Author Topic: ITS Environmental Control and Life Support System (ECLSS)  (Read 9089 times)

Offline sghill

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Despite Elonís assertion that the ride on the ITS will "be, like, really fun to go," living aboard the vehicle will be dangerous and decidedly not fun if the types of ECLSS we use on board the space station are utilized on ITS.

Supporting 100 people for months in zero-g requires new systems and techniques.  100 bored passengers needing to eat, poop, and clean themselves are going to be a mess.

IMHO, the basic problem of no up and down in a weightless living environment needs to be addressed. 100 people canít have non-flushing toilets, no ability to move fluids down a drain, and no ability to cook for dozens several times a day.  OK, cooking isnít so important, but the space shuttle used to return after two weeks with seven people on board with filth everywhere- and on every possible surface. Space shuttle also dumped its fluids. ITS needs a recycling system and holding tanks 10 times the size of the one on ISS. I donít see these elements in ITS renderings.

Furthermore, the situation is further complicated because whatever system they come up with must function properly in both weightlessness and in Mars gravity. It also must be simple enough to avoid a catastrophic failure and be repaired during a flight. In other words, they need simple toilets, a functioning galley, and a septic system that operate in both environments.

So how is this accomplished, what will SpaceX's ECLSS look like, and how do we fill in the blank areas in the rendering below with realistic support systems?

[On a personal note, Iíd like to think Elonís upcoming reveal is that theyíll use a tether system to generate low gravity between two ITS ships traveling back and forth to Mars. It makes the above challenges easier IMHO.]
« Last Edit: 05/11/2017 01:46 PM by sghill »
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Offline jpo234

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #1 on: 05/11/2017 02:37 PM »
Supporting 100 people for months in zero-g requires new systems and techniques.  100 bored passengers needing to eat, poop, and clean themselves are going to be a mess.

I don't think that this is a high priority item for SpaceX. Initially we will mostly see unmanned freighters and manned ships with a relatively small exploration crew (less than 20, I assume). That's based on Paul Woosters recent presentation were he said: "We have a lot of margin for early missions, which is quite helpful.". "a lot of margin" IMHO precludes 100 passengers.

So, an ECLSS for 100 passengers is something that will need to happen after the "early missions". When do the early missions end? My guess is at least 20 years after the first one. At that point SpaceX could be well on its way to the ships that make the initial ITS "look like a rowboat". So, trying to fit an ECLSS for 100 passengers into the initial ITS version is something that might never happen.
« Last Edit: 05/11/2017 02:45 PM by jpo234 »

Offline redliox

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #2 on: 05/11/2017 03:10 PM »
Supporting 100 people for months in zero-g requires new systems and techniques.  100 bored passengers needing to eat, poop, and clean themselves are going to be a mess.

I don't think that this is a high priority item for SpaceX. Initially we will mostly see unmanned freighters and manned ships with a relatively small exploration crew (less than 20, I assume). That's based on Paul Woosters recent presentation were he said: "We have a lot of margin for early missions, which is quite helpful.". "a lot of margin" IMHO precludes 100 passengers.

Right - it's going to be a while yet before we see 100-person crews.  It is indeed going to be a massive pain supporting 100 people for 6-month-some voyagers...but developing an ECLSS precursor that can handle something in the 5-20 person range ought to be possible and also possible to incrementally refine.  It will likely take a combination of NASA input and SpaceX's 'aggressive persistence' to go from 5 to finally 100.

In the meantime, I've heard water recycling is approaching 100% although I doubt it has the capacity to handle 100 people, and oxygen recycling is something like 50% (probably varies depending on what system utilized).  The practice between the STS and ISS seems to be paying off, and even without artificial gravity I believe we could handle a trip to Mars now with the following guidelines:

-Crew of less than 10
-Keep the inbound/outbound trips under 9 months
-Habitat with supplies awaiting at Mars
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Offline RonM

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #3 on: 05/11/2017 03:20 PM »
Nice thing about early missions with a small crew is the very large cargo capacity. Extra life support supplies such as oxygen and water to replenish ECLSS can be carried. Spare parts too. Of course, that won't work with 100 people on board, but there will be many years to develop large capacity systems.

Offline sghill

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #4 on: 05/11/2017 03:24 PM »
Supporting 100 people for months in zero-g requires new systems and techniques.  100 bored passengers needing to eat, poop, and clean themselves are going to be a mess.

I don't think that this is a high priority item for SpaceX. Initially we will mostly see unmanned freighters and manned ships with a relatively small exploration crew (less than 20, I assume). That's based on Paul Woosters recent presentation were he said: "We have a lot of margin for early missions, which is quite helpful.". "a lot of margin" IMHO precludes 100 passengers.
Right - it's going to be a while yet before we see 100-person crews.  It is indeed going to be a massive pain supporting 100 people for 6-month-some voyagers...but developing an ECLSS precursor that can handle something in the 5-20 person range ought to be possible and also possible to incrementally refine.  It will likely take a combination of NASA input and SpaceX's 'aggressive persistence' to go from 5 to finally 100.

The initial crew size is a strawman argument. They've got to design the spacecraft now for maximum crew size.  ECLSS isn't something that is bolted on board and changes with crew sizes. Plumbing and storage tanks will be integral to the design from Day 1.

If it's easier on the systems with a smaller crew sobeit, but that doesn't change the immediacy of the design need.
« Last Edit: 05/11/2017 03:26 PM by sghill »
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Offline DanielW

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #5 on: 05/11/2017 03:41 PM »
If you make a per deck modular system, or two per deck, then the only thing that needs to be full scale on early flights is the Atmosphere handling system. Fans and Ducts to avoid dead spaces. Then you only need to outfit one deck with CO2 scrubbing, Oxygen generation, Lavatories etc for early missions. But yes space will need to be allocated to install systems on each deck.

