belts get their name, had already stressed, as early as 1960 in the article On the Radiation Hazards of Space Flight, that these belts don’t encase the entire planet from pole to pole, but form a sort of donut that fades in intensity from approximately 30° above and below the Earth’s equator. Therefore, to fly around them or pass through their weaker regions it is sufficient to use an adequately inclined trajectory, which is what all the Apollo spacecraft did, both on the way to the Moon and on the way home (Figure 8-3).
Figure 8-3. The outbound trajectory of Apollo 11. The return path was even more inclined. Source: Rocket & Space Technology.
Records show that Apollo 11’s transit through the Van Allen belts lasted a total of 90 minutes, flying around the region of maximum intensity in about ten minutes.
8.3 How come deep space radiation didn’t kill the astronauts?IN A NUTSHELL: Because radiation normally present in space at lunar distances from Earth is comparable to the radiation received by the astronauts on the International Space Station, who stay in space up to six months at a time. A round trip to the Moon lasted no more than twelve days.
THE DETAILS: It is often claimed that the lethal radiation of deep space would have killed the Apollo astronauts who went to the Moon, since they spent several days outside of the safety of Earth’s protective magnetic field, which provides a shield against this radiation.
However, the claim’s premise is factually incorrect: on Earth we’re protected against deep space radiation mainly by the atmosphere, not by the planet’s magnetic field, which has a small role in shielding us. The dose of cosmic radiation (ions traveling at nearly the speed of light) that reaches anyone who lives at sea level is approximately 0.3 millisieverts/year, which is the equivalent of a couple of chest X-rays. This rises to 0.8-1.2 millisieverts/year for people living at high altitudes, for example on a 3,000-meter (10,000-ft) mountain range. At 12,000 meters (40,000 feet), the usual altitude of airline flights, cosmic radiation rises further to 28 millisieverts/year: nearly a hundred times more than at sea level, even though the aircraft’s occupants are still well within the Earth’s magnetic field.
Once you leave the atmosphere, this radiation increases considerably right away. In low earth orbit, such as on the International Space Station, it averages 100 millisieverts/year. At this altitude, the protective effect of the Earth’s magnetic field becomes significant, but only for astronauts who follow equatorial orbits; the ISS has a highly inclined orbit. In interplanetary space the dose is 130-250 millisieverts/year and by some estimates may be as high as 800 millisieverts/year on a trip to Mars; on the surface of the Moon it drops to 70-120 millisieverts/year.*
* Shielding Space Travelers, Eugene N. Parker, emeritus physics professor at the University of Chicago and member of the National Academy of Sciences, in Scientific American, March 2006.
In other words, the doses of deep space radiation to which the Apollo vehicles were exposed are comparable to those that affect the International Space Station, yet the occupants of the ISS stay in space for up to six months without dying of radiation exposure, compared to a maximum of twelve days for the lunar astronauts during Apollo 17.
8.4 Shouldn’t X-ray radiation in space have fogged the films?IN A NUTSHELL: No, because the X-ray doses received in space by the films during a Moon trip would not have been strong enough. The tests performed by conspiracy theorists use flawed methods and vastly exaggerated doses compared to those to which films might be exposed during a trip to the Moon and back.
THE DETAILS: In the book Dark Moon, Mary Bennett and David Percy describe tests conducted by physicist David Groves: films exposed to X-rays became fogged or their pictures were deleted. Therefore, they claim, the same should have happened to the films taken to the Moon.
However, these tests exposed the film to X-rays directly, without any protection, whereas the lunar films were kept for almost all of the journey inside shielded canisters, which in turn were protected by the shielding provided by the Apollo spacecraft in the Command Module and in the Lunar Module. Even during the moonwalks, the films were shielded by the metal of their Hasselblad magazine.
Groves’ tests also bombarded the test films with an 8-MeV (million electron volts) beam, using a linear accelerator, while astronomers report that X-rays from space have an energy level of less than 5 keV (thousand electron volts), i.e., approximately 1,600 times weaker than the radiation that fogged films in the Groves experiment.
This difference is crucial not only in terms of numbers, which show how unfair the tests presented by Bennett and Percy are, but also in terms of the shielding required: X-rays with an energy of less than 5 keV are stopped by a few sheets of paper. Under 3 keV, just a few dozen centimeters (inches) of air are all that it takes.
Groves reports that he exposed the test films to 25, 50 and 100 rem of radiation, but this unit is wholly inappropriate, because it refers to radiation absorbed by human tissue. Using it for films suggests an unprofessional approach to the matter: it’s like saying that distances are measured in liters (or gallons). However, for X-rays 1 rad is equivalent to 1 rem, so we could assume that Groves meant doses of 25 to 100 rad. Even so, 25 rad (the lowest figure claimed by Groves) are equivalent to several years in space.
