kraisee - 23/12/2007 1:36 AMQuotemeiza - 22/12/2007 7:16 PMQuoteclongton - 21/12/2007 9:02 PMAs for the more “mundane” tasks, your approach appears to leave them to the unaltered Atlas and Delta launch vehicles. DIRECT does exactly the same thing! There are many things in VSE implementation that do not require heavy lift, and we prefer to assign those things to the standard Atlas and Delta families, because those launchers are a much better fit. Emphasis mine.It's not a requirement, but a choice.That's all any "requirement" is though - a choice. We could "choose" to do a Lunar program or not. The "requirement" is to do it currently. We could choose to do such missions in one flight, two flights, 4 flights or 56 flights. The current choice/requirement is 2 flights.
meiza - 22/12/2007 7:16 PMQuoteclongton - 21/12/2007 9:02 PMAs for the more “mundane” tasks, your approach appears to leave them to the unaltered Atlas and Delta launch vehicles. DIRECT does exactly the same thing! There are many things in VSE implementation that do not require heavy lift, and we prefer to assign those things to the standard Atlas and Delta families, because those launchers are a much better fit. Emphasis mine.It's not a requirement, but a choice.
clongton - 21/12/2007 9:02 PMAs for the more “mundane” tasks, your approach appears to leave them to the unaltered Atlas and Delta launch vehicles. DIRECT does exactly the same thing! There are many things in VSE implementation that do not require heavy lift, and we prefer to assign those things to the standard Atlas and Delta families, because those launchers are a much better fit.
This is the main "requirement" which drives the "need" for Heavy Lift in the equation - because just two 25 ton launchers don't cut sufficient mustard - by anyone's measure.Everything in the program is about choices.
We "choose" whether to provide contingency safety equipment for crews or not. Shuttle currently doesn't offer much in the way of such equipment, but Orion is "required" to offer a whole lot more. This was because CAIB made the official recommendation to not compromise the crew launch vehicle for any reason; cost, performance, schedule or anything. NASA currently "chose" that this recommendation would form the backbone of the "requirements" for the new program. That led them (amongst other thing) to the two-stage, two-engine'd Ares-I - although that particular poor technical "choice" appears to have now, 2 years later, come back to bite them on the butt.There are many other technical, economic, schedule and political "requirements" too. Many. It is a political requirement to keep the Shuttle Workforce as intact as possible. It is a technical requirement to not send the Orion spacecraft to the Lunar surface. There is a schedule requirement to service ISS as soon as possible after Shuttle retires - with a Presidential directive to do so within 4 years - by the end of 2014, but which NASA is finding technically and economically difficult to comply with. All of these are requirements, and choices.There are three main issues at work in favour of all SDLV solutions which are currently keeping EELV out of the equation...1) Political. There is a lot of profit (mostly in terms of employment producing local economic benefit) to be made by many states who currently support the Space Shuttle Program. Also there are weapon system cost benefits to the DoD through the sharing of costs for Solid propellant systems. Ditching any of that architecture has lots of job repercussions in many districts and the politicians representing these areas are strongly against any options proposing to do that. Many of these folk are on the appropriate committees too, so their opinions hold quite a bit of power.2) "Brain Drain". NASA and the Contractor base lost a most of the talent after Apollo. They were unable to get the bulk of the talent back again when Shuttle was eventually ready. It took the agency more than a decade to rebuild a similar level of skill within the program - though to this day there are still gaping holes with regard to Lunar missions. NASA is 100% firmly against any similar thing happening now during this transition. The Contractor networks are also bringing significant pressure to bear to make sure they too don't lose their current funding base provided by Shuttle. They are also strongly against the idea of having to delete whole departments of knowledgeable staff from their ranks.2b) Re-creating the Internal Skill-base within NASA. NASA has, since Mike Griffin took the reins, spent a great deal of effort rebuilding internal capabilities like they had during Apollo - instead of always relying upon the contractors. Go off and examine for yourself any of NASA's Budget documents from the last few years to get a feel for exactly how seriously the agency is about this. NASA faced decades of criticism for relying upon the contractors for all of its technical skills. It has decided to change that, and Congress (and I, for what little it is worth) support this. Like it or not, there is no mistaking that NASA administration is making *vast* efforts to ensure that the skill set for Constellation is not placed entirely in the contractors hands. NASA wants the field changed and the skills and knowledge to be retained