Conversely there are probably economies of scale, with regards to mass, that dictate that you should build it all at once.

Offline JamesH65

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #6 on: 05/11/2017 03:46 PM »
Supporting 100 people for months in zero-g requires new systems and techniques.  100 bored passengers needing to eat, poop, and clean themselves are going to be a mess.

I don't think that this is a high priority item for SpaceX. Initially we will mostly see unmanned freighters and manned ships with a relatively small exploration crew (less than 20, I assume). That's based on Paul Woosters recent presentation were he said: "We have a lot of margin for early missions, which is quite helpful.". "a lot of margin" IMHO precludes 100 passengers.
Right - it's going to be a while yet before we see 100-person crews.  It is indeed going to be a massive pain supporting 100 people for 6-month-some voyagers...but developing an ECLSS precursor that can handle something in the 5-20 person range ought to be possible and also possible to incrementally refine.  It will likely take a combination of NASA input and SpaceX's 'aggressive persistence' to go from 5 to finally 100.

The initial crew size is a strawman argument. They've got to design the spacecraft now for maximum crew size.  ECLSS isn't something that is bolted on board and changes with crew sizes. Plumbing and storage tanks will be integral to the design from Day 1.

If it's easier on the systems with a smaller crew sobeit, but that doesn't change the immediacy of the design need.

I think I disagree. They could have some idea of the final volume required, but they don't need to fill it with the full version - that could be retrofitted later.

Offline RonM

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #7 on: 05/11/2017 03:46 PM »
Supporting 100 people for months in zero-g requires new systems and techniques.  100 bored passengers needing to eat, poop, and clean themselves are going to be a mess.

I don't think that this is a high priority item for SpaceX. Initially we will mostly see unmanned freighters and manned ships with a relatively small exploration crew (less than 20, I assume). That's based on Paul Woosters recent presentation were he said: "We have a lot of margin for early missions, which is quite helpful.". "a lot of margin" IMHO precludes 100 passengers.
Right - it's going to be a while yet before we see 100-person crews.  It is indeed going to be a massive pain supporting 100 people for 6-month-some voyagers...but developing an ECLSS precursor that can handle something in the 5-20 person range ought to be possible and also possible to incrementally refine.  It will likely take a combination of NASA input and SpaceX's 'aggressive persistence' to go from 5 to finally 100.

The initial crew size is a strawman argument. They've got to design the spacecraft now for maximum crew size.  ECLSS isn't something that is bolted on board and changes with crew sizes. Plumbing and storage tanks will be integral to the design from Day 1.

If it's easier on the systems with a smaller crew sobeit, but that doesn't change the immediacy of the design need.

It would be wise to plan ahead. However, the crew area is very large and can be significantly modified. SpaceX can move to more of an airplane model as far as crew interior design is concerned.

Offline Negan

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #8 on: 05/11/2017 03:50 PM »
Had the same questions too. Found this paper that spells out the fundamentals in detail. I agree with others that 100 is the goal, but won't be a gating item for the first missions.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100036823.pdf

Offline Norm38

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #9 on: 05/11/2017 03:53 PM »
Why would water vapor be dumped to atmosphere only to be scrubbed back out?  With a bunch of people breathing and sweating (exercise), bathing, I don't think low humidity will be a problem.

Offline Tomness

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #10 on: 05/11/2017 06:14 PM »
100 people won't be habitating in these things, they will be asleep

Offline docmordrid

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #11 on: 05/11/2017 07:33 PM »
100 people won't be habitating in these things, they will be asleep

ISTM that initially torpor won't yet be proven for months long voyages so do it in shifts, perhaps 2-3 weeks at a time, with medical staff also in rotation for addressing problems.
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Offline sghill

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #12 on: 05/11/2017 08:59 PM »
Supporting 100 people for months in zero-g requires new systems and techniques.  100 bored passengers needing to eat, poop, and clean themselves are going to be a mess.

I don't think that this is a high priority item for SpaceX. Initially we will mostly see unmanned freighters and manned ships with a relatively small exploration crew (less than 20, I assume). That's based on Paul Woosters recent presentation were he said: "We have a lot of margin for early missions, which is quite helpful.". "a lot of margin" IMHO precludes 100 passengers.
Right - it's going to be a while yet before we see 100-person crews.  It is indeed going to be a massive pain supporting 100 people for 6-month-some voyagers...but developing an ECLSS precursor that can handle something in the 5-20 person range ought to be possible and also possible to incrementally refine.  It will likely take a combination of NASA input and SpaceX's 'aggressive persistence' to go from 5 to finally 100.

The initial crew size is a strawman argument. They've got to design the spacecraft now for maximum crew size.  ECLSS isn't something that is bolted on board and changes with crew sizes. Plumbing and storage tanks will be integral to the design from Day 1.

If it's easier on the systems with a smaller crew sobeit, but that doesn't change the immediacy of the design need.

I think I disagree. They could have some idea of the final volume required, but they don't need to fill it with the full version - that could be retrofitted later.

That is impractical with a production run that can be counted on one hand. They're not building 737's (or even Falcon 9's) and then stretched versions after numerous unit sales. The initial version is the final version.

100 people won't be habitating in these things, they will be asleep

Source for that statement please. If we could do that now, we'd have tested it on ISS- or at least heard of it being done in the news.

It would be wise to plan ahead. However, the crew area is very large and can be significantly modified. SpaceX can move to more of an airplane model as far as crew interior design is concerned.

Take a look at a space shuttle schematic. The crew interior area is not dominated by plumbing and fixtures, it's dominated by storage lockers and open space. Everything else is behind the walls and in the floors and ceilings. That part has to be designed from the outset because it affects structure, COG, the design of the pressure wessel, and how the thing is constructed.

