Author Topic: ITS Environmental Control and Life Support System (ECLSS)  (Read 29277 times)

Offline Slarty1080

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #60 on: 03/22/2018 06:07 pm »
You can view the thesis here
I reject your conclusions, and can prove it with this 5 minute google and ebay search I did!
More seriously, downloaded, and glad to find that it's not in a language I don't speak. (German).
On skimming I find it's not really amenable to skimming, and I'm going to have to read it more in depth.
Thanks again!



Although we must remember that this thesis was written with the original ITS (pre 2017) in mind,
a lot of the analysis is still valid and many of the points made still stand. Anyone interested in BFS ECLSS should read this.

Just a few point to note

High closure ECLSS require high complexity and high power.
Open or low closure ECLSS are low complexity and low power, but require high mass and volume.
ECLSS is composed of many different sub systems each of which scales differently and each of which has multiple technology options available in different states of technical Readiness. This thesis focuses on higher technical readiness technologies.

Another key point made was it would be better to have 99.9% reliability and 90% recycle closure than 90% reliability and 99.9% closure.

It would appear that a 100 man mission is entirely possible based on the extensive requirements drawn up in this document provided some additional power could be supplied.

The thesis considers a crew size of 12, 40 or 100 with mission durations of 88 and 210 days.

As well as examining the technological options in great detail it also considers issues such as potential deck layouts and shift patterns and their impact on ECLSS.



IMHO any ECLSS will evolve with BFS, will increase in ability as time goes on, will be modular and scalable for a considerable time after the first manned landings. I doubt that 100 people will ever actualy  be transported in the lifetime of the BFS, in part because of the need to carry a lot of additional equipment and infrastructure for the new colonists. With 100 colonists there would be no room for anything else.



My optimistic hope is that it will become cool to really think about things... rather than just doing reactive bullsh*t based on no knowledge (Brian Cox)

Offline MP99

Sorry to drag up a comment from a year ago...

For an open food system, would this result in CH4 (like ISS), and O2? If these could be liquefied, how much additional propellant could be produced over a single trip?

Thanks, Martin

Offline speedevil

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #62 on: 07/06/2018 01:36 pm »
Sorry to drag up a comment from a year ago...

For an open food system, would this result in CH4 (like ISS), and O2? If these could be liquefied, how much additional propellant could be produced over a single trip?
'No' - you need extra systems, the amount of methane emitted by a human is small, and even optimally ignoring things, it is unlikely to help.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4909143/ indicates it's in PPM levels in breath, so tens of milligrams a day, with flatulance being similar.
This paper gives on page 5, 10000 people-days of excrement as 76kg of methane.
This is about the right number of people-days for a 100 person crew, and neglects the need for additional low carbon biomass to add to the reactor.

76kg of methane is wholly negligible compared to the mass of what you'd need to convert it, even without the additional biomass.
In principle, if your CO2->fuel process is sufficiently lightweight, you could run it intermittently and regenerate some 10kg of fuel from exhaled CO2/H2O. (100W*100 days*100/ 44MJ/kg)*0.5 efficiency.

Again pretty much negligible.

Tags: ITS ECLSS 
 

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