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SpaceX Dragon spacecraft for low cost trips to the Moon.
On Oct 8, 8:26*am, Robert Clark wrote:
On Oct 7, 7:46*am, Alan Erskine wrote: On 6/10/2010 6:44 PM, Robert Clark wrote: On Oct 4, 8:00 pm, Alan *wrote: On 5/10/2010 4:53 AM, Robert Clark wrote: * *The Orion spacecraft and Altair lunar lander intended for a manned Moon mission are large craft that would require a heavy lift launcher for the trip. However the Dragon spacecraft is a smaller capsule that would allow lunar missions with currently existing launchers. The idea for this use would be for it to act as a reusable shuttle only between LEO and the lunar surface. This page gives the dry mass of the Dragon capsule of 3,180 kg: Not that much smaller and not that much lighter - Orion's CM was/is only about 4.5 tonnes - it's the SM with all the propellant that makes it heavy, and Dragon's only got to return from LEO, so it's much less propellant-hungry than a Lunar mission (LOI, Earth return etc). * Do have a ref for that? This page gives the mass of the capsule as 9,500 kg: Orion (spacecraft). http://en.wikipedia.org/wiki/Orion_%28spacecraft%29 * Bob Clark This page tells mohttp://en.wikipedia.org/wiki/SpaceX_Dragon-With a payload of 6 tonnes, the total "CM" mass is 10.2 tonnes; so it's heavier than Orion. *This is actually the fully loaded mass. Remember the Dragon is to be used both for crew transport and for cargo transport. The max 6 tonnes payload mentioned is for when it used for cargo transport. Of course it doesn't have to carry any cargo besides, crew provisions, when used for manned flights. That's because the crew IS the cargo in that configuration along with their provisions as well as their other gear. I'm a bit skeptical about this comparison since it neglects the amount of structure required to keep the crew safe from radiation while going through the Van Allen Radiation Belt as well as through deep space to the Moon, and for the duration the capsule is in orbit. Also how much of an increase in size will the service module on a Dragon need to accomadate fuel and supplies for the greater duration as well as the Lunar braking manuever, and the burn to get back to Earth. How much bigger of an engine for these manuevers? Is Musk's hype about the Dragon heat shield correct, or will that need additional material as well? How much extra mass will the launch escape system add? If the Centuar is to be reusable, how much extra mass to the structure does that add? Your recovery scenario glosses over this aspect, including recovery methods. -Mike |
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SpaceX Dragon spacecraft for low cost trips to the Moon.
On 10/15/2010 3:04 PM, Mike DiCenso wrote:
That's because the crew IS the cargo in that configuration along with their provisions as well as their other gear. I'm a bit skeptical about this comparison since it neglects the amount of structure required to keep the crew safe from radiation while going through the Van Allen Radiation Belt as well as through deep space to the Moon, and for the duration the capsule is in orbit. That might be workable; the Apollo CM's hull was thick enough to provide adequate radiation protection while passing through the radiation belts, due to speed of the passage at the injection speed for TLI and the structural strength needed for ascent g's and those experienced during reentry. At least in the Constellation plan where the Orion stayed unmanned in lunar orbit while the