And if anything, Elon Musk has proven again and again across all of his companies that he builds the capability of future upgrades into his designs even if he doesn't have them on future versions. 

So, yes, the ECLSS system may be smaller on the first flight, but the time and the expense of this machine dictates it will move to 100 passengers as soon as habitat systems on Mars can support their arrival. 

Ergo, a scaled version of ECLSS is still a strawman argument that makes little business sense. Furthermore, because the ECLSS is a mission critical component, it's not something that's going to be retrofitted in after the first flight. Retrofitting, testing, and validation would require missing a launch window to make a modification that could have been baked in from the start.
This thread is intended to discuss the needs and systems that address those needs, and not how fast the needs are realized.
« Last Edit: 05/11/2017 09:17 PM by sghill »
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Offline Kaputnik

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #13 on: 05/11/2017 09:41 PM »
The ITS ship is capable of being built as a tanker, speculatively as an Earth-orbit sat launcher, as a Mars carg lander, as a combined cargo/crew lander, and as a pure crew lander. That is a lot of different configurations.

IMHO they could take the unmanned cargo lander design and bolt on the necessary ECLSS to support a minimal pioneer crew, without any detriment to the eventual 100-person design.
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Offline RonM

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #14 on: 05/11/2017 09:42 PM »
Something like the International Standard Payload Rack used on ISS would make it easy to reconfigure ITS spacecraft. Might be useful if the racks were a little bigger (whatever can fit through the larger hatch). Every detail of the ECLSS doesn't have to be decided from the start if there are equipment racks that can be swapped out.

Offline AncientU

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #15 on: 05/11/2017 11:41 PM »
Supporting 100 people for months in zero-g requires new systems and techniques.  100 bored passengers needing to eat, poop, and clean themselves are going to be a mess.

I don't think that this is a high priority item for SpaceX. Initially we will mostly see unmanned freighters and manned ships with a relatively small exploration crew (less than 20, I assume). That's based on Paul Woosters recent presentation were he said: "We have a lot of margin for early missions, which is quite helpful.". "a lot of margin" IMHO precludes 100 passengers.
Right - it's going to be a while yet before we see 100-person crews.  It is indeed going to be a massive pain supporting 100 people for 6-month-some voyagers...but developing an ECLSS precursor that can handle something in the 5-20 person range ought to be possible and also possible to incrementally refine.  It will likely take a combination of NASA input and SpaceX's 'aggressive persistence' to go from 5 to finally 100.

The initial crew size is a strawman argument. They've got to design the spacecraft now for maximum crew size.  ECLSS isn't something that is bolted on board and changes with crew sizes. Plumbing and storage tanks will be integral to the design from Day 1.

If it's easier on the systems with a smaller crew sobeit, but that doesn't change the immediacy of the design need.

I think I disagree. They could have some idea of the final volume required, but they don't need to fill it with the full version - that could be retrofitted later.

I know I don't agree.  Maybe you are picturing one of these classical waterfall design and build efforts that takes decades and armies... SpaceX is quite nimble and can easily evolve the balance between travelers supported and cargo carried.  The ECLSS, for instance could be modular, where one unit was capable of handling 10 travelers.  Build three units for redundancy, and use remaining mass/volume budget for surface cargo, supplies, whatever.  As the number on board increases, increase the ECLSS modules, always keeping sufficient spares for redundancy needs.

As a bonus, any modular systems can be left on Mars instead of being lugged back to Earth needlessly when they could have been used on Mars.
« Last Edit: 05/12/2017 06:30 PM by AncientU »
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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #16 on: 05/12/2017 12:24 AM »
100 people won't be habitating in these things, they will be asleep

ISTM that initially torpor won't yet be proven for months long voyages so do it in shifts, perhaps 2-3 weeks at a time, with medical staff also in rotation for addressing problems.
This is for the 500 passenger variant of ITS, not the 10-100 variant. :)
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Offline su27k

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #17 on: 05/12/2017 02:18 AM »
Supporting 100 people for months in zero-g requires new systems and techniques.  100 bored passengers needing to eat, poop, and clean themselves are going to be a mess.

I don't think that this is a high priority item for SpaceX. Initially we will mostly see unmanned freighters and manned ships with a relatively small exploration crew (less than 20, I assume). That's based on Paul Woosters recent presentation were he said: "We have a lot of margin for early missions, which is quite helpful.". "a lot of margin" IMHO precludes 100 passengers.
Right - it's going to be a while yet before we see 100-person crews.  It is indeed going to be a massive pain supporting 100 people for 6-month-some voyagers...but developing an ECLSS precursor that can handle something in the 5-20 person range ought to be possible and also possible to incrementally refine.  It will likely take a combination of NASA input and SpaceX's 'aggressive persistence' to go from 5 to finally 100.

The initial crew size is a strawman argument. They've got to design the spacecraft now for maximum crew size.  ECLSS isn't something that is bolted on board and changes with crew sizes. Plumbing and storage tanks will be integral to the design from Day 1.

If it's easier on the systems with a smaller crew sobeit, but that doesn't change the immediacy of the design need.

They can redesign it later. I mean how can anyone expect them to come up with the final design on first try, given how many iterations Falcon 9 (and to a less degree, Dragon) has gone though? The first ITS would be like the first Falcon 9/Dragon, which they later joked they didn't know what they were doing, the 100 people ITS would be like Block 5/Dragon 2.

Offline MP99

I still like the idea of an open loop system - use the carbohydrates in the food (reclaimed from CO2, water vapour, liquid and solid wastes) to create methalox which then gets dumped in the prop tanks.

The mass saved in prop at TMI could then be retasked to consumables.

Of course, this doesn't make for a simple system (no such thing exists when it comes to ECLSS) but it does reduce the level of recycling which is required to survive the flight.

