Author Topic: ITS Environmental Control and Life Support System (ECLSS)  (Read 10635 times)

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).
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

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.
Waiting for joy and raptor

Online 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.

Online 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.
"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Online 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."
>

DM

Offline 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.

Online 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 »

Online 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

I知 afraid I知 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 let痴 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 I知 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.

I bet SpaceX is not developing the ECLSS and instead use the know-how others have (Paragon  ;))

I recently wrote my Master-Thesis about this topic. The conclusion is, that an open-loop system is comparable in mass and volume to a partial-closed system when assuming current technology. The big advantage of an open-loop system is the much lower power and thermal requirements.
You can view the thesis here

Online speedevil

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #57 on: 11/15/2017 01:09 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!

Offline tdperk

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Re: ITS Environmental Control and Life Support System (ECLSS)
« Reply #58 on: 11/15/2017 02:17 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

I知 afraid I知 going to have to call you on this one ... is still the more reliable efficient system.

And how. :D

Tags: ITS ECLSS