[extropy-chat] FWD [forteana] Re: Are dwarfs betterforlongduration spaceflight?]

Eugen Leitl eugen at leitl.org
Wed Sep 7 13:56:10 UTC 2005


On Wed, Sep 07, 2005 at 06:35:56AM -0700, spike wrote:

> I don't follow your reasoning here.  To have fuel keep
> for seven months, use a little, then keep for another

Wouldn't you want to minimize the transfer time for the
crew module, which asks for a large rocket, if it's a 
chemical drive? If we assemble (dock) and refuel in 
orbit, we can have a pretty large rocket at the
very least in one direction.

I'm assuming we have sent an automatic facility ahead,
which is preparing the fuel, both on ground, and in 
orbit (Phobos/Deimos), verifying it's enough before 
we commit the people.

> two years after that, hydrazine and NOx would be hard
> to beat.  It isn't clear to me how you would store your
> LOX that long, even out there at 1.5 AU.

If we're making LOX/methane on Mars, we'll need a
liquification plant and a cryogenic tank there.
 
> The disadvantage of hydrazine and NOx, the lower
> specific impulse, is compensated by the fact that
> you don't need all that terribly much delta V to
> get out of Mars synchronous orbit to an earthbound
> Hohmann transfer orbit, then you might be able to
> use aerobraking to reenter.

You're not sending much ahead to Mars, are you?

-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a>
______________________________________________________________
ICBM: 48.07100, 11.36820            http://www.leitl.org
8B29F6BE: 099D 78BA 2FD3 B014 B08A  7779 75B0 2443 8B29 F6BE
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20050907/ed0481fa/attachment.bin>


More information about the extropy-chat mailing list