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Offline IRobot

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #19 on: 05/12/2017 08:20 PM »
My guess is that the 100 passengers number is the same as the Airbus A-380 +800 passengers.
In reality, no company operates it at full capacity, usually they use less than 60%.

My guess is that passengers will mostly book premium passages, with more room, so less pressure on ECLSS.

My prediction for the initial crew is around 12. Several Mars mission proposals have stated that +6 would be ideal and I think SpaceX wants to put up a mission with more crew members than NASA could ever dream by 2030's. So 12.

Also if the initial mission is 100% privately funded (doubt that), it will have some sort of a reality show thing to it, so more characters, more interest it gathers.

Offline DanielW

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #20 on: 05/13/2017 05:32 AM »
I expect that early eclss will be a bit unwieldy and prone to needing repairs, but it will also probably be the area of spaceflight that sees the most rapid iteration and development. These systems will be going into everything from spacesuits to space ships with rovers and other equipment in-between.

Mars greatest IP export will probably be things we desperately need on earth. Better water purifiers, recycling, and manufacturing.

I suspect that many of the performance gains the ITS makes over the next few decades will come from mass savings in ECLSS.

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #21 on: 05/13/2017 06:58 PM »
The typical Mars trip is relatively short. Because of this, in some aspects, open loop systems are lighter and definitely less complex. I wouldn't rule them out.

OTOH the Mars surface systems have to operate indefinitely, but have an environment to interact with, (and are not zero g) so are not really related.

I won't be too surprised if they end up with simple chemical CO2 scrubbers - if nothing else then because of reliability.
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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #22 on: 05/16/2017 01:01 AM »
I would because chemical scrubbers get very heavy and simple regenerative (not closed loop) scrubbers are very lightweight.
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Offline RocketmanUS

Supporting 100 people for months in zero-g requires new systems and techniques.  100 bored passengers needing to eat, poop, and clean themselves are going to be a mess.

I don't think that this is a high priority item for SpaceX. Initially we will mostly see unmanned freighters and manned ships with a relatively small exploration crew (less than 20, I assume). That's based on Paul Woosters recent presentation were he said: "We have a lot of margin for early missions, which is quite helpful.". "a lot of margin" IMHO precludes 100 passengers.
Right - it's going to be a while yet before we see 100-person crews.  It is indeed going to be a massive pain supporting 100 people for 6-month-some voyagers...but developing an ECLSS precursor that can handle something in the 5-20 person range ought to be possible and also possible to incrementally refine.  It will likely take a combination of NASA input and SpaceX's 'aggressive persistence' to go from 5 to finally 100.

The initial crew size is a strawman argument. They've got to design the spacecraft now for maximum crew size.  ECLSS isn't something that is bolted on board and changes with crew sizes. Plumbing and storage tanks will be integral to the design from Day 1.

If it's easier on the systems with a smaller crew sobeit, but that doesn't change the immediacy of the design need.
Added cost to develop. they already know the first crews will be small exploration crews. As they build new BFS's in later years they would build them with the newer tech to handle greater crew size. They think they could carry as many as 200 crew, but that is a way off in the future.

I expect the first crew size to be 12 people. If on BFS has an issue crew could transfer to another BFS. So I expect the life support system to be able to handle 24 crew, This could keep the mass down so the craft could reach mars in less time.

The is the power issue and how much heat the BFS can radiate. More equipment and more crew would add more heat needed to reject. For the power the solar cell tech will need to evolve. More electrical power produced for a given mass and size.

So do to cost, time, and need of size of crew to start with i believe they will start with as much off the shelf tech as they can for a crew number of no more than 24. Later if there is a demand for crew sizes 100 or more then they or others would develop the next generation of life support systems needed for the BFS.

The BFS could carry two systems. One for micro gravity of space and the other for Mars gravity as needed.
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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #24 on: 05/16/2017 02:01 AM »
I'd bet money that SpaceX is not skimping on the sophistication of their ITS ECLSS. Any takers?
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Offline RocketmanUS

I'd bet money that SpaceX is not skimping on the sophistication of their ITS ECLSS. Any takers?
Over time sure. But not at the expense of getting to Mars sooner than someone else. Just how much will it cost for the first test flight? What does a replacement unit cost? So for a $10B budget is there room to gamble on ones dream to goto Mars?

So I believe they would put their investment in the flight hardware and then the life support system later. Cargo flights will be first anyway and the next window would not be for another 26 months/ That is added time to get a crew version ready ( Dragon cargo to Dragon 2 crew example ).
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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #26 on: 05/16/2017 02:35 AM »
I'd bet money that SpaceX is not skimping on the sophistication of their ITS ECLSS. Any takers?
Over time sure. But not at the expense of getting to Mars sooner than someone else. Just how much will it cost for the first test flight? What does a replacement unit cost? So for a $10B budget is there room to gamble on ones dream to goto Mars?

So I believe they would put their investment in the flight hardware and then the life support system later. Cargo flights will be first anyway and the next window would not be for another 26 months/ That is added time to get a crew version ready ( Dragon cargo to Dragon 2 crew example ).
I'm saying I think they're probably working on a (very good) ECLSS right now. Doesn't mean they won't have a backup. ISS carries oxygen candles just in case.
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Offline RocketmanUS

I'd bet money that SpaceX is not skimping on the sophistication of their ITS ECLSS. Any takers?
Over time sure. But not at the expense of getting to Mars sooner than someone else. Just how much will it cost for the first test flight? What does a replacement unit cost? So for a $10B budget is there room to gamble on ones dream to goto Mars?

