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#1 2007-11-29 09:49:13

Terraformer
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From: The Fortunate Isles
Registered: 2007-08-27
Posts: 3,909
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Re: Mass Drivers

This is about using mass drivers to launch stuff.


Use what is abundant and build to last

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#2 2007-11-29 10:02:11

cIclops
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Registered: 2005-06-16
Posts: 3,230

Re: Mass Drivers


[color=darkred]Let's go to Mars and far beyond -  triple NASA's budget ![/color] [url=irc://freenode#space]  #space channel !! [/url] [url=http://www.youtube.com/user/c1cl0ps]   - videos !!![/url]

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#3 2007-11-29 10:12:27

Terraformer
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From: The Fortunate Isles
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Re: Mass Drivers

Those others are all dead and off the first page so I didn't notice them.


Use what is abundant and build to last

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#4 2007-11-29 13:41:38

John Creighton
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From: Nova Scotia, Canada
Registered: 2001-09-04
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Re: Mass Drivers

Anyway, someone in another thread mentioned 1 km as the largest conservable radius of a mass driver. The cost of such a device should beyond practical but if such a device could be built out of rigid materials then as the thing starts to pick up speed a tether could extend the radius further. I think that a tether could extended the radius 10 times beyond the length of the rigid part of the arm. Also as mentioned in another thread, even at 10 km we are still talking 100 gees.
http://www.newmars.com/forums/viewtopic … 6&start=40

I can’t imagine the friction forces and the effect such a device would have on local wind patterns. I think that linear acceleration would make more sense as an alternative to a first state. I haven’t worked out though how long a track you would need to get a reasonable boost at 9 gees of acceleration. Maybe I’ll work it out tonight.


Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]

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#5 2007-12-01 00:16:28

John Creighton
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From: Nova Scotia, Canada
Registered: 2001-09-04
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Re: Mass Drivers

I'm not sure if anyone is interested but:

orbinal velocity7.8 km/s = 7800 m/s

A=dv/dt=dv/dx dx/dt=dv/dx v
a dx=v dv
a delta X = ½ (V2^2-V1^2)
delta X = ½ (V^2)/a=0.5*(7800^2/(9.80665*10))
=310197.67198788577138982221247827 m
=310 km

Thus forgetting engineering problems like friction energy stability and such you would need a 310 km track to accelerate something to orbital velocity if you are accelerating at 10 gees. Perhaps  100 km would be enough to replace a first stage but it is apparent that any kind of flinging device is going to be massive and very expensive if the G forces are not too excessive.

http://en.wikipedia.org/wiki/Gravitational_acceleration
http://en.wikipedia.org/wiki/Orbital_speed
http://www.onlineconversion.com/speed_common.htm


Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]

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#6 2007-12-01 07:37:49

cIclops
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Registered: 2005-06-16
Posts: 3,230

Re: Mass Drivers

All this and much more has been discussed here previously, please try to find and add to existing topics. There are plenty of interesting ideas and excellent comments available. It's perfectly ok to bring dead topics back to life!

Earth to LEO - discuss

Un- conventional ways to LEO


[color=darkred]Let's go to Mars and far beyond -  triple NASA's budget ![/color] [url=irc://freenode#space]  #space channel !! [/url] [url=http://www.youtube.com/user/c1cl0ps]   - videos !!![/url]

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#7 2007-12-01 16:46:07

John Creighton
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From: Nova Scotia, Canada
Registered: 2001-09-04
Posts: 2,401
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Re: Mass Drivers

All this and much more has been discussed here previously, please try to find and add to existing topics. There are plenty of interesting ideas and excellent comments available. It's perfectly ok to bring dead topics back to life!

Earth to LEO - discuss

Un- conventional ways to LEO

I'm sure it's been discussed there but I didn't notice it skimming though it. I prefer focused topics. The topics you listed are general.


Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]

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#8 2007-12-01 17:03:01

cIclops
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Registered: 2005-06-16
Posts: 3,230

Re: Mass Drivers

Hopefully when the board is updated these topics can be better focused. At the moment it's not possible to combine topics or copy messages to other ones. There's a lot of fascinating discussion spread all over the board, it's so easy to miss the best comments.


[color=darkred]Let's go to Mars and far beyond -  triple NASA's budget ![/color] [url=irc://freenode#space]  #space channel !! [/url] [url=http://www.youtube.com/user/c1cl0ps]   - videos !!![/url]

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