Could they use methane as fuel?

[jinglesassy]

hello, i thought of a methane engine for ascent from mars and you get the fuel from the poop instead of dumping it overboard store it to harvest methane from it would help with weight but would it be feasible?

 

[Ghostrider]

You'd need a lot of crap for this...

 

[jinglesassy]

yeah for the 18 months u will be on the surface of mars you will get alot of crap to use for the ascent

 

[Wolfer]

I know the Mars Direct plan proposes to make methane and oxygen, with the CO2 in the atmosphere of Mars and some hydrogen carried along, to be used for the return trip. It seems to me that the poop would be better used as fertilizer for a small farm.

 

[Zatnikitelman]

Hydrogen could be extracted from the water ice, then again, if you have water, you could use the more efficient LOX/LH2.

 

[Urwumpe]

hello, i thought of a methane engine for ascent from mars and you get the fuel from the poop instead of dumping it overboard store it to harvest methane from it would help with weight but would it be feasible?

Sure... methane is just another hydrocarbon...

 

[T.Neo]

Methane/LOX can be made from the native Martian atmosphere and a feedstock.

As organic material is very valuable outside Earth, it is best to conserve it for recycling within the ship's life support.

 

[Eagle]

I suppose the question is how many kg of methane can be produced each month from a crew's waste? (assuming no recycling is done)

I haven't done any research but I'm guessing (so disregard what I'm about to say) its only a few tones which will likely leave you short of the fuel you need by an order of magnitude.

 

[n72.75]

Yes, they can.

 

[Bj]

Yes, they can.

I wonder if burning like that smells...

 

[n72.75]

I wonder if burning like that smells...

"methane is a colorless, odorless gas"

http://en.wikipedia.org/wiki/Methane

 

[jinglesassy]

has there ever been a test to see how much methane a turd puts out in a month?

 

[Brycesv1]

it depends on what organic material is in the aforementioned turd. All turds are not created equal.

 

[Andy44]

According to this article:

http://extension.missouri.edu/publications/DisplayPub.aspx?P=G1881

A pig produces about 4.1 cubic feet of methane per day, and a pig is about the size of a human. Domestic pigs have a different diet, of course, but this gives you a ballpark figure.

I can't find a link to a source for humans.

 

[Bj]

I can't find a link to a source for humans.

Not much of a source but related...

[ame="http://www.youtube.com/watch?v=RHcDP_Yew-g"]YouTube- MythBusters - Do Pretty Girls Fart?[/ame]

 

[Eagle]

According to this article:

http://extension.missouri.edu/publications/DisplayPub.aspx?P=G1881

A pig produces about 4.1 cubic feet of methane per day, and a pig is about the size of a human. Domestic pigs have a different diet, of course, but this gives you a ballpark figure.

Decided to do the math.
4.1 ft^3 * 0.717 kg / m^3= 8.324 * 10^-2 kg

Assuming 10 space-pig crew on a 90 day surface stay = 900 pig*days

Which gives us 74.9 kg. Not nearly enough.

 

[joey1405]

Decided to do the math.
4.1 ft^3 * 0.717 kg / m^3= 8.324 * 10^-2 kg

Assuming 10 space-pig crew on a 90 day surface stay = 900 pig*days

Which gives us 74.9 kg. Not nearly enough.

Although it may not be enough, it could still cut back on weight, if there was an efficient enough way to do so.

 

[Dig Gil]

It would be way more efficient if you could control the 'storage' environment's temperature, humidity and microbial fauna.