Re: Can a spacewalker even DO a somersault in space?

Very good question Thomas.

If you have unlimited freedom of movement, it's quite possible to orient 
yourself in microgravity without touching anything. During one of the 
Skylab missions, Dr. Owen K. Gariott made a demonstration film showing how 
you can orient your body by moving your arms and legs in various directions 
and patterns. An easy way to do a somersault, for example, is to rotate 
your arms about your shoulders opposite the direction you wish to 
somersault. If you're facing one way and wish to turn 90 degrees to the 
left, you extend your straightened legs out to each side and then "turn" on 
your legs, by now moving them so your left leg is extended forward and your 
right leg is extended behind you. It's a wonderful demonstration of 
conservation of angular momentum.

However, when wearing a spacesuit--especially with a jetpack--your freedom 
of movement is very limited. Besides the bulkiness of the suit itself, you 
also have to contend with its stiffness due to the ballooning effect of it 
being pressurized. While engineers do the best they can to maximize freedom 
of movement in a spacesuit, it is still a very cumbersome and, indeed, 
tiring garment to wear. Motions like I describe above are very difficult if 
 not impossible to perform.

But even if this wasn't the case, it's much safer and much more efficient 
to have a jetpack provide full control of your movement and rotation in all 
directions and all axes. This is epsecially true in emergency situations. 
If you suddenly realized you were about to hit something, it wouldn't be 
very safe to have to first rotate your body away from what you were about 
to hit (where you coudn't see it) and then thrust with the one jet mounted 
on your back. It's much better to keep the object in sight and thrust 
sideways or otherwise correct your trajectory with one of your 24 vernier 
jets.

Hope that gives you some understanding,
-Adams Douglas