A manned maneuvering unit (MMU)
is a one man rocket powered backpack that is used in space since the US
space shuttle missions. The concept was developed much earlier in the
mid 1960's. In space MMUs allow the astronaut to operate away from the
spacecraft untethered. On earth those unit are usually just called
jetpacks and if you are old enough to remember the opening ceremony of
1984 Olympic games in Los Angeles,you will know what I'm talking about.
If not this link will help you visualize what happend then. MMUs where
also used by the Sowjet space program.
The big advantage of MMUs is the great maneuvering flexibility in space
and on earth. One big disadvantage on earth is the very limited flying
time the jetpack delivers as onboard fuel is limited. If more flying
time could be achived, it would be the ideal transport vehicle for
everyday activities. Recently a similar idea has been taking to the
extreme as you can see in this video.
As many of us think the idea of a manned maneuvering unit is something
new, I believe similar technology was used by the "gods" in antiquity.
Ancient Indian stele (see my photo examples from the British Museum in
London below) show a curious similarity between the ancient stele and
The USSR version of an American MMU (see below)
we can look at the above stele from the front (left photo). You can
clearly see that the Indian god/godess is depicted with four arms. The
comparison shot with the US MMU on the right. Can you see why the
ancient artists where confused because they never seen anything
technical before? It really looks like the Astronaut has four arms if
you don't know what your are looking at.
If you scroll further down on the page you can see the same effect on
simpler MMU that was used on Earth without the spacesuit. The exhaust
on both sides of the unit also looks like the person has four arms if
you see it from far away and you don't know what it is.
Man beachte, dass bei dieser
Darstellung die Beine der Gottheit regelrecht "festgeschnallt" sind.
Bei modernen Piloten macht man das wegen der hohen
Wurde die Antike MMU auch in der Atmosphaere benutzt? If you look
closely you will see that the legs of the god are fastened with a
safety belt. With modern pilots this is done because of the high
g-forces during acceleration and banking.
Image courtesy of: NASA
Another intersting aspect are the many tools the
MMU has onboard like the camera. For somebody completely without any
technical knowledge those might be interpreted as an eye. Other
powertools that move by themself must appear magical to somebody
without technical background. Could it be that powertoolols would be
depicted as "little helpers"? Afterall there must be a little person in
them to make them work. I think this is exactly what we see on the
ancient stele on the left.
Here another example of a "MMU stele" to show that the above is not
just a single case.
Below you can see an example of a Jetpack as it is
used for flights inside the atmosphere.
Quelle der Photos:
Image courtesty: see below
If you want to know more about MMUs, I recommend