6.5 Were the astronauts lifted by wires when they fell?

IN A NUTSHELL: No. Their movements on the Moon seem odd because they weighed less than 30 kilograms (66 pounds) including their suit, and their spacesuit and backpack displaced their center of gravity considerably upwards and backwards. Also, they used the spring-like elasticity of the suit to get back up, as practiced in training.


THE DETAILS: The way the astronauts regained their footing after a fall on the Moon appears unusual and too easy to non-expert viewers. But on the Moon the Apollo astronauts weighed one sixth of their Earth weight due to the lower lunar gravity, which is indeed one sixth of the Earth’s. Their backpack and spacesuit weighed a total of approximately 81 kilograms (180 pounds) on Earth, which became a mere 13.5 kilograms (30 pounds) on the Moon. Their body weight was likewise reduced: an 80-kilogram (178-pound) person on the Moon weighs 13.3 kilograms (29.3 pounds).

In other words, on the Moon a fully suited astronaut weighed a total of about 30 kilograms (66 pounds). Getting up after a fall, therefore, was trivial in terms of effort. Doing it without toppling over again, however, was challenging.

The way the astronauts got back on their feet looks unusual because in addition to being in one-sixth gravity they were carrying a backpack (known as PLSS) which was quite heavy in proportion to their body weight (more precisely, its mass was considerable if compared to the mass of their body). Their PLSS weighed 26 kilograms (57 pounds) on Earth and 4.3 kilograms (9.5 pounds) on the Moon – one third of their body weight – and therefore displaced their center of gravity upwards and backwards. That’s why they were always leaning forwards: to compensate for the heavy load on their backs.

The video shown in Figure 6.5-1 is often referenced by conspiracy theorists as an example of these unusual maneuvers:

Figure 6.5-1. Astronaut Charlie Duke picks himself up by pushing with this arms after falling forwards on the Moon at 144:35.24 mission elapsed time (Apollo Lunar Surface Journal).


However, Charlie Duke, the Apollo 16 astronaut featured in this video, has explained in his many public talks that the footage actually shows a practical application of the special method that had been devised during simulations on Earth to take advantage of the elastic resistance of the spacesuit to get back up after a fall. During parabolic flights in aircraft which simulated lunar gravity, Duke had found out that two or three “push-ups” were needed to spring back to an upright posture by rotating about his center of gravity.

Moreover, the wire theory fails because the Apollo TV footage includes unbroken sequences that last tens of minutes, during which the astronauts change direction and position repeatedly. How would the wires not get tangled up?

There's also the problem that the TV coverage includes many wide shots, which would require extremely long wires to keep the control rig and winch out of frame.