Author Topic: "Model" rocket hits 121,000 feet  (Read 806 times)

Offline PFactorDave

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Re: "Model" rocket hits 121,000 feet
« Reply #15 on: October 20, 2011, 11:17:00 AM »
That is just under 23 miles up. What is the minimum height for low earth orbit? Just curious.

I believe low Earth orbit is anythin from about 100 miles ups to about 1200 miles or so, if my memory serves (which it sometimes does not).

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Offline clerick

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Re: "Model" rocket hits 121,000 feet
« Reply #16 on: October 20, 2011, 11:19:21 AM »
I believe low Earth orbit is anythin from about 100 miles ups to about 1200 miles or so, if my memory serves (which it sometimes does not).

correct

Offline Maverick

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Re: "Model" rocket hits 121,000 feet
« Reply #17 on: October 20, 2011, 11:25:10 AM »
Thanks. Those folks have a pretty darn decent start on it then. Of course IIRC escape velocity is something like 17k MPH too.
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Offline clerick

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Re: "Model" rocket hits 121,000 feet
« Reply #18 on: October 20, 2011, 12:22:50 PM »
Thanks. Those folks have a pretty darn decent start on it then. Of course IIRC escape velocity is something like 17k MPH too.

Escape and orbit velocities both depend on the "height" you want to reach but, don't confuse them, they are not the same thing.

Offline chaser

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Re: "Model" rocket hits 121,000 feet
« Reply #19 on: October 20, 2011, 02:30:35 PM »
Thanks. Those folks have a pretty darn decent start on it then. Of course IIRC escape velocity is something like 17k MPH too.

http://www.physlink.com/Education/AskExperts/ae158.cfm

This link explains escape velocity. for Earth its about 25,000 MPH. Thats with no propellant though, meaning if an object was placed on the surface of the earth and thrown straight up at 25,000 mph it would escape the gravity of Earth with nothing continuing to propel it, it cold escape with just the velocity in initially had.


I'm not sure about a propelled rocket though. I guess as long as you have more thrust than weight and plenty of fuel (fuel seems to be the biggest factor. Run out of fuel before you escape and you aren't going anywhere) you can escape at any speed. <--- completely uneducated guess and probably wrong.