g forces (1 Viewer)

[moo_moo_molly]

Hello,
I don't really understand how facing up both during launch and re-rentry means that the astronaut will experience an 'eyeballs-in' g load... so feel free to explain

 

[sinist4]

yep^ i no wat ur talking bout, i mean it seems normal to face up on launch so the eyeballs go towards the body, but if they did that on re-entry wouldnt it go out wards.

i hav the same problem in trying to understand how that works...
sorri cant help ya there

 

[alcalder]

OK on reentry, they are falling towards the earth at great speed. The Earth's atmosphere is slowing them down. It is like sitting in a car that is going at great speed and then suddenly shoving on the brake. If you were facing foward (and not wearing your seat belt) you'd be catapulted into the windscreen. BUT, if you were facing the back of the car, when the car braked, you would be pushed into your seat and your eye-balls would be pushed back into your head.

Does that help??

 

[JBakaka]

that makes sense but do they face the earth on re-entry or do they face "upwards" ie towards space?

 

[mitsui]

i thot they re-entry backwards, so "lying down and face up in both take off and re-entry"?? =@

 

[Testpilot]

that makes sense but do they face the earth on re-entry or do they face "upwards" ie towards space?

Because the g forces on them push them into their seats, therefore pushing "eyes in" in positive Gs. To continue with the car analogy, when you accelerate violently, what direction are you pushed in? Your pushed back into your seat. Now imagine the car is driving veritcally.

The astronauts face 'up' while lying on their back in the spaceship because humans are better able to handle G forces in the x and z axis (where y is head-toes) hence if sitting on launch it would be positive Gs in y axis.