So I believe they would put their investment in the flight hardware and then the life support system later. Cargo flights will be first anyway and the next window would not be for another 26 months/ That is added time to get a crew version ready ( Dragon cargo to Dragon 2 crew example ).
I'm saying I think they're probably working on a (very good) ECLSS right now. Doesn't mean they won't have a backup. ISS carries oxygen candles just in case.
As for backup system I was thinking just a second set. However a different design would be better ( from a proven system ).

So do you think they will evolve their ECLSS over time to grow for greater crew numbers like 100?
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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #28 on: 05/16/2017 09:40 AM »
Regarding crew sizes, some systems are going to be able to scale while others may not.

The pressurised volume is going to be fixed early in the design and will be for 100 people. Therefore the air volume is going to be pretty close to that. If you cram the space with cargo won't that just become a bacteria/fungus trap?

Water storage has long been mentioned as being needed for solar storm protection. If a crew of 10 brings only its share of water they only get one tenth the protection?

The only thing my naive brain did think could be shrunk was the laundry. No point bringing equipment to clean 100 shirts a week if you only use 10. Also toilets and showers...

Offline IRobot

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #29 on: 05/16/2017 09:58 AM »
The pressurised volume is going to be fixed early in the design and will be for 100 people.
If I could bet somewhere, I would bet that they will never carry 100 people on ITS. It is capability advertisement, like the A380 stating it can take +800 people, when in reality it takes less than 60% of that value.
Maybe we should stick the discussion with smaller crew sizes.

Offline john smith 19

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #30 on: 05/16/2017 11:55 AM »
The typical Mars trip is relatively short. Because of this, in some aspects, open loop systems are lighter and definitely less complex. I wouldn't rule them out.

OTOH the Mars surface systems have to operate indefinitely, but have an environment to interact with, (and are not zero g) so are not really related.

I won't be too surprised if they end up with simple chemical CO2 scrubbers - if nothing else then because of reliability.
Standard NASA allowance for air/water/food is 5Kg/person/day. Open loop for a 10 person crew on a 50 day (v.fast) trip that's 2.5 tonnes. Double that for a 100 day trip (both one way).

But at 100 people you're at 25 tonnes for a 50 day voyage, 50 tonnes for a 100. Something like 75% of that mass is water, whose recovery is well understood.

People forget there are multiple ISS systems doing water, urine and air recycling. {EDIT to be clear I believe there are a couple of versions of each system IE NASA, ESA and Russia in some cases. All are a bit different and all have different strengths and weaknesses. I believe there is enough track record between them to design and build quite an effective ECLSS right now] They're all very much pilot systems but could probably all serve as the model for a working system on ITS.
[EDIT If we are serious about exploring the Solar System we cannot go on doing it by leaving a trail of urine dumps and food packaging in our wake across the system.   :( ]
« Last Edit: 05/17/2017 01:24 PM by john smith 19 »
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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #31 on: 05/17/2017 02:25 AM »
The pressurised volume is going to be fixed early in the design and will be for 100 people.
If I could bet somewhere, I would bet that they will never carry 100 people on ITS. It is capability advertisement, like the A380 stating it can take +800 people, when in reality it takes less than 60% of that value.
Maybe we should stick the discussion with smaller crew sizes.
Musk proposed even more passengers for a follow-on, like 200+.

I don't see why your unfounded opinion that SpaceX isn't serious about large numbers of passengers should dictate the course of the discussion.
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Offline sghill

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #32 on: 05/18/2017 03:02 PM »
I don't see open loop systems having as much value as closed loop systems.

Anything organic will have incredible value on Mars- even human wastes. They may not want to use it immediately, but compost delivered to Mars would be mind-boggling expensive for what it is, so it won't go to waste, IMHO.
« Last Edit: 05/18/2017 03:03 PM by sghill »
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Offline MP99



The BFS could carry two systems. One for micro gravity of space and the other for Mars gravity as needed.

ISTM optimising an ECLSS system to work in both environments would add a lot of complexity.

I could certainly see how there would be good reason to have two separate systems.

Cheers, Martin

Offline jpo234

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #34 on: 05/18/2017 03:59 PM »
Musk proposed even more passengers for a follow-on, like 200+.

I don't see why your unfounded opinion that SpaceX isn't serious about large numbers of passengers should dictate the course of the discussion.

I don't think anybody doubts that SpaceX eventually want's these numbers of passengers. What is debatable however, is the premise of the original post, that the full scale ECLSS will be an integral part of the BFS and those has to be ready for the first manned flight.

I think, that this is not an immediate challenge. Initial missions will be exploratory with relatively small crews. These exploratory flights can use a conventional ECLSS. The full scale system is further into the future, maybe 20 years after the first manned mission or 25 to 30 years from now.

Offline Negan

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #35 on: 05/18/2017 04:12 PM »


The BFS could carry two systems. One for micro gravity of space and the other for Mars gravity as needed.

ISTM optimising an ECLSS system to work in both environments would add a lot of complexity.

I could certainly see how there would be good reason to have two separate systems.

Cheers, Martin

What systems wouldn't work in both?

Offline Kaputnik

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #36 on: 05/18/2017 04:15 PM »


The BFS could carry two systems. One for micro gravity of space and the other for Mars gravity as needed.

ISTM optimising an ECLSS system to work in both environments would add a lot of complexity.

I could certainly see how there would be good reason to have two separate systems.

Cheers, Martin

Absolutely. There are so many differences.
An in-space ECLSS has to work without any external inputs except solar power, has to work in microgravity, and has to be optimised for low mass and reliability over the period of time for the Mars transfer flight.
A Mars surface ECLSS has to work in 0.38g, is less mass sensitive, has access to abundant external CO2 and perhaps also H2O, and will, crucially, have to synergise with other systems including propellant production and power production. Parts of the process may act as heatsinks for nuclear power sources, or as dump loads for solar. Oxygen may be produced as a byproduct of propellant manufacture (Tom Mueller said as much in the recent interview).
There is also much more scope, on the ground, for biological systems- e.g. greenhouses producing food and oxygen. The timescale, mass, and space required for these systems make sense on the ground, but not on the ITS.
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Offline john smith 19

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #37 on: 05/18/2017 06:52 PM »


The BFS could carry two systems. One for micro gravity of space and the other for Mars gravity as needed.

