Undergrad Running on the Space Station compared with running on Earth

[sophiecentaur]

Neglecting air resistance, you have to keep your feet under your center of gravity.

I imagine that sort of skill is easy enough to acquire if you already have the Right Stuff. I quite recently used a treadmill for the first time (on Earth) and I had to hang on for a while before being sure of myself.

 

[jbriggs444]

I imagine that sort of skill is easy enough to acquire if you already have the Right Stuff. I quite recently used a treadmill for the first time (on Earth) and I had to hang on for a while before being sure of myself.

My brother, my sister and myself were allowed to play pretty much as we saw fit in the backyard using an array of stuff such as horizontal ladders, ropes, swings, spools, barrels, crates and tall trees. My parents believed, correctly, that we were aware of our limitations. One evening my dad had a bunch of twelve year olds over from the school where he worked. He had to put away the rope swing because we (several years younger than they) were all performing stunts too dangerous for them to safely imitate.

Sadly, age steals youthful competence.

 

[256bits]

On Earth, that is certainly so. Neglecting air resistance, you have to keep your feet under your center of gravity.

On a treadmill in space, you need to arrange for your contact force to be on a line that intersects with the anchor for the straps. Instead of moving the contact point relative to the center of gravity, you'll want to move the contact point relative to the strap anchor.

It would/should be possible to simulate running uphill / downhill on the space treadmill by the angle of lean of the anchor strap.
Something not possible on Earth except by raising or lowering the bed ( or perhaps that could be done with a horizontal tether attached to your hips attached to the front or rear of the machine depending ).
Something I was to expand on in my previous post.
Apologies to @Grinkle for being too terse and certainly not explanatory.

 

[sophiecentaur]

Sadly, age steals youthful competence.

The worst thing is the memory. You can work around lack of strength and agility by taking your time but . . . now where was I??

 

[A.T.]

Fun side note: There is also the exact opposite of the NASA treadmill, one that reduces the effective weight.

 

[Grinkle]

It would/should be possible to simulate running uphill / downhill on the space treadmill by the angle of lean of the anchor strap.

I see. That's interesting - one can make the force vector inclinations with respect to the plane of the running surface match pretty well I would think (gravity vs elastic force). One is going to be 'slammed' a bit with each stride as the bands contract. On earth, one stores up potential energy running up a hill, or one decreases the amount of work the treadmill motor does running on an upwardly inclined belt surface. In space, the elastic will return the non-normal component of the power expended in each stride as it pulls the runner back towards the running surface. The more incline, I believe, the more the difference between the variable spring force and the constant gravity force will be noticed by the runner.

Edit: I was only pondering the uphill case. I don't think changing the angle in the 'backwards' direction to simulate downhill running would work very well.