[extropy-chat] MARS: Because it is hard

[Dan Clemmensen]

Eugen Leitl wrote:

>On Tue, Apr 13, 2004 at 01:53:31PM +0930, Emlyn ORegan wrote:
>
>  
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>>It sounds as though it could be intelligent to use both our moon and a
>>Mars moon. Set up our moon as a general staging area for anything off
>>earth, put a mission together to go from their to Mars via a base on a
>>Mars satellite. Is their some radically different form of propulsion
>>that could be used to go moon-to-moon, where the transport craft isn't
>>designed to go near a serious gravity well?
>>    
>>
>
>Yes. A linear motor on Luna surface can throw cargo into lunar orbit, you can
>go with electric propulsion to Mars, (aero)brake there, and land on the moons
>also with electric propulsion alone.
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Now all you need is a way to land on the moon without using fuel you 
must carry.
Since it's a vacuum, It is theoretically possible to reverse the linear 
motor. Of course,
I don't want to be too close to the thing when they test it...  
Basically, you use an
ion drive to lower the orbit to nearly ground level, and then make sure 
you don't miss
the mouth of the linear motor. The motor decelerates you from ELLO 
(Extremely low
Lunar Orbit) to zero over a 100Km track. Using regenerative braking, you 
could launch
an outbound capsule on a separate track as you landed an inbound capsule.

Spike: how fast is ELLO? Surely 100KM is long enough to stay below 1G?