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#26 2005-10-04 09:38:10

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: ION Engines

The ion drive cycler is not fixed, and must obey Newton's laws just the same as everything else. If you were to attach a tether somehow between the fast cycler and slow payload module, winching them together will pull the cycler out of its orbit.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#27 2005-10-04 10:35:19

redhorizons
Banned
From: Oklahoma
Registered: 2005-09-27
Posts: 50

Re: ION Engines

What I meant was.  To have the tether in LEO and as the cycler approached on its return to Mars fling the playload on an intercept course with the cycler.  ????

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#28 2005-10-04 10:58:25

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: ION Engines

Actually you would want the cycler to make its sligh shot manuever around the Earth and as it starts back towards Mars then you would launch the cargo ship from the teher so as to allow it to speed up and catch the cycler as it goes back out towards Mars.
Energy transfer then to the cycler would then keep the combined ship going on its way.

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#29 2005-10-04 11:17:20

redhorizons
Banned
From: Oklahoma
Registered: 2005-09-27
Posts: 50

Re: ION Engines

Cool, that what I was thinking.  Would this not be a fairly inexpensive way of doing this, especially if there was a Space Elevator lifting the cargo into LEO.  The Ion engines should burn for a longitme and be easily serviceable with same approach you would use for getting the cargo to the cycler

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#30 2005-10-04 11:46:29

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: ION Engines

Actually you would want the cycler to make its sligh shot manuever around the Earth and as it starts back towards Mars then you would launch the cargo ship from the teher so as to allow it to speed up and catch the cycler as it goes back out towards Mars.
Energy transfer then to the cycler would then keep the combined ship going on its way.

No. Such a maneuver isn't possible, because the payload won't be going fast enough to dock with the cycler; the cycler will be going very very fast. Faster then even orbital velocity.

And even if it were, why wouldn't you just use the super-tether to just fling the payload directly to Mars?


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#31 2005-10-04 11:58:22

redhorizons
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From: Oklahoma
Registered: 2005-09-27
Posts: 50

Re: ION Engines

What kind of velocity/speed would a tether be capable of?

BTW: Thanks for all the feedback everyone.

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#32 2005-10-04 21:25:11

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: ION Engines

There are two types of tethers possible for launching payloads out of orbit:

-Rotary tether in low orbit

-Space elevator stretched far above geostationary orbit

The biggest limitations on the rotary tether is the difficulty of spinning it up to a high enough speed to be worthwhile: the tether is flexible, so the only way to spin up is to spin the tether station while it is reeled in, then letting it out until reaching maximum velocity. Unfortunatly, I don't think that this method will achieve much, because the maximum rotational RPM is too low.

The second case is to take a space elevator, put a large counterweight at the center, and reel out past geostationary orbit. Here, you would actually experience G-forces away from the Earth due to the centrifugal force exceeding gravity. You could get going quite fast with a long enough "extra" elevator cable if you winched out far enough, perhaps all the way to -1G.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

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#33 2005-10-05 08:52:30

redhorizons
Banned
From: Oklahoma
Registered: 2005-09-27
Posts: 50

Re: ION Engines

So GCNRevenger, are you saying this 2nd method would achieve a high enough velocity to make the application worth while, or would a more conventional propulsion approach be better and just throw out the Kinetic approach and the Ion tug cycler.
And then would using a tether to jettison just cargo containers be more cost efficeint, when you are not concerned about time?  Probably the wrong thread for this discussion, sorry.

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#34 2006-03-08 00:14:34

Yang Liwei Rocket
Member
Registered: 2004-03-03
Posts: 993

Re: ION Engines

Dawn:  To Ceres & Vesta
http://www.newmars.com/forums/viewtopic.php?t=1503
mission shut down, due to budget cutting it never was allowed take-off


'first steps are not for cheap, think about it...
did China build a great Wall in a day ?' ( Y L R newmars forum member )

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