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.
Quote from: sghill on 05/11/2017 01:41 pmSupporting 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.
Quote from: jpo234 on 05/11/2017 02:37 pmQuote from: sghill on 05/11/2017 01:41 pmSupporting 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.
Quote from: redliox on 05/11/2017 03:10 pmQuote from: jpo234 on 05/11/2017 02:37 pmQuote from: sghill on 05/11/2017 01:41 pmSupporting 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.
100 people won't be habitating in these things, they will be asleep
Quote from: sghill on 05/11/2017 03:24 pmQuote from: redliox on 05/11/2017 03:10 pmQuote from: jpo234 on 05/11/2017 02:37 pmQuote from: sghill on 05/11/2017 01:41 pmSupporting 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.
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.
Quote from: Tomness on 05/11/2017 06:14 pm100 people won't be habitating in these things, they will be asleepISTM 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.
I'd bet money that SpaceX is not skimping on the sophistication of their ITS ECLSS. Any takers?
Quote from: Robotbeat on 05/16/2017 02:01 amI'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 ).
Quote from: RocketmanUS on 05/16/2017 02:26 amQuote from: Robotbeat on 05/16/2017 02:01 amI'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.
The pressurised volume is going to be fixed early in the design and will be for 100 people.
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.
Quote from: chalz on 05/16/2017 09:40 amThe 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.
The BFS could carry two systems. One for micro gravity of space and the other for Mars gravity as needed.
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.
Quote from: RocketmanUS on 05/16/2017 01:55 amThe 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
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.
Quote from: MP99 on 05/18/2017 03:47 pmQuote from: RocketmanUS on 05/16/2017 01:55 amThe 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, MartinIf 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.
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.
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.
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.
Quote from: Kaputnik on 05/19/2017 11:20 amSome 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.
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.">
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.
Quote from: Jcc on 06/19/2017 11:35 pmI 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
Multiple independent is not the way to go. That is where interactions have problems and the multiple systems fight each other.
You can view the thesis here
Quote from: Jim on 08/06/2017 07:31 pmQuote from: Jcc on 06/19/2017 11:35 pmI 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 partsI’m afraid I’m going to have to call you on this one ... is still the more reliable efficient system.
Quote from: Maschbauer on 11/15/2017 08:21 amYou can view the thesis hereI 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!
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?