G-force measurement

1. Mar 21, 2009

Sword7

Hello folks,

Does anyone know any formula about g-force measurement when launching into orbit? For example, 1 G at ground, 3-5 G during launching, 0 G at orbit.

Thanks,
Tim

2. Mar 21, 2009

fluidistic

Hi,
I don't think there's a general formula. For example it could be say "500 G" for a little time (launching time) and then you could put the satellite into orbit.
It could also be accelerated very slowly, so G wouldn't get higher than "2 G" during its trip from Earth's ground to Earth's orbit.
But in any case you need to accelerate the satellite more than g (that is, around 9.8m/s^2).

3. Mar 21, 2009

pixel01

One G equals to 9.8m/s2. You have 1 G at the surface of the Earth as well. So before launching, the g-force is 1 G (just like you and me have). At the launch, if the acceleration is ~20m/s2 so the astronauts bear about 3 G , and so on. In orbit, the g-force is almost zero and you have O G.

4. Mar 22, 2009

fluidistic

Are you sure pixel, that if the acceleration is about 20m/s^2 then the astronauts bears 3 G?
I wouldn't say so. For me it's about 2 G. Even if the force required to do so has to "cancel out" the "1 G" acceleration we feel on Earth's ground and then has to propulse the astronauts to an acceleration of 20 m/s^2.

5. Mar 22, 2009

D H

Staff Emeritus
Pixel is correct. Relative to a free-falling reference frame, that rocket is accelerating upward at about 30 m/s^2, not 20.

6. Mar 22, 2009

fluidistic

Ok then I'm wrong.
I get it now!

7. Mar 22, 2009

Sword7

Hello folks,

I found equation for g-force when I searched through google. Look at http://en.wikipedia.org/wiki/G-force" [Broken] about equation of g-force for calculation.

Tim

Last edited by a moderator: May 4, 2017