ISTM optimising an ECLSS system to work in both environments would add a lot of complexity.

I could certainly see how there would be good reason to have two separate systems.

Cheers, Martin
If there's one thing I think SX have shown it's that they are very wary of "optimization." Good enough to get the job done seems to be more their style, preferably with enough growth designed in to allow the system to stretch.

On that basis the first version of ITS will fly with a V1.0 ECLSS. My guess is it will be quite conservative for the initial size of crew ITS will carry (lots of empty slots in the appropriate racks) but SX gain experience and send more people the racks will fill up and they will feel OK with reducing the necessary margins.

I'm thinking of way the Merlin engine has evolved from the initially ablative cooled version to the one we know today.
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Offline RocketmanUS

I don't see open loop systems having as much value as closed loop systems.

Anything organic will have incredible value on Mars- even human wastes. They may not want to use it immediately, but compost delivered to Mars would be mind-boggling expensive for what it is, so it won't go to waste, IMHO.
Cost?
Reliability?
Size?
Power required?
Added heat generated needing to be expelled?
Time to develop before first crew mission?

These are some of the things that need to be looked at in order to see what system would be better for the first generation ECLSS for the BFS.
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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #39 on: 05/19/2017 01:32 AM »


The BFS could carry two systems. One for micro gravity of space and the other for Mars gravity as needed.

ISTM optimising an ECLSS system to work in both environments would add a lot of complexity.

I could certainly see how there would be good reason to have two separate systems.

Cheers, Martin
If there's one thing I think SX have shown it's that they are very wary of "optimization." Good enough to get the job done seems to be more their style, preferably with enough growth designed in to allow the system to stretch.
A reasonable perspective through the first 5 Falcon 9 flights.

Increasingly not so afterwards. Merlin 1D is thrust-to-weight ratio optimized to all heck (smashing previous records for any liquid engine). Mass fraction is increasingly good. I mean, they're the first group to deeply subcool rocket propellants (some Russian engines use somewhat subcooled LOx, but not nearly as deeply subcooled) for operational rockets. They stuck their COPVs in the subcooled LOx tank (which is basically the complete opposite of being wary of optimization). They don't gently land F9 like New Shepard but instead hoverslam it. ITS takes this to a whole new level (Raptor, the most insane rocket engine ever, and landing a ridiculously over powered rocket on just a launch cradle?? Are they insane??), and I'm certain the ITS ECLSS they're working on will be no different.

Quote
On that basis the first version of ITS will fly with a V1.0 ECLSS. My guess is it will be quite conservative for the initial size of crew ITS will carry (lots of empty slots in the appropriate racks) but SX gain experience and send more people the racks will fill up and they will feel OK with reducing the necessary margins.

I'm thinking of way the Merlin engine has evolved from the initially ablative cooled version to the one we know today.
Dragon will fly with life support. That's your ECLSS v1.0. No one ever suggested the ITS ECLSS wouldn't have margins (so I'm not sure where that comment is aimed at) since it's going to have a smaller crew to start out with, but I sincerely doubt it's anything other than an attempt at a significant improvement over the State of the Art.
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Offline john smith 19

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #40 on: 05/19/2017 10:20 AM »
A reasonable perspective through the first 5 Falcon 9 flights.

Increasingly not so afterwards. Merlin 1D is thrust-to-weight ratio optimized to all heck (smashing previous records for any liquid engine). Mass fraction is increasingly good. I mean, they're the first group to deeply subcool rocket propellants (some Russian engines use somewhat subcooled LOx, but not nearly as deeply subcooled) for operational rockets. They stuck their COPVs in the subcooled LOx tank (which is basically the complete opposite of being wary of optimization). They don't gently land F9 like New Shepard but instead hoverslam it. ITS takes this to a whole new level (Raptor, the most insane rocket engine ever, and landing a ridiculously over powered rocket on just a launch cradle?? Are they insane??), and I'm certain the ITS ECLSS they're working on will be no different.
All of which they could do with confidence based on their experience of those first 5 flights.
Quote from: Robotbeat
Dragon will fly with life support. That's your ECLSS v1.0. No one ever suggested the ITS ECLSS wouldn't have margins (so I'm not sure where that comment is aimed at) since it's going to have a smaller crew to start out with, but I sincerely doubt it's anything other than an attempt at a significant improvement over the State of the Art.
ITS will be a step change over Dragon in terms of active (not stand by) life time and size. I expect the ITS ECLSS to have very wide margins on first flight a)Because to support a full load of 100 passengers and b) Because it will not have a full 100 passengers to begin with.
What I meant by margin is that as they gain operating experience SX will relax just how high a margin they keep to support the full 100 passengers, not just the margin due to the early crews being much smaller than full capacity.

AFAIK this process, relaxing the operating margin, has been a key part of how Merlin was designed. In principle a large part of Merlins upgrade could just have been down to larger diameter pipes feeding the GG, the CC and the turbo pumps, once all the data collected from previous flights showed they were safe to do so. No radical redesign needed (although I believe mfg methods for large parts of Merlin have changed quite a bit).
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Offline Kaputnik

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #41 on: 05/19/2017 11:20 AM »
Some of these posts seems to suggest that the first few ITS flights would have a dozen people rattling about in an almost empty cabin built for 100.
That seems highly unlikely. IMHO the first crewed flights will be hybrid crew+cargo vehicles. Probably much more utilitarian than the eventual passenger vehicle. They won't want to waste a single litre of space, nor a single kg of mass. Hence the ECLSS may be quite different, at least in scale.
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Offline guckyfan

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #42 on: 05/19/2017 12:57 PM »
Some of these posts seems to suggest that the first few ITS flights would have a dozen people rattling about in an almost empty cabin built for 100.
That seems highly unlikely. IMHO the first crewed flights will be hybrid crew+cargo vehicles. Probably much more utilitarian than the eventual passenger vehicle. They won't want to waste a single litre of space, nor a single kg of mass. Hence the ECLSS may be quite different, at least in scale.

