Posted on 03/28/2006 12:09:01 PM PST by orionblamblam
Regards,
~dt~
> The reason the shuttle carries a lower payload is because it must *change* it's orbital inclination to reach the 56 degree ISS orbit.
ERRR. WRONG. The Shuttle does not "change" it's orbital inclination to reach ISS; it launches straight to 56 degrees right from the pad. The Shuttle has nowhere near the delta-V capability to do an orbital inclination change of that magnitude while on orbit.
If the Earth did not rotate, then the Shuttle would have exactly the same payload no matter what orbital inclination, or what the launch latitude. it simply would not matter.But the rotation of the Earth provides a boost for low-latitude launch site flying low-inclination orbits. It provides no boost whatsoever to polar launch sites flying polar orbits. it provides a serious *hinderance* to low-latitude launch sites flying west. So far, only one nations - so far as I know - has ever launched satellites ina retrograde (west) orbit... israel. Cuz they don;t have the political option to fly east.
GourmetDan just got confused because this is a topic he knows nothing about.
However, that is for East/West launches. For a North/South launch you can launch from such places as Kodiak Island Alaska.
Ever hear of parallax?
Codswallop! Why do you think we have launch windows?
Also the Earth turns underneath the satellite once it is in orbit. Take a good look at a ground track.
I cannot believe how disingenuous you are being. I showed the actual post where the other poster actually said 'surface-to-space', not 'surface-to-orbit'. How can it be bait-and-switch when he first said "space"?
Because it is still the relative rotation that drives the energy requirements and launching east is like 'taking off into the wind'.
Rotation of what? It has to be the earth rotating.
That last post was from me, I didn't realize my husband was logged on to MY laptop. There will be repercussions...
;-)
>For the same reason that airplanes take off into the wind.
>
>Because it is still the relative rotation that drives the energy requirements and launching east is like 'taking off into the wind'.
Nice to see you finally admit that the Earth's rotation is an important factor in Earth-to-orbit intercepts.
BTW, a fixed coordinate system centered on Earth is NOT the same as a fixed-Earth coordinate system. The latter would be a geocentric model, and it wouldn't work for calculating Earth-to-orbit intercepts, but the former, when allowing the Earth to rotate within the fixed coordinates, in fact is a useful model for such calculations.
Big, big, BIG difference. Huge! Your previous insistence that Earth rotation is not used in such calculations followed by your current attempt to change your position demonstrates your dishonesty in this discussion.
By the way, how did you manage to dig up a real geocentrist? That's the fossil find of the decade!
This one?
It's here: http://www.up-ship.com/Stuff/Humor/humor.htm
> By the way, how did you manage to dig up a real geocentrist?
Disturbingly easy. Dangle geocentrism as "a system that stands in opposition to atheistic science" in front of Creationists, and the geocentrists will start to ooze out of the woodwork. You can also get the hollow-Earthers that way.
Parallax is explained by the stars being centered on the sun, not centered on the earth. The spin of the universe then contains an annual wobble that generates parallax and keeps the gravational forces balanced.
Hmmm... Ummm... Nope!
Am also waiting with great anticipation on your description of how satellite ground tracks are generated. :-)
Big, big, BIG difference. Huge!
Ok, so what is the big, big, BIG, Huge! difference?
Uh-huh, Ummm Yep! (wrt parallax)
And why do you think they (satellite ground tracks) would be generated differently?
Do you mean that you would have to assume that the universe rotated instead of the earth?
Is that the big difference?
When I said 'change' I was speaking of the need for the shuttle to change from it's natural low-inclination orbit to the ISS high-inclination orbit. Not that it needs to change once it gets into orbit.
"For a spacecraft to achieve Earth orbit, it must be launched to an elevation above the Earth's atmosphere and accelerated to orbital velocity. The most energy efficient orbit, that is one that requires the least amount of propellant, is a direct low inclination orbit. To achieve such an orbit, a spacecraft is launched in an eastward direction from a site near the Earth's equator. "
"Launching a spacecraft in a direction other than east, or from a site far from the equator, results in an orbit of higher inclination. High inclination orbits are less able to take advantage of the initial speed provided by the Earth's rotation, thus the launch vehicle must provide a greater part, or all, of the energy required to attain orbital velocity."
This is what the shuttle must do, launch in a direction other than due east, *changing* it's natural orbital inclination. Were the shuttle to launch into its natural low-inclination orbit, it would 'gain more' from the relative rotation than a craft launched from Baikonur, which is further north. It is the need to launch in a direction other than due east to reach the 56 deg inclination that is the key, as Cape Canaveral is further south than Baikonur and therefore gains more from relative rotation, not less. http://www.braeunig.us/space/orbmech.htm
Ummm... No... There is no "natural" orbit inclination. It is inclined or it's not.
Again, how does a rotating universe explain a polar satellite ground track? BTW, ever hear of siderial time -vs- mean solar?
> To achieve such an orbit, a spacecraft is launched in an eastward direction from a site near the Earth's equator. "
Tell me: why east?
> This is what the shuttle must do, launch in a direction other than due east, *changing* it's natural orbital inclination.
With a non-rotating Earth, there is no such "natural orbital inclination." If the Earth did not rotate, it could launch straight north from KSC and be in a polar orbit just as easily as it could launch east, south or west.
> High inclination orbits are less able to take advantage of the initial speed provided by the Earth's rotation, thus the launch vehicle must provide a greater part, or all, of the energy required to attain orbital velocity."
One wonders if you read what you post.
I guess discussing the Coriolis effect would be a lost cause here...
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