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Author Topic: Burning Up in the Atmosphere  (Read 9839 times)

Offline Xin

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Burning Up in the Atmosphere
« on: 14/03/2006 02:39:59 »
What exactly causes objects to burn up in our atmosphere? Is it simply friction, and that faster moving objects get hotter quicker? Or does the atmosphere function like a sort of magnifying glass and causes the sun's ray to superheat? I never hear of rockets leaving the Earth's atmosphere experiencing any sort of "burn" as they enter space...but perhaps I'm not educated enough :)

Is it possible to ascend to Earth from space in a way that won't cause a "burn out" entering the atmosphere? Is it possible to extend a pole, wire, string, etc from the Earth and attach it to the Space Station or something else out in orbit?

I know I'm asking a lot of questions...just not having much luck finding any useful answers via Google and the curiousity is haunting me.


 

Offline ukmicky

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Re: Burning Up in the Atmosphere
« Reply #1 on: 14/03/2006 03:33:11 »
quote:
Originally posted by Xin

What exactly causes objects to burn up in our atmosphere? Is it simply friction, and that faster moving objects get hotter quicker? Or does the atmosphere function like a sort of magnifying glass and causes the sun's ray to superheat? I never hear of rockets leaving the Earth's atmosphere experiencing any sort of "burn" as they enter space...but perhaps I'm not educated enough :)
yes its friction,atmospheric friction.Also before rockets leave our atmosphere and enter space they do heat up due to the speed at which their travelling through the air (drag) but not as much as they do when re-entering .

 
quote:
Is it possible to ascend to Earth from space in a way that won't cause a "burn out" entering the atmosphere? Is it possible to extend a pole, wire, string, etc from the Earth and attach it to the Space Station or something else out in orbit?
Now where did i put my fishing rod, I'll get back to you:)



Michael
« Last Edit: 14/03/2006 03:34:41 by ukmicky »
 

another_someone

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Re: Burning Up in the Atmosphere
« Reply #2 on: 14/03/2006 04:02:24 »
quote:
Originally posted by Xin

What exactly causes objects to burn up in our atmosphere? Is it simply friction, and that faster moving objects get hotter quicker? Or does the atmosphere function like a sort of magnifying glass and causes the sun's ray to superheat? I never hear of rockets leaving the Earth's atmosphere experiencing any sort of "burn" as they enter space...but perhaps I'm not educated enough :)

Is it possible to ascend to Earth from space in a way that won't cause a "burn out" entering the atmosphere? Is it possible to extend a pole, wire, string, etc from the Earth and attach it to the Space Station or something else out in orbit?

I know I'm asking a lot of questions...just not having much luck finding any useful answers via Google and the curiousity is haunting me.



It is, as you speculate, merely friction.

The reason why you don't hear of the problem at lift off is because the problem occurs because the objects re-entering the Earth's atmosphere are in freefall, whereas on lift-off, they are being fighting against the Earth's gravity rather than being drawn down by it, and so don't gain the same speeds.

Heating effects do, to a limited extent, effect supersonic, and to a greater extent, hypersonic aircraft.  The skin temperature on Concorde was over 100 degrees C (one quote is 127 C, which was 180 C  above the ambient outside air temperature).

http://www.sr-71.org/blackbird/sr-71/
quote:

The airframe of the SR-71 is very unique. To withstand the friction-generated heat at Mach 3+, over 90 percent of the airframe is made of titanium composite. Also to withstand heat, the main gear tires have been impregnated with aluminum and are filled with nitrogen.



http://en.wikipedia.org/wiki/Heat_shield
quote:

An approximate rule-of-thumb used by heat shield designers for estimating peak shock layer temperature is to assume the air temperature in kelvins to be equal to the entry speed in meters per second. For example, a spacecraft entering the atmosphere at 7.8 km/s would experience a peak shock layer temperature of 7800 K. This method of estimation is a mathematical accident and a consequence of peak heat flux for terrestrial entry typically occurring around 60 km altitude.



http://en.wikipedia.org/wiki/SR-71_Blackbird
quote:

Due to the great temperature changes in flight, the fuselage panels did not fit perfectly on the ground and were essentially loose. Proper alignment was only achieved when the airframe warmed up due to the air resistance at high speeds, causing the airframe to expand several inches. Because of this, and the lack of a fuel sealing system that could handle the extreme temperatures, the aircraft would leak its JP-7 jet fuel onto the runway before it took off. The aircraft would quickly make a short sprint, meant to warm up the airframe, and was then air-to-air refueled before departing on its mission. Cooling was carried out by cycling fuel behind the titanium surfaces at the front of the wings (chines). Nonetheless, once the plane landed no one could approach it for some time as its canopy was still hotter than 300 degrees Celsius. Non-fibrous asbestos was also used, as in non-ceramic automotive brakes, due to its high heat tolerance.





George
 

ROBERT

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Re: Burning Up in the Atmosphere
« Reply #3 on: 14/03/2006 10:32:43 »
quote:
Originally posted by Xin


Is it possible to extend a pole, wire, string, etc from the Earth and attach it to the Space Station or something else out in orbit?



Hi Xin,
I think you are referring to a construction called a space elevator:-

" A space elevator is a hypothetical structure designed to transport material from a planet's surface into space. Many different types of space elevator structures have been proposed. They all share the goal of replacing rocket propulsion with the traversal of a fixed structure via a mechanism not unlike an elevator, hence its name, in order to move material into or beyond orbit. Space elevators have also sometimes been referred to as beanstalks, space bridges, space lifts, space ladders or orbital towers.

The most common proposal is a tether, usually in the form of a cable or ribbon, that spans from the surface to a point beyond geosynchronous orbit. As the planet rotates, the inertia at the end of the tether counteracts gravity and keeps the tether taut. Vehicles can then climb the tether and escape the planet's gravity without the use of rockets. Such a structure could eventually permit delivery of great quantities of cargo and people to orbit, and at costs only a fraction of those associated with current means.".
http://en.wikipedia.org/wiki/Space_elevator


« Last Edit: 14/03/2006 10:35:12 by ROBERT »
 

Offline Hadrian

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Re: Burning Up in the Atmosphere
« Reply #4 on: 14/03/2006 10:56:58 »
This all brings being stuck in the elevator to new heights. I wonder waht sort of music they will use. Maybe it will be a new jonra "space elevator music"



What you do speaks so loudly that I cannot hear what you say.
 

ROBERT

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Re: Burning Up in the Atmosphere
« Reply #5 on: 14/03/2006 11:37:39 »
quote:
Originally posted by Hadrian

 I wonder what sort of music they will use. Maybe it will be a new genre "space elevator music"



SPACE ELEVATOR MUSIC TITLES:-

"Stairway to Heaven"
http://www.brave.com/bo/lyrics/stairhea.htm

"Puppet on a string"
http://www.seeklyrics.com/lyrics/Elvis-Presley/Puppet-on-a-String.html

"up up and away"
http://www.stlyrics.com/lyrics/bridgetjonessdiary/upupandaway.htm
« Last Edit: 14/03/2006 11:49:50 by ROBERT »
 

Offline Hadrian

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Re: Burning Up in the Atmosphere
« Reply #6 on: 14/03/2006 13:26:12 »
Very elevating choices ROBERT.

What you do speaks so loudly that I cannot hear what you say.
 

Offline Xin

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Re: Burning Up in the Atmosphere
« Reply #7 on: 14/03/2006 18:10:35 »
Haha...very nice. Thanks guys :)
 

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Re: Burning Up in the Atmosphere
« Reply #7 on: 14/03/2006 18:10:35 »

 

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