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