What kind of flight trajectory do you expect? If they fly slow they could take a large amount of payload. But I think they will stick to a fast transfer for crew. They will fly most of the cargo on one or two separate cargo flights. So no more than 200t of cargo and it would be empty. Even if they take more I don't think they will approach the max. 450t but rather the 300t ITS can lift to LEO without adding cargo in orbit.

Offline AncientU

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #43 on: 05/19/2017 01:02 PM »
Some of these posts seems to suggest that the first few ITS flights would have a dozen people rattling about in an almost empty cabin built for 100.
That seems highly unlikely. IMHO the first crewed flights will be hybrid crew+cargo vehicles. Probably much more utilitarian than the eventual passenger vehicle. They won't want to waste a single litre of space, nor a single kg of mass. Hence the ECLSS may be quite different, at least in scale.

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Offline DOCinCT

Some of these posts seems to suggest that the first few ITS flights would have a dozen people rattling about in an almost empty cabin built for 100.
That seems highly unlikely. IMHO the first crewed flights will be hybrid crew+cargo vehicles. Probably much more utilitarian than the eventual passenger vehicle. They won't want to waste a single litre of space, nor a single kg of mass. Hence the ECLSS may be quite different, at least in scale.
If you think USN Virginia Class submarine aesthetics with about 32 crew on a 6 month voyage and 18 months on the surface you get something like this for the non-flight crew decks and commissary/recreation deck.

Offline john smith 19

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #45 on: 05/21/2017 03:04 PM »
Some of these posts seems to suggest that the first few ITS flights would have a dozen people rattling about in an almost empty cabin built for 100.
That seems highly unlikely. IMHO the first crewed flights will be hybrid crew+cargo vehicles. Probably much more utilitarian than the eventual passenger vehicle. They won't want to waste a single litre of space, nor a single kg of mass. Hence the ECLSS may be quite different, at least in scale.
If you think USN Virginia Class submarine aesthetics with about 32 crew on a 6 month voyage and 18 months on the surface you get something like this for the non-flight crew decks and commissary/recreation deck.
Are you assuming some kind of artificial gravity? Yes it will have to land on Mars but during it's voyage accessing the ceiling will be much easier.

Given SX's fondness for building a core vehicle and then stretching it to give new capabilities you might like to consider a core vehicle with fixed bridge and (small) crew area with the rest being uncommitted storage or "hold".   :)
The hold area can then be configured depending on a mix of human or cargo levels and can accommodate some very large single structures (provided they can be assembled within the hold and be operated there after landing).

On Earth this has been done by cargo airlines branching out into budget tour operators by installing palletised seating, galley and toilet facilities in their freighter deck, as well as a Scandinavian multi purpose military vessel design with a large open deck (IE an open plan area, not a top deck with new fittings on it) that can accommodate various mission modules.
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Offline docmordrid

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #46 on: 05/21/2017 05:02 PM »
It seems Honeywell and Paragon SDC have partnered for  creating a deep space ECLSS

https://www.honeywell.com/newsroom/pressreleases/2017/05/honeywell-and-paragon-to-create-life-support-technology-for-future-nasa-space-missions

Quote
PHOENIX, May 1, 2017 /PRNewswire/ -- Honeywell (NYSE: HON) and Paragon Space Development Corporation have announced a teaming agreement that will change the way astronauts experience life in space. The two companies will design, build, test and apply environmental control and life support systems for future human NASA and commercial programs.

Longer duration, human-exploration missions are planned for the future, but there is no easy way to replenish resources such as oxygen and water in space. NASA's future human-exploration missions will require an integrated and highly efficient system for life support and thermal control. Paragon's focus on evolving water and thermal technologies complements Honeywell's new developments in air revitalization technologies, both of which are essential parts of the spacecraft needed for NASA's deep space goals.

"A renewed interest in developing a Deep Space Habitat needed for reaching the Moon and Mars, continued experimentation aboard the International Space Station, and a desire to push the limits of unmanned flights make this a remarkable time in space exploration. Unmanned achievements are now giving way to long-distance and long-duration human missions. The technology developed by Honeywell and Paragon will give humans the opportunity to explore space for longer periods than before," said Marty Sheber, vice president, Space, Honeywell Aerospace. "Honeywell has a long legacy of providing mission-critical environmental control and life support systems (ECLSS), including being the provider of critical parts of the system currently used on the International Space Station. That heritage, coupled with Paragon's focus on innovative and emerging ECLSS technologies, provides a complementary team to develop technology capable of supporting humans on their longer explorations into space."
>

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Online Jcc

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #47 on: 06/19/2017 11:35 PM »
I think a number of smaller, identical ECLSS systems is better than one big one, just like the many Raptor engines to provide fail safe thrust. There is something to say for having an equal number of dissimilar systems, but there is trade-off in terms of development cost, training to maintain multiple systems, keeping spare parts, etc.

Offline tdperk

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #48 on: 08/06/2017 05:51 PM »
Is there a thread documentating the current state of the art in ECLSS hardware and concepts?

