Use of carbon monoxide as propellant on Mars

Is it possible to use carbon monoxide as propellant for a rocket?

For example, carbon dioxide from the atmosphere of Mars could be transformed to carbon monoxide and oxygen via photochemical reduction using a photocatalytic process, and unlike the Sabatier reaction (producing methane), precious water is not consumed in the process.

Could the resulting products then be used as a potential bi-propellant?

$$2\,{\rm CO}_2 + 2h\nu\ \to\ 2\,{\rm CO} + {\rm O}_2$$

There may be issues of storage of LOX or LCO, but provided those are addressed somehow, could a rocket engine or thruster use these effectively?

• en.wikipedia.org/wiki/Photochemical_carbon_dioxide_reduction – Antonio Cipolla Apr 23 '17 at 10:00
• This is a pretty interesting question actually! Split one oxygen from CO2 and you still have a gas (two in fact!), but split both and all you've got is a lump of coal unless you want to start spending your water. Could come in handy for some local applications, atmospheric recon craft for example. – uhoh Apr 23 '17 at 12:26
• As other gases, carbon monoxide could be liquified by low temperature. LCO (-191.5 °C) is colder than LOX (-183 °C) but not so cold as LH2 (-252°C) We should compare the specific impulse of this propellant with other combinations. – Uwe Apr 23 '17 at 14:00
• carbon monoxide is a less efficient combustible than methane but apparently will be cheaper to product on Mars – Antonio Cipolla Apr 23 '17 at 14:02
• Here are two papers from NASA about this propellant combination: ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19960045922.pdf ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19910014990.pdf – Uwe Apr 23 '17 at 14:23

1 Answer

Yes, it could be. The ISP for CO/ O2 is about 200. Compare that to Methane, with a specific impulse of 299, and you can see it's really not that great.

Of some related interest is a hot Carbon Dioxide rocket, with a theoretical ISP of about 260. This would work for short surface to surface hops, but not beyond orbit.