Bigger modules, fewer launches, less time and risk on on-orbit assembly. Smaller modules, more launches, more risk.Remember that Americaspace article where the gentlemen from the SLS program said their thinking is "Keep it Simple, Stupid"? More launches, less simple.
Many NASA studies would disagree, and there was an MIT study that just came out this week that showed how fuel depots could greatly enhance our ability to go places in space (local space for sure).
Bigger modules, fewer launches, less time and risk on on-orbit assembly. Smaller modules, more launches, more risk.
Quote from: CNYMike on 03/10/2014 05:16 amBigger modules, fewer launches, less time and risk on on-orbit assembly. Smaller modules, more launches, more risk.We don't have the terrestrial capability to handle payloads larger than 5 meters and 20 tonnes. The industrial infrastructure doesn't support larger payloads. Not at Denver, Dulles, Sunnyvale, El Segundo, Redondo Beach, Palo Alto, Pasadena, Greensbelt, Gilbert, Boulder, etc where all spacecraft manufacturers are located.
* This study does not support the perception that depots add an unacceptable level of risk and should not be considered due to the increased number of launches, AR&Ds, and transfers.* Reduces risk of LOM by decoupling propellant delivery flights from delivery of mission elements (i.e., elements stay on the ground until needed for mission)
Quote from: Coastal Ron on 03/09/2014 09:04 pmQuote from: CNYMike on 03/09/2014 06:32 pmSo depots do not change when a mission to a given destination has to get under way. And that is determined by where the mission is going. Some things have to be determined; you can not just go "wherever whenever." How often you can go to a given destination is determined by celestial mechanics, not whether there's a fuel depot sitting somewhere.Maybe they don't change how often you can leave for destinations far away, but depots are part of the architecture that ensures that you can make your celestially-driven departure dates.NASA has met "celestial driven departure dates" for decades without magic depots.
Quote from: CNYMike on 03/09/2014 06:32 pmSo depots do not change when a mission to a given destination has to get under way. And that is determined by where the mission is going. Some things have to be determined; you can not just go "wherever whenever." How often you can go to a given destination is determined by celestial mechanics, not whether there's a fuel depot sitting somewhere.Maybe they don't change how often you can leave for destinations far away, but depots are part of the architecture that ensures that you can make your celestially-driven departure dates.
So depots do not change when a mission to a given destination has to get under way. And that is determined by where the mission is going. Some things have to be determined; you can not just go "wherever whenever." How often you can go to a given destination is determined by celestial mechanics, not whether there's a fuel depot sitting somewhere.
Quote from: Coastal Ron on 03/08/2014 08:21 pmMany NASA studies would disagree, and there was an MIT study that just came out this week that showed how fuel depots could greatly enhance our ability to go places in space (local space for sure).Would you have a link or hint as to where to find it?
Quote from: CNYMike on 03/10/2014 05:16 amQuote from: Coastal Ron on 03/09/2014 09:04 pmMaybe they don't change how often you can leave for destinations far away, but depots are part of the architecture that ensures that you can make your celestially-driven departure dates.NASA has met "celestial driven departure dates" for decades without magic depots. Just look at any spacecraft on or orbiting Mars. Curiosity had a very specific departure time not just to reach Mars but land at a specific spot. Made it. No depot. Whatever their advantages, that's one of them.Uh, those were all missions where everything that was needed for the mission flew on one launch (and pretty small hardware too). Are you saying that the roadmap for exploration that NASA is working on will never rely on more hardware than what can fit on one rocket?
Quote from: Coastal Ron on 03/09/2014 09:04 pmMaybe they don't change how often you can leave for destinations far away, but depots are part of the architecture that ensures that you can make your celestially-driven departure dates.NASA has met "celestial driven departure dates" for decades without magic depots. Just look at any spacecraft on or orbiting Mars. Curiosity had a very specific departure time not just to reach Mars but land at a specific spot. Made it. No depot. Whatever their advantages, that's one of them.
Maybe they don't change how often you can leave for destinations far away, but depots are part of the architecture that ensures that you can make your celestially-driven departure dates.
.... You are aware that NASA plans on using modular construction and in-space refueling with the SLS in order to go to Mars, right? It's not a nice to have, it's mandatory if we're going to go to Mars in any meaningful way.
Quote from: CNYMike on 03/10/2014 05:16 am"Assembly" does not equal "depot." Nor does in orbit fueling up require it. We have over 13 years of doing both with the ISS, and it makes no sense to do one but not the other.
"Assembly" does not equal "depot." Nor does in orbit fueling up require it.
Quote from: CNYMike on 03/10/2014 05:16 amBigger modules, fewer launches, less time and risk on on-orbit assembly. Smaller modules, more launches, more risk.Bigger is not always a magic solution, especially when you have to give up flexibility to get it. What's important is to pick the size that the entire "ecosystem" can support. As of today that is the 5m diameter family of payloads that are less than 20mt in mass. We have real data on how this architecture works, and ZERO on SLS-sized ones.