8.5 Wouldn’t sunlight have burned or boiled the astronauts’ faces?IN A NUTSHELL: No. If so, then it should also do the same to the faces of astronauts who routinely perform spacewalks outside the International Space Station, since sunlight on the Moon is essentially the same as in Earth orbit. But it doesn’t.
THE DETAILS: Some Moon hoax proponents argue that the fiercely strong sunlight on the Moon, unfiltered by the Earth’s protective atmosphere, should have caused intense sunburns or overheating, yet we see photographs and footage of the moonwalkers walking around in full sunlight, sometimes even with their protective visor up (Figure 8-4).
Figure 8-4. Harrison Schmitt’s reflective visor is up in a frame from the Apollo 17 moonwalk TV transmission.
However, the Apollo helmets were designed to protect the moonwalkers adequately both against the ultraviolet solar radiation that causes sunburns and the infrared radiation that causes heating: perhaps not unsurprisingly, these issues had been anticipated and solved during mission planning and suit design and had been tested during spacewalks in the early Apollo flights in Earth orbit, where sunlight is essentially as intense as on the Moon.
There is a common misconception that infrared and ultraviolet protection was provided only by the golden reflective visor and therefore walking around with the visor up would have been impossible or extremely hazardous, as argued for example in Bennett and Percy’s book Dark Moon (on page 102). Actually, this protection was provided both by the clear part of the helmet and by the reflective visor and therefore the astronauts could lift the visor when needed, for example in low-light conditions or for a memorable photograph. The visor was mostly intended to reduce the brightness of the sunlight, much like a pair of oversized sunglasses.
This is the same principle that is used today by astronauts working outside the International Space Station and was used in the past by Skylab, Shuttle and Mir spacewalkers. They, too, are exposed to full sunlight without the shielding of the Earth’s atmosphere, yet don’t get sunburned or overheated; and they, too, often lift their reflective visors with no problems, as shown for example in Figure 8-5.
Figure 8-5. Jerry L. Ross working outside the Shuttle Atlantis (1991). NASA photo STS037-18-032.
Moreover, temperatures measured on the surface have nothing to do with sunburns, as anyone who’s been sunburned during a cool day in the mountains, with snow or ice on the ground, knows all too well. Sunburns are caused by ultraviolet rays in direct or reflected sunlight, not by heat.
The Apollo technical manuals explain that lunar astronauts wore a pressurized helmet (the inner goldfish-bowl transparent enclosure) inside an outer helmet. The inner helmet was made of Lexan, which is very tough and, most importantly, highly opaque to ultraviolet rays. The outer helmet in turn had an inner visor, which filtered ultraviolet and infrared radiation, and an outer visor (the gold mirror-like surface visible in many photographs) that filtered visible light (like mirror shades) to prevent dazzling and provided a further barrier to ultraviolet and infrared rays.*
* Biomedical Results of Apollo, Section 6, Chapter 6, Pressure Helmet Assembly.
Essentially, the moonwalkers didn’t get sunburned for the same reason why you don’t get sunburned if you drive around in your car with the windows up: the transparent material allows visible light to get through but blocks the ultraviolet light that causes sunburns.
Astronauts, both on the Moon and in Earth orbit, often raise their golden visor when they are in shadow and sometimes don’t bother to lower it when they move back into sunlight, but in any case the multiple helmet layers still protect them against sunburn. The worst that can happen to them is that they are dazzled by the bright sunlight.
8.6 How come meteoroid showers didn’t kill the astronauts?IN A NUTSHELL: Because meteoroids capable of piercing an astronaut’s multilayer spacesuit or a spacecraft are actually incredibly rare. The suits and the vehicles had protective layers designed to absorb the impact of the minute specks that constitute the vast majority of meteoroids. There is no protection against larger meteoroids other than the very low probability of being struck, but this is an acceptable risk, as demonstrated by the fact that satellites, space probes, crewed spacecraft and the International Space Station don’t get riddled by meteoroids.
THE DETAILS: The Moon is pock-marked with craters produced by meteoroids: rocky or metallic masses of all sizes that travel through space and can strike the Moon at speeds up to 80,000 kilometers per hour (about 50,000 mph). Although the terms meteor and meteorite are often used, strictly speaking a space rock is a meteoroid when it travels through space: it becomes a meteor only if it punches into the atmosphere of a planet or moon and forms an incandescent trail and then becomes a meteorite if it reaches the surface of the planet or moon instead of disintegrating completely.
Looking at the Moon, it’s understandable that someone might wonder how the moonwalkers coped with this constant lethal danger. The answer is actually quite simple: they relied on probability. Meteoroid showers aren’t as frequent and dense as often depicted in Hollywood sci-fi productions. If they were, our fleets of satellites that provide us with weather data, TV programs and telephone calls would be destroyed all the time and the International Space Station would be Swiss cheese after over a decade in space. Several automatic probes have been traveling through deep space for three decades or more and have survived essentially unscathed.
Actually, most meteoroids are literally microscopic in size. They have an enormous speed, but an almost negligible mass, so if a micrometeoroid strikes an astronaut it is stopped by the spacesuit’s outer layer, which is designed for this purpose. The space suits used by the Apollo moonwalkers and the ones used today for work in space have essentially the same type of multilayer protection against micrometeoroids. That’s one of the reasons why they’re so bulky.
Non-microscopic meteoroids are quite rare. While the Moon’s cratered surface might appear to suggest otherwise, one must bear in mind that those craters are the result of millions of years of exposure. Apollo astronauts and all lunar spacecraft (including the Russian Lunokhod rovers) had a vanishingly small chance of being struck by a significant space pebble.
8.7 How could the astronauts have changed film magazines outside on the Moon?IN A NUTSHELL: They had cameras with magazines designed to allow film changes even in direct sunlight and while wearing the spacesuit’s bulky gloves, as shown in the TV transmissions from the Moon. This wasn’t an exceptional technological innovation: the same feature was part of any professional photographer’s equipment in the 1960s.
THE DETAILS: Some Moon hoax theorists argue that astronauts on the Moon couldn’t change the film of their cameras while wearing the clumsy, bulky gloves of their spacesuit and while they were in full sunlight, yet the mission records don’t report that they ever went back into the lunar modules to reload their cameras. So how were they able to take thousands of photographs?
The answer is quite simple but clever: the films used for the Hasselblad cameras taken to the Moon were kept in light-tight magazines that snapped onto the camera body (Figure 8-6) and were designed to be changed even in full sunlight. The same method was used by professional photographers of the time to change films even halfway through a roll.
Figure 8-6. Snap-on mounting of a film magazine on a Hasselblad EL/M camera, similar to those used on the Moon. Lunar magazines were larger than the one shown. Credit: PA.
Not all missions, moreover, changed films during their excursions outside the spacecraft. For example, the Apollo 11 moonwalk made do with a single magazine.
Handling the film magazines while wearing the thick gloves of a lunar spacesuit wasn’t a problem because the magazines were cubic objects about 10 centimeters (4 inches) wide on each face (Figure 8-7) and had been modified to have larger grip rings, so as to allow easy removal of the so-called darkslide (a removable metal lamina designed to protect the film, Figure 8-8) even with gloves.
Figure 8-7. Charlie Duke is holding a film magazine and is about to change it outside on the Moon. Frame from the Apollo 16 TV transmission.
Figure 8-8. A standard Hasselblad magazine with its partially extracted darkslide. Credit: Ulli Lotzmann.
In standard Hasselblad cameras that used a film magazine, the darkslide was removed after the magazine had been attached to the camera body. This allowed to change film mid-roll, without exposing any frames to the light. Lunar Hasselblads instead required the astronauts to remove the darkslide before coupling the magazine to the body of the camera. This difference was due to the presence of a reseau plate, i.e., the glass plate that carried the cross-shaped markings that are visible in most Apollo photographs taken on the Moon, and entailed that the portion of film that was visible during a magazine change would catch the light and become unusable. However, this wasn’t a problem in the particular case of the lunar astronauts, who usually didn’t need to change magazine mid-roll.
The astronauts, moreover, usually took three or four blank shots when they started and ended a magazine, so as to make the film advance and be sure to use a part of the film that had not been exposed to light inadvertently.
Figure 8-9 shows a film magazine used on the Moon during the Apollo 11 flight. If you compare it with the magazine of Figure 8-8, you’ll notice that the darkslide pull ring, on the right, was much larger in the Apollo magazines to allow to use it even while the astronauts were wearing gloves on the surface of the Moon.
Figure 8-9. Magazine R of the Apollo 11 flight, currently on display at the National Air and Space Museum of Washington, D.C. Note the larger ring used to pull out the darkslide while wearing spacesuit gloves. Credit: NASM.
8.8 Isn’t it impossible to cool an astronaut in a vacuum?IN A NUTSHELL: No, it isn’t: you just have to transfer the astronaut’s heat to the water reserve in their backpack and then discard the heated water. Exposing the water to the vacuum of space freezes it, removing even more heat from the astronaut’s suit.
THE DETAILS: People who are not familiar with spacesuit technology are sometimes puzzled by the idea of maintaining a comfortable temperature inside a thick, bulky insulating suit that is in the vacuum of space and goes from being exposed to full sunlight to standing in total shadow, with consequent extreme temperature variations. A vacuum would seem to be an almost perfect insulation into which it might appear impossible to dump excess heat. It obviously rules out the use of a compressor like those used in air-conditioning units.
Yet Russian and American astronauts have been performing spacewalks since the 1960s and have since been joined by astronauts of many other countries, so clearly there must be a technology that allows to keep an astronaut cool in a vacuum, otherwise one would have to claim that every spacewalk ever made was faked (and still is, since spacewalks are routine events on the International Space Station). Many of these spacewalks didn’t rely on umbilicals (long hoses that supplied air, power and temperature control to the suit) but used self-contained equipment located in the spacesuit backpack, so they were (and still are) very similar to moonwalks.
During lunar excursions, the heat generated by the astronaut’s body was captured by a tight-fitting undergarment, known as Liquid Cooling Garment, in which water was circulated inside a web of fine tubing. This method is still used today for modern spacesuits. The heated water then entered a heat exchanger, located inside the suit’s backpack (Figure 8-10), where it released its heat to a water reserve of approximately four liters (8.5 pounds), which was increased to 5.2 liters (11.5 pounds) in later moonwalks.
This water then reached a sublimator, where it was slowly and gradually exposed to the vacuum of space. The consequent pressure drop, in accordance with the laws of physics, made its temperature fall: the water would freeze on the outer surface of the sublimator and turn directly from ice to water vapor, which was discharged through an appropriately provided duct.
This system allowed to dissipate up to 2,000 BTU/hour (approximately 580 W): enough to air-condition a small room and therefore more than adequate for cooling the inside of an astronaut’s suit, so much that John Young, for example, remarked that even the intermediate setting made him feel freezing cold if he was resting.
Figure 8-10. The inside of an Apollo spacesuit backpack or PLSS. Credit: Ulli Lotzmann/NASM.
8.9 How come there’s no blast crater under the LM’s engine?IN A NUTSHELL: Because there’s not supposed to be one. The idea that the lunar module’s engine should have formed a crater upon landing was suggested by some artist’s illustrations published by NASA ahead of the Moon landings. But the crater is merely an artistic license: the engineers already knew that no crater would form because the Surveyor uncrewed probes had already landed and sent back pictures of their landing sites, which showed no crater under their engines.
THE DETAILS: Bill Kaysing argues that the Lunar Module mysteriously failed to blast a crater in the surface of the Moon with its powerful rocket engine.
NO CRATERS! [...] In all pictures of the LEM on the “moon”, there is absolutely no evidence of a crater underneath the engine. If indeed the module had landed on the moon, the engine would have blasted out a substantial hole in the dustlike surface of the moon.
– We Never Went to the Moon, page 75.
Kaysing repeats the claim in the FOX TV documentary Did We Land on the Moon? (2001):
“The fact that there is no blast crater under the LM is one of the most conclusive pieces of evidence that I find supporting the hoax.”
But if a blast crater was expected, why would the alleged fakers be so clumsy as to forget to sculpt one into their lunar movie set?
Actually, the expectation of a blast crater under the LM was fostered by many artistic depictions of the Moon landing that were circulated by NASA and by the press ahead of the event, as witnessed for example by Figure 8-11. But mission planners didn’t really expect the LM engine to gouge a crater in the Moon: that detail, like many others in artists’ illustrations, was dramatic license.
Figure 8-11. The Moon landing as depicted by NASA in 1966. Detail from S66-10989.
Artistic depictions are, well, artistic: they’re not intended to portray an event with absolute fidelity, but to bring the event to life, explain it and communicate its significance, drama and excitement. If accuracy gets in the way of the message, it is often set aside. For example, Figure 8-11 includes stars, despite the fact that stars are not visible from the Moon when the lunar surface is in daylight, and the LM is shown without its characteristic protective “tin foil” (thermal blankets and micrometeoroid shielding).
The presence of a crater under the LM in illustrations doesn’t prove that the landings were faked: it proves the talent of the artist who found a way to suggest the dynamic action of the engine’s exhaust in a static image. Essentially, Kaysing was mistaking artwork for hard science.
Actually, not all NASA illustrations show a crater under the Lunar Module. Figure 8-12 is an artist’s concept created for Grumman (the company that designed and built the LM), in which there’s no blast crater and the LM is depicted far more realistically than in Figure 8-11 (note, for example, the MESA equipment rack and the exhaust deflectors under the attitude control thruster quads). However, the stars are still shown in order to give depth to the artwork and the Earth is too low on the horizon for any Apollo landing site.
Figure 8-12. An artist’s concept of the LM created for Grumman before the first Moon landing. NASA image S69-38662.
Leaving artistic license and conspiracy theories aside, why didn’t the rocket blast of the LM form a crater or visibly disturb the surface? After all, the Lunar Module was a 15-ton spacecraft, so it needed a powerful engine to counter that weight and make it hover. Instinctively, we expect that kind of force to do some damage to the landing site.
But first of all, lunar gravity is one sixth of the Earth’s, so the LM’s weight on the Moon isn’t 15 tons; it’s 2.5. Moreover, these figures refer to the initial weight of the spacecraft, which decreased dramatically as its rocket fuel was used up. For example, for Apollo 12, which had an initial LM mass of 15,115 kilograms (33,325 lb), telemetry data reported the use of approximately 7,810 kilograms (17,200 lb) of propellant mass,* leaving a landing mass of approximately 7,305 kilograms (16,104 lb), not 15,115 kg (33,325 lb). The spacecraft essentially halved its initial mass by burning propellant, and in lunar gravity that residual landing mass is equivalent to a weight of just 1,217 kilograms (2,700 lb).
* Apollo 12 - The Nasa Mission Reports, Apogee Books, 1999, p. 44 and p. 137.
In other words, keeping a LM in a hover above the landing spot entailed countering a weight of just 1,200 kilograms (2,700 lb), not 15,000 (33,000 lb); far less than assumed initially. Since the surface of the Moon consists of hard rock covered by a layer of dust, the rather modest rocket thrust actually required would merely blow away the dust and expose the underlying rock. That’s exactly what we see in the Apollo photographs (Figure 8-13).
Figure 8-13. Apollo 11’s LM descent engine bell on the Moon. Note the dust-free, smooth, rocky surface in the foreground and the radial pattern formed on the surface by the engine exhaust. NASA photo AS11-40-5921.
The LM rocket exhaust might be expected to melt the lunar rocks at the landing spot, but the estimated temperature of the exhaust was approximately 1,500 °C (2,800 °F)* and decreased very rapidly because the hot plume expanded into a vacuum and therefore cooled down, like any other expanding gas.
* The Blast Crater, Clavius.org.
Moreover, it takes several minutes of intense heat to melt the kind of rocks that form the surface of the Moon, whereas the LM’s exhaust struck the same surface spot only for a few seconds. There simply wasn’t enough heat or time to cause significant melting or cratering. What we do see in the Apollo photographs is a slight discoloration, possibly due to charring or to a chemical reaction of the propellant with the rock, and traces of fluid erosion.
No crater was expected by mission planners due to direct previous experience: the automatic Surveyor probes had landed on the Moon between 1966 and 1968, sending back TV pictures of the landing site and chemical and physical tests of the lunar surface, which showed no cratering and indicated a compact rocky nature that allowed safe touchdown. The Apollo astronauts didn’t fly into the absolute unknown; they had a fairly good idea of what to expect.
8.10 How could the timing of the lunar liftoff footage be so perfect despite the signal delay?IN A NUTSHELL: Because it was calculated in advance. Liftoff time was known to the second and the rate of ascent was known precisely, so the camera operator compensated the delay by tilting the camera up 1.3 seconds early with a predetermined rate of motion.
THE DETAILS: In his Wagging the Moondoggie website, conspiracy theorist David McGowan considers with suspicion the spectacular TV footage of the liftoff of Apollo 15, 16 and 17 from the Moon. This footage was shot with the Rover’s TV camera, which was controlled by radio signals from Earth. Considering that the radio commands to move the camera took about 1.3 seconds to travel from the Earth to the Moon and the resulting TV picture took just as long to be received on Earth, how could the camera operator track the ascending Lunar Module? “There apparently either wasn’t any delay in the signal or NASA had the foresight to hire a remote camera operator who was able to see a few seconds into the future”, argues McGowan.
Actually, the remote camera operator (Ed Fendell) could see more than a few seconds into the future, in a way, because the liftoff time of the Lunar Module was known very precisely in advance. Exact timing was critical, otherwise the LM would not be in the right place at the right time to rendezvous with the Command Module once in orbit around the Moon. The delay caused by the Earth-Moon distance was also known very precisely. So Fendell knew exactly when to send the commands: about 1.3 seconds ahead of the scheduled liftoff time. The rate of tilt depended on the distance of the camera from the LM and had to be calculated carefully.
The first attempt at this remarkable shot (during the Apollo 15 liftoff) failed because the tilting mechanism malfunctioned and the camera didn’t tilt up. The second attempt (Apollo 16) went better, but the Rover was parked closer than expected to the LM and this threw off the calculations, so the camera lost track of the LM quite early. The third attempt worked out perfectly, and Apollo 17’s lunar liftoff was tracked until the LM became a tiny bright speck on the TV screen.
8.11 Why is there no dust on Apollo 11’s LM footpads?IN A NUTSHELL: Because dust moved by a rocket exhaust in an airless environment such as the Moon will not billow up around the spacecraft and then settle on it: it will travel in straight lines away from the vehicle, unhindered by any air resistance, and therefore is unlikely to end up on the vehicle’s footpads.
THE DETAILS: Photographs of Apollo 11’s lunar module footpads on the Moon show them to be completely dust-free (Figure 8-14). To some this seems suspicious. Shouldn’t the engine blast have blown at least some dust onto the footpads? Says Bill Kaysing in the 2001 documentary Did We Land on the Moon?: “If they had truly landed on the Moon, this dust would have then descended on the lunar lander, on the footpads, and we find not a trace of dust on the footpads.”
Figure 8-14. A spotless Apollo 11 footpad. NASA photo AS11-40-5920 (cropped).
However, the lack of dust on the footpads doesn’t prove that the spacecraft was actually a mockup delicately placed on a movie set and that the hoax perpetrators incredibly forgot to spread some dust on the footpads to make the scene more realistic. There’s a simpler, less conspiratorial explanation: on the Moon, dust doesn’t “descend” as Kaysing suggests, simply because it doesn’t rise and float in the first place.
The Moon is airless, so there’s no atmosphere to carry the dust and allow it to form billowing clouds that then settle. The dust simply gets blown sideways and outward, racing roughly parallel to the ground and away from the landing spot, and then falls down at the end of its essentially rectilinear trajectory, without floating around. This effect is visible in the footage of the Apollo lunar landings and liftoffs.
Moreover, in a vacuum only the dust that is struck directly by the exhaust gets moved, so the displacement is very localized (on Earth, such a displacement has a broader action because the exhaust displaces the surrounding air, which in turn displaces dust, spreading out the effect). Indeed, the Apollo 11 photographs show pebbles and dust a short distance out from the footpads, as evidenced in Figure 8-14 by the footprints behind the LM’s landing gear.
The dust that is moved, however, can travel quite a distance at high speeds, since there’s no air resistance to slow it down and the low gravity drags it down more gradually than on Earth. On Apollo 12, dust displaced by the LM exhaust reached the Surveyor probe, roughly 200 meters (650 feet) from the LM, as evidenced by the sandblasting detected on the side of Surveyor that faced the LM.*
* Watch Out for Flying Moondust, by Trudy Bell and Dr. Tony Phillips (2007), Nasa.gov.
8.12 Why are Apollo 11‘s footpads clean while later missions have dusty ones?IN A NUTSHELL: Because the other Lunar Modules landed in other regions of the Moon, which were geologically very different (e.g., more dusty), and sometimes landed less gently than Apollo 11, so their footpads dragged on the ground, scooping up dust. The astronauts also occasionally kicked dust into the footpads as they walked close to the LM landing gear. Lack or presence of dust on the footpads is not evidence of fakery.
THE DETAILS: While Apollo 11’s lunar module landing gear is immaculately dust-free, the footpads of other lunar modules are very dusty. Compare, for example, Figure 8-14 (Apollo 11) with Figure 8-15 (Apollo 16). According to some doubters, this conspicuous difference proves that Apollo 11 was faked badly (forgetting to sprinkle dust on the footpads) but later missions were faked better, correcting this omission.
Figure 8-15. A dusty Apollo 16 LM footpad. NASA photo AS16-107-17442 (cropped).
Once again, a conspiracy theory is based on the assumption of bungling perpetrators: for some bizarre reason, the most important fakery of the century was assigned to a bunch of sloppy amateurs who made all sorts of mistakes and left evidence in the photographs, and somehow their bosses didn’t notice the mistakes before releasing the pictures to the public.
The difference in dust can be explained quite simply without resorting to farfetched tales of colossal incompetence. First of all, the Apollo missions landed in geologically very different sites in order to acquire the broadest possible variety of samples: Apollo 11 and 12 landed on very flat terrain; Apollo 14 touched down in a broad, shallow valley; and Apollo 15, 16 and 17 landed in the highlands of the Moon. Compare, for example, the Apollo 11 site (Figure 8-16) with the Apollo 17 site (Figure 8-17).
Figure 8-16. Composite panorama of the Apollo 11 landing site (photos AS11-40-5930/31/32/33/34/39/40). Credit: NASA/Moonpans.com.
Figure 8-17. Composite panoramas of the Apollo 17 landing site. Credit: NASA/Moonpans.com.
It seems reasonable to assume that vastly different locations might have different dust coverings. Indeed, Pete Conrad (Apollo 12) and Dave Scott (Apollo 15) reported that they had to fly on instruments for the final 30 meters (100 feet) of their landing because the dust kicked up by their engine’s exhaust obscured their view of the surface, while other LM pilots didn’t have the same problem.
Moreover, some landings were quite rough. Apollo 11 landed very smoothly, but Apollo 14, for example, dragged its landing gear sideways after touchdown. This caused the footpads to scoop up moondust, as shown for example in NASA photo AS14-66-9234. Apollo 15 landed with one footpad in a 1.5-meter (5-ft) deep crater, damaged its engine exhaust bell and came to rest at a steep angle. Its footpads dug quite deeply into the ground and got very dusty.
Finally, dust could also accumulate on the footpads after landing, for example if the astronauts worked close to the LM’s landing gear (as in Figure 8-15). As they walked around, they kicked up dust which, in a vacuum and in low gravity, could travel quite far and end up on the footpads.
8.13 How can the astronauts’ footprints be so sharp?IN A NUTSHELL: They’re as sharp as they should be in dry, jagged moondust in a vacuum, which behaves quite differently than weathered sand in Earth’s atmosphere.
THE DETAILS: In NASA Mooned America!, Ralph Rene claims that “clear tracks in deep dust require moisture; otherwise they form only indistinct depressions [...] There can be no moisture on the Moon [...] And yet, every picture allegedly taken on the Moon shows clear footprints” (page 7). In other words, sharply outlined bootprints such as the famous one shown in Figure 8-18 are said to be impossible on the Moon.
Proponents of this claim, however, fail to consider that sand on Earth is exposed to very different conditions than dust on the Moon. First of all, on Earth, the wind, the flow of water and other natural phenomena move and churn the grains of sand against each other constantly, smoothing their surfaces and reducing their friction. On the Moon this smoothing doesn’t occur, and therefore the grains of lunar “sand” (termed regolith in geological jargon) are sharp-edged and uneven. Accordingly, they tend to lock together and stick to each other far more than Earth sand, much like a stack of smooth river stones will collapse easily while a similar pile of jagged rocks will keep its shape. This leads to higher cohesion and sharper footprints.
Figure 8-18. A footprint left on the Moon by Buzz Aldrin (Apollo 11). Detail of photo AS11-40-5877.
Then there’s gravity, which is one sixth of the Earth’s. Stacked moondust particles are pulled down by weaker forces than on our planet and therefore the edges of footprints, for example, hold their shape more easily.
Finally, there’s electrostatic attraction. Lunar regolith has a considerable electrostatic charge and therefore its grains tend to cling to each other more than ordinary Earth sand, in the same way that dust clings to an electrostatically charged glass surface, such as an old-style (CRT) television screen.*
* Effects of gravity on cohesive behavior of fine powders: implications for processing Lunar regolith, Otis R. Walton, C. Pamela De Moor and Karam S. Gill, in Granular Matter, vol. 9 no. 6 (2007).
The sharpness of prints in moondust is confirmed by the Russian uncrewed rovers of the Lunokhod series, which landed on the Moon and sent back pictures of their finely detailed wheel tracks (Figure 8-19).
Figure 8-19. Sharp-edged wheel tracks left on the Moon by Soviet Lunokhod 1 in 1970.
In 2008, the Mythbusters TV show placed a sample of powdery material, geologically equivalent to lunar regolith, in a vacuum chamber and then pressed a footprint into it, using a replica of an Apollo Moon boot. The result closely resembled the sharp-edged footprints seen in Apollo photographs, despite the higher gravity and the lack of any significant electrostatic charge.
8.14 Wasn’t the lunar module hatch too narrow?IN A NUTSHELL: No, it wasn’t. People who claim that the spacesuit was too wide to pass through the hatch are referring to the width of the suit when spread flat and with the arms at its sides, but the suit is much narrower when worn and moonwalkers crawled through the hatch on all fours and therefore with the arms tucked under their bodies, not at their sides. All this reduced the actual suit width dramatically, allowing it to pass easily through the hatch. Besides, if the whole thing had been faked, it would have been trivial to fake a comfortably bigger LM hatch.
THE DETAILS: Mary Bennett and David Percy, in their book Dark Moon, argue that “the aperture of the LM is only 32 1/4 inches wide [...]. Surely, it would be very difficult for a pressurised, spacesuited astronaut, fully loaded with his PLSS and measuring over 31 inches in width to exit through such a small and awkward aperture” (pages 340-341).
The width of the LM hatch quoted by Bennett and Percy is essentially correct, as confirmed by NASA’s Apollo 11 Press Kit and Lunar Module Operations Handbook. However, their measurement of the width of a suited astronaut is definitely wrong, because it refers to the spacesuit laid flat and with the arms at the sides of the flattened torso of the suit (as shown in the photograph on page 341 of Dark Moon). Any garment measured in this way will appear to be much wider than when it is being worn, because it’s not wrapped around the wearer’s body. Try this for yourself: your sweater, when spread flat, is much wider than your body. Basically, Bennett and Percy are confusing girth and width.
This mistake is compounded by the fact that the Apollo astronauts crawled out through the hatch on their hands and knees and therefore held their arms tucked in under their bodies, not at their sides as shown in Dark Moon. This reduces further the actual width of the spacesuited astronaut.
There’s a very simple way to check all this. The hatch width reported by Bennett and Percy, 32 1/4 inches (82 centimeters), is the width of an average interior house door. The widest part of a suited astronaut’s body is at the shoulders, so try standing in a doorway and notice how much clearance you have on either side. Even if you take into account a bulky Apollo spacesuit, there’s still room enough to walk through easily. The backpack (PLSS) wasn’t a problem, because it was about 51 centimeters (20 inches) wide. If you really want to be thorough, buy or rent a replica Apollo spacesuit (available from specialist dealers), put it on and compare its actual width with the hatch of an original LM, such as the one on display at the National Air and Space Museum in Washington, DC.
Besides, Apollo photographs such as AS11-40-5862 (Figure 8-20), which shows Buzz Aldrin as he exits the lunar module through the hatch, clearly demonstrate that the hatch was wide enough. Exit certainly wasn’t easy, but it was feasible.
Figure 8-20. Buzz Aldrin exits from the Lunar Module to walk on the Moon. NASA photo AS11-40-5862 (cropped).
There’s another logical rebuttal to any claim of an impossibly narrow hatch or cramped LM interior: if the whole Apollo project was faked, there would have been no point in skimping on the size of the spacecraft. Why not simply fake a slightly bigger LM with a wider hatch and avoid any questions about hatch size?
8.15 How come the pressurized spacesuits didn’t balloon?IN A NUTSHELL: Because they had a containment layer, just like present-day spacesuits, and the outer layer wasn’t pressurized.
THE DETAILS: Some Moon hoax proponents wonder how astronauts could flex their fingers inside the bulky gloves of their spacesuits and more generally how they could move at all, since the suits, if pressurized as NASA claims, would have inflated like balloons in the vacuum of space and would have become impossibly rigid. Yet Apollo photographs show astronauts on the Moon moving around quite comfortably, with suits that show no sign of ballooning and are actually flexible and surprisingly creased and saggy.
This objection can be dismissed simply by considering that the American, Russian and Chinese spacesuits currently worn by astronauts during spacewalks on the International Space Station and in Chinese spaceflights are quite obviously flexible and don’t balloon, so there must be a way to solve these allegedly unsurmountable problems. That way is essentially the same one introduced by Russian and American spacesuits of the 1960s.
The Apollo spacesuits were pressurized to approximately one third of sea-level pressure; this helped to reduce the suit’s tendency to balloon. This lower pressure was countered by a non-elastic containment layer of mesh, integrated in the neoprene layer that formed the so-called Pressure Garment, i.e., the airtight part of the suit that enclosed the astronaut’s body. In other words, the suit could only expand until this mesh was taut. If you can imagine a balloon placed inside a bag of netting, or if you look at a garden hose, you have a good example of a pressure containment layer.
The fingers, shoulders, knees and elbows of the suit had accordion-like joints that allowed flexing without ballooning. Moreover, the spacesuit was actually two suits worn one over the other: the inner Pressure Garment (Figure 8-21) and the white outer unpressurized protective suit (Figure 8-22), designed to withstand fire, abrasion and micrometeoroids and provide thermal insulation.
Figure 8-21. Gene Cernan checks the fit of the airtight inner layer of the Apollo spacesuit, known as Pressure Garment. Note the accordion-like joints at the elbows and fingers. NASA photo AP17-72-H-253.
Figure 8-22. Left: Charlie Duke (Apollo 16) tests the flexing of his Pressure Garment. Right: Ron Evans (Apollo 17) checks the upward reach of his arm while wearing both the inner Pressure Garment and the white outer protective suit.
In summary, the Apollo spacesuits don’t look like they’re pressurized simply because what we normally see is their outer layer, which indeed wasn’t pressurized.