Monday, February 24, 2014

Can you stop a space craft on a dime?   

How about a 747 jetliner?   


For a 747 airliner or a space craft, stopping on a dime is a physically impossible thing to do.  Let’s see why that is.

What if I asked you to fly your 747 jetliner to a destination runway somewhere; and let’s say that I mark an X on the runway and I tell you to stop your 747 on that X.  How would you accomplish that?  

Could you touch down on that X, and immediately stop on it?…; no, of course not; in order to have your 747 stand still on that X, you would have to have been decelerating before the X, and then you would have to either land way before the X and brake and reverse-thrust until you slowed down enough to gently come to a stop on that X; or you could touch down on the X, then brake and reverse-thrust as you go down the runway and as you come to a stop either turn around and come back or put it in reverse and back it up to the X.  True?...

Ok, now let’s talk about the process of launching and “parking” a geostationary satellite.  

First, we have to assume that we do in fact have these satellites hovering, “fixed”, (relative to the earth), above the earth’s equator.  My question is, How do they take a speeding space craft, as the launch data indicates, and “park” it without “braking” and/or reverse-thrusting?  I would really like to understand this. 

Remember, relative to the earth, that satellite is “parked”.  And may I remind you that the craft approaches with speed, and according to the launch data, increases in speed in order to “park” that satellite; how do they manage that? 

This is not a snarky rhetorical question.  I really don’t understand how to reconcile the space craft’s approach speed and subsequent increase in speed with a “parked” satellite position.  There’s no mention in the launch data about any “reverse-thrusting” or “braking” to bring it to a stop, as is necessary in my 747 example.  <<CLICK HERE>> for article with geostationary launch data

Let me mention here that there is a slowing down of the space craft as it approaches the geostationary altitude due to the earth’s gravitational pull, but then the data says, they increase the speed of the space craft at the geostationary altitude, (“parking” altitude) to match the rotational speed of the earth; which at that point is just under 7000mph.

Once again, I'd like to remind you that the geostationary "parking spot" is standing still, relative to the earth.  So the pivotal question is: does the earth rotate INDEPENDANTLY of the the space craft when it gets above the earths atmosphere?... The answer is:  NO!... See:  <<CLICK HERE>> Can you accelerate into a GEO SAT “parking” spot?

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