Quote from: CNYMike on 03/10/2014 05:16 amRemember that Americaspace article where the gentlemen from the SLS program said their thinking is "Keep it Simple, Stupid"? More launches, less simple.......As to KISS, that would be what we have today, not mythical architectures that have unproven value or need.
Remember that Americaspace article where the gentlemen from the SLS program said their thinking is "Keep it Simple, Stupid"? More launches, less simple.
Quote from: Jim on 03/10/2014 10:26 amQuote from: CNYMike on 03/10/2014 05:16 amBigger modules, fewer launches, less time and risk on on-orbit assembly. Smaller modules, more launches, more risk.We don't have the terrestrial capability to handle payloads larger than 5 meters and 20 tonnes. The industrial infrastructure doesn't support larger payloads. Not at Denver, Dulles, Sunnyvale, El Segundo, Redondo Beach, Palo Alto, Pasadena, Greensbelt, Gilbert, Boulder, etc where all spacecraft manufacturers are located.Tell the guys who did Skylab II.
Quote from: Coastal Ron on 03/10/2014 06:00 amQuote from: CNYMike on 03/10/2014 05:16 amQuote from: Coastal Ron on 03/09/2014 09:04 pmMaybe they don't change how often you can leave for destinations far away, but depots are part of the architecture that ensures that you can make your celestially-driven departure dates.NASA has met "celestial driven departure dates" for decades without magic depots. Just look at any spacecraft on or orbiting Mars. Curiosity had a very specific departure time not just to reach Mars but land at a specific spot. Made it. No depot. Whatever their advantages, that's one of them.Uh, those were all missions where everything that was needed for the mission flew on one launch (and pretty small hardware too). Are you saying that the roadmap for exploration that NASA is working on will never rely on more hardware than what can fit on one rocket?No, I am saying those mission did not need a depot to "ensure" they made "celestial driven departure dates."Quote.... You are aware that NASA plans on using modular construction and in-space refueling with the SLS in order to go to Mars, right? It's not a nice to have, it's mandatory if we're going to go to Mars in any meaningful way.Which means refueling, assembly, and the SLS are not mutually exclusive, even though SLS opponents act like they are.QuoteQuote from: CNYMike on 03/10/2014 05:16 am"Assembly" does not equal "depot." Nor does in orbit fueling up require it. We have over 13 years of doing both with the ISS, and it makes no sense to do one but not the other.And still no depot involved. I am responding to the notion that depots are the be-all-and-end-all, necessary to architectures. You keep pointing to examples where they are not used. QuoteQuote from: CNYMike on 03/10/2014 05:16 amBigger modules, fewer launches, less time and risk on on-orbit assembly. Smaller modules, more launches, more risk.Bigger is not always a magic solution, especially when you have to give up flexibility to get it. What's important is to pick the size that the entire "ecosystem" can support. As of today that is the 5m diameter family of payloads that are less than 20mt in mass. We have real data on how this architecture works, and ZERO on SLS-sized ones.You forgot about Skylab. I have a hunch it was bigger than those parameters, and probably what the guys behind the Skylab II study have in mind.QuoteQuote from: CNYMike on 03/10/2014 05:16 amRemember that Americaspace article where the gentlemen from the SLS program said their thinking is "Keep it Simple, Stupid"? More launches, less simple.......As to KISS, that would be what we have today, not mythical architectures that have unproven value or need.Your existing-rockets-and-depots architectures are just as mythical at this point.
Tell the guys who did Skylab II.
Quote from: Coastal Ron on 03/10/2014 06:00 amQuote from: CNYMike on 03/10/2014 05:16 amBigger modules, fewer launches, less time and risk on on-orbit assembly. Smaller modules, more launches, more risk.Bigger is not always a magic solution, especially when you have to give up flexibility to get it. What's important is to pick the size that the entire "ecosystem" can support. As of today that is the 5m diameter family of payloads that are less than 20mt in mass. We have real data on how this architecture works, and ZERO on SLS-sized ones.You forgot about Skylab. I have a hunch it was bigger than those parameters, and probably what the guys behind the Skylab II study have in mind.Quote from: Coastal Ron on 03/09/2014 09:04 pmQuote from: CNYMike on 03/10/2014 05:16 amRemember that Americaspace article where the gentlemen from the SLS program said their thinking is "Keep it Simple, Stupid"? More launches, less simple.......As to KISS, that would be what we have today, not mythical architectures that have unproven value or need.Your existing-rockets-and-depots architectures are just as mythical at this point.
Quote from: CNYMike on 03/10/2014 04:51 pmTell the guys who did Skylab II.They did nothing but pretty drawings
Mythbuster Checklist:
Of course, i hear that Spacex is building a one shot Mars rocket that should be able to send crew to the L2 Gateway and conduct lunar missions at the very least ....