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Old November 26th 16, 06:55 AM posted to sci.space.policy
Fred J. McCall[_3_]
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Default Using waste for propulsion ?

JF Mezei wrote:

On 2016-11-25 19:32, William Mook wrote:

Propelled by Methane and LOX - that's different than the crew systems being powered by methane. The amount of methane consumed during launch, and boost into Mars transfer trajectory is vastly larger than the amount of methane produced from life support processes.


Launch and escape from earth are not a concern as launch is done with
fuel from ground over many launches to bring fuel up. And escape from
Earth would happen well before the passenger waste would have generated
significant amoumt of methane.

However, the methane generated during the 90 or more days to mars would
help *reduce* amount of fuel needed to get into Mars orbit and then
de-orbit.

If human waste produces methane, does it make sense to use energy to
recycle methane to something else when you can use it almost directly
for engines ?


You can't 'use it almost directly', there's not very much of it, and
whatever mass you don't recycle you have to replace with supplies to
make up for the lost recycled materials. This makes you burn MORE
fuel, not less.

You're stuck on a stupid idea. Get over it.


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