in-house.3) Technical. From a purely technical basis, NASA wants to reduce the number of flights required for the missions to the minimum possible. The additional launches, additional dockings and additional logistics surrounding missions with 3 or more flights are considered "excessive" with current data in-hand. Agree or not, the ESAS Report argued its case and NOBODY has ever presented a case against this assessment. There's lots of "talk", but N*O*T*H*I*N*G in writing to indicate this may be wrong. NASA still stands by those arguments and has no competing justification against it.3b) Further, I have been able to confirm independently the cost issues surrounding multi-launch options using EELV's. Given all the data I have been able to uncover, I feel there *are* critical issues with a "many small flights" vs. any 2-launch solutions. Some don't wish to believe the cost data I've offered, but there really doesn't appear to be any way to discourage that - the Internet has always had folk like that, its just a fact of life. If the hard accounts are not enough to convince people, I don't think its my place to try to convince them.EELV's won't get a look-in until their proponents make clear precisely how they intend to address these three issues. They can't get political support until they resolve issue #1. They won't get NASA's support until they address both issues #2 and #3. Without political and agency support the EELV's get no traction at all. It's up to their proponents to change this or not. Right now, they haven't actually tried, so it's no surprise to me that they haven't made any ground. Burying heads in the sand and ignoring this isn't going to change anything either.As for Heavy Lift reasoning: If cost isn't enough, I would suggest that spacecraft footprint and landing stability are major issues for a lunar lander and I have yet to see the slightest evidence that an Apollo-LM style solution is in any way "worse" than Lockheed's concepts - which appear to be the only other game in town at present. Until I see at least one independent analysis of the Lockheed designs I remain unconvinced of there being any 'advantage' at all over an already-proven concept - especially as their own document says it doesn't represent a good final configuration. Therefore I believe it very sensible for NASA to issue the current "requirement" to duplicate Apollo's proven success - albeit larger. There's a long way to go before an LM-style concept arrangement is going to be considered "better". So with a large Apollo-style lander that means a form factor at least 7.4m diameter, maybe 8.7m. *That* drives the physical size "requirement" for a launcher too. I have yet to see any Atlas-V or Delta-IV with a 10m shroud proposal.And another issue which EELV proponents conveniently ignore is Mars.500 ton missions will never lend themselves to 25 ton lift architectures. We can't seriously plan to launch another "ISS" sized spacecraft in order to go to Mars!!! That's just plain stupidity IMHO and I'm not even factoring in the idea of fully automated assembly (yeah, right) or the CLV flights needed for assembly.Instead, we have some real political will right now - for the first time in 30 years - to build a new Heavy Lifter which we can use for all future Lunar and Mars missions. We also have a Heavy Lifter right now - Shuttle - which can be modified to suit the new purpose for not a very vast cost if done correctly (Ares-I + Ares-V is *not* cost effective IMHO though).If we squander this golden opportunity it will be at the very serious risk of *never* making it to Mars while watching other nations make those moves around us. It is my personal opinion that ignoring or missing this single opportunity would be the worst mistake in the US space program since abandoning Apollo - even including the Challenger and Columbia mistakes.Ross.
meiza - 25/12/2007 6:01 PMI want to create a spacefaring civilization with routine launches by many organizations. Reusable launch vehicles evolving to become ever better, big markets and low cost of space transportation. Lots of tries, inevitable setbacks and unexpected successes. Not a designed glorious future, but a future with lots of opportunities. Mankind will become space faring when launch to LEO is cheap, reliable and flexible enough. Apollo was a false start, a great achievement but too unsustainable in the way it was done. It was fundamentally an impatient architecture (the requirement was a recipe for that of course). As was the shuttle, trying to design something so ambitious right off the bat. It has done great things too, but perhaps those could have been possible with much less cost, and then we could be even further along now.You feel that this is a critical juncture in history when a single launch system will be created that will be in use for many many decades to come. NASA will be the only organization with any serious business in space. There is no hope for much advances except improving NASA's current designs. NASA will have to go it alone. We have to design almost everything now, just leave some upgrade margins for the future. Apollo was great but it used too little money so it was cut, if only they had kept spending... And shuttle, I don't know what you really think about it.