Offline Jim

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #49 on: 08/06/2017 07:31 PM »
I think a number of smaller, identical ECLSS systems is better than one big one, just like the many Raptor engines to provide fail safe thrust. There is something to say for having an equal number of dissimilar systems, but there is trade-off in terms of development cost, training to maintain multiple systems, keeping spare parts, etc.

Not really, it doesn't work for HVAC systems.  One big system with many smaller parts

Offline tdperk

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #50 on: 08/06/2017 11:14 PM »
I think a number of smaller, identical ECLSS systems is better than one big one, just like the many Raptor engines to provide fail safe thrust. There is something to say for having an equal number of dissimilar systems, but there is trade-off in terms of development cost, training to maintain multiple systems, keeping spare parts, etc.

Not really, it doesn't work for HVAC systems.  One big system with many smaller parts

You comment in no way resembles a reply to what Jcc wrote.  Multiple independent parallel systems do provide redundancy less expensively than multiple system which in no way resemble each other.  That becomes a big system with big capabilities, which has smaller parts.

Offline Jim

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #51 on: 08/06/2017 11:20 PM »
Multiple independent is not the way to go.  That is where interactions have problems and the multiple systems fight each other. 

Offline tdperk

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #52 on: 08/07/2017 06:51 PM »
Multiple independent is not the way to go.  That is where interactions have problems and the multiple systems fight each other.

No, that's not necessarily what happens.  I do that quite commonly with multiple parallel identical systems drawing from and discharging to both the same vessel and in flow through processes.

Managing series and parallel flow processes with PID, both with multiple interacting integral values for differing portions of the process and single & multiple inputs, cascaded and not--I do that.  Not that I get  a chance every week, but I have the T-Shirt.

It's not hard to keep one loop from haring off the map, or to make the map adaptive to over-riding process requirements.

Offline lamontagne

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #53 on: 08/17/2017 01:17 AM »
I did these a while ago when the ITS was still the BFS.  The masses are not that great for 100 people, if we multiply the systems from the ISS.
I wonder if the numbers are valid or if there are scaling problems?
As far as open system vs closed ones, open for food and closed for the rest is the way to go, I think.

What might be the leak and loss rates for something like the ITS Spaceship?
The spreadsheet is attached as well.


« Last Edit: 08/17/2017 01:17 AM by lamontagne »

Offline lamontagne

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #54 on: 08/17/2017 01:23 AM »
One of the typical way we design ventilation systems these days is central cooling and heating, distributed using water pipes, and local ventilation units with coils, with only the fresh air being distributed over the building.  Makes for much smaller ductwork.
Each central system is redundant, while the local individual systems are not, since their failure doesn't affect the overall system.
We tend to have one ventilation system per type of usage.  This might be overkill for just 100 people.  As far as building go, this is a really small application.

Offline DAZ

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #55 on: 08/17/2017 03:07 AM »
I think a number of smaller, identical ECLSS systems is better than one big one, just like the many Raptor engines to provide fail safe thrust. There is something to say for having an equal number of dissimilar systems, but there is trade-off in terms of development cost, training to maintain multiple systems, keeping spare parts, etc.

Not really, it doesn't work for HVAC systems.  One big system with many smaller parts

Iím afraid Iím going to have to call you on this one and disagree.  I have been working with fielded mobile ECU systems for over 35 years.  35 years ago what you said was the prevailing engineering solution.  The thought was fewer parts, means fewer parts to fail and better system efficiency requiring less power.  All of this ends up to be totally wrong.

One big ECU system means one very big power surge whenever the system goes from idle to start.  So every time your compressors startup or your heater startup you are immediately at max load.  This means that your power source must be sized for this max surge load.  This means your power source has to be way over sized for your average load.  In addition, maximum efficiency is only obtained if you have to dissipate your maximum heat load or conversely need to generate your maximum heat.  In the real world, these systems have to operate usually vary from 30% to 100% of their max loads.  This means the system is rarely ever running at its maximum efficiency nor are your power sources operating at their maximum efficiencies.

With just one system you had a single point of failure.  As these systems are critical, this means that the whole system fails if they fail.  So the next prevailing engineering solution was to produce a 100% redundant system.  When one system failed you moved over to your backup.  This also followed with your power generation system.  All of this greatly increased the cost and physical size of the systems.

The most recent engineering solution is for multiple smaller systems.  These systems are not even necessarily sized identically.  These multiple systems are turned on and off as needed but never simultaneously.  This reduces the surge loads by an incredible amount.  Quite often you can reduce the peak power loads easily by over 50%.  The system may decide that it is running at 20% of load and start the system designed to handle 20% load at max efficiency.  If the load increases to 30% it then shuts down the 20% load system and starts a load system optimized for 30%.  If the load increases to 40% it would then start an additional system designed for 10% load with a total now being 40%.  When the load hits 50% the 10% load is shut down in the 20% load comes up.  At 60% the 20% load is turned back on.  This type of game continues all the way up to 100% load.  Not only does this provide for much greater efficiencies but also produces a system much more reliable through graceful redundancy if one of the systems does fail.  To provide redundancy at 100% you just need to provide one additional system at your largest sub system load.  And that would only be necessary if you knew your system was going to be running at 100%.  For example, if you knew your system needed to be designed for 100 bodies but at 1st was only going be running for 10 to 20 initially you could build a smaller system knowing that you would eventually build up to the larger system later.

This type of system is optimized for near maximum efficiencies and maximum redundancy but not for the minimum part count for spare parts.  If this is the more important option than the systems usually would be identical each one at letís say 20% of max load.  This would allow you to have a minimum number of spare parts and if necessary could cannibalize from one system to the other.

Not only are systems like this much more common in mobile systems but Iím seeing similar type systems being installed in buildings.  Even on systems that are going to run at near max load all the time i.e. server farms they are still going with multiple redundant systems.  This is still the more reliable efficient system.

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