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?