SirThoreth - 26/12/2007 1:02 AM"Light" reusable launchers aren't going to give you a sustainable infrastructure in space, any more than using Cessna 172s and Ford Ranger pickups will allow the kind of infrastructure and transportation that jumbo jets and semi tractor-trailers do.Throwing away a heavy lift vehicle may not seem to make much sense at first, either, but, then, there's a key difference: jumbo jets and semi trucks move cargo two ways. Launch vehicles don't.
mike robel - 25/12/2007 9:32 PMI have a couple - three observations, that may or may not be relevant.First is, I have become a sort of convert to Direct Ascent to the moon or mars. It seems to me that, at least with unmanned vehicles, there could be more mass delivered to the lunar surface than with the other architectures. Depots and orbital assembly add unnecessary complexity and risk to the mission, given the current technology. Many of these risks are reduced with direct ascent and robotic landing of their payloads on the moon. After the precursor payloads are in place, you can follow up with manner spacecraft followiong a variety of mission modes. We are, after all, sending unmanned probes to every planet without the need for orbital assembly, fuel depots, and direct injection by relatively low capability boosters such as the Delta II.Second, as Stalin said, "Quantity has a quality all its own." Using a series of launchers to send many payloads to the moon or mars gives us some savings on total program costs. So, using EELVs to deliver standard payloads to the lunar surface at monthly intervals would give us some economy lf scale - somewhat analgous to the barges and covered wagons of the American West, which were not generally used on two way journeys, but were broken down for other uses once they reached their destinations. These smaller craft would be supplemented by Heavy lift payloads used to land manned habitats. The pioneers/colonists had a different environment in that they could live off the land (as opposed to space pioneers - at least initially) and the ships/railroads were the analogies of Heavy Lift able to deliver great quantities of material to the colonists.Third, I was hopeful that the VSE would help us overcome what I (borrowed from Martin Caidan) call the Viking Syndrome. This is based on the observation that the Vikings had the technology to send some initial voyages to the New World, but lacked the logistical follow through to ultimately sustain them, there is evidence that the onset of the Little Ice Age caused them to abandon their outposts and perhaps this exagerated the shortcomings of their logistical train.What we clearly need is a plan that utilizes manned and unmanned systems of various capabilities, delivering sustainable amounts of supplies to the target worlds, until such time that those colonies can become self-sustaining through ISRU. I believe that HLVs are an integral part of this plan, but they need to be supplemented by the very capable EELV fleet. Just as the USAF does not rely on a single type of bomber, fighter, or transport, neither should the nation be committed to a course of action that only uses one type of booster and spacecraft.
meiza - 26/12/2007 12:34 PMThere can be no realistic technical and enlightened discussion of architectures as long as the heavy lift camp maintains that the heavy lift is absolutely necessary as an axiom and will not discuss technical ways to solve the problem of lunar exploration and infrastructure development.
clongton - 26/12/2007 5:43 PMQuotemeiza - 26/12/2007 12:34 PMThere can be no realistic technical and enlightened discussion of architectures as long as the heavy lift camp maintains that the heavy lift is absolutely necessary as an axiom and will not discuss technical ways to solve the problem of lunar exploration and infrastructure development.Heavy lift already solves the infrastructure development part of that and does it more economically than any other known - existing - method. There are technical solutions to using less capable launch vehicles, but at the cost of complexity, expense and usable life of the delivered payload. Numbers don't lie, and that's what the numbers tell us.
meiza - 26/12/2007 2:44 PMNumbers lie all the time. It doesn't make stuff automatically true if one throws a number from the hat.But thanks for acknowledging that other methods besides heavy lift are possible too. (No sarcasm.)
meiza - 26/12/2007 6:13 PMSo, you looked at propellant depots with EELV:s and found them infeasible?
And you applied the 90% of costs when production rate is doubled paradigm, which surely is just a general rough rule of thumb for some manufacturing industry and could even be just a myth. I don't think you used any insight from inside the EELV organizations, at least according to the EELV people over here on this forum.And you slapped some 500 million of fixed costs and a few billion of STS infra demolition costs... All the while estimating very low costs for Direct.And then you pretend as if your numbers are somehow so very exact.I just don't have the time or even motivation for such efforts of obvious fluff. I'm an engineer, not a sales person drawing pretty pictures and weaving tables with decimals of *very rough estimates*.In essence, assuming a near constant per-unit price for EELV:s (or any future launcher) no matter the flight rate, and a fabulously low price for Direct (no future changes) of course makes Direct look the best alternative.The tables and graphs can be useful as drafts and estimates but saying that "look at this, numbers don't lie" is, well, lousy.
Eh, if you are a believer in paper rocket marketing presentations, then use the cheap magical Falcon 9 heavies (was a regular F9 35 million?) and the solar system starts to open up a little better... Add in stage refurbishment at, say, 2 million (from the hat) cost per flight for 10 reuses and you get further big drops. (If anyone is in doubt, I don't really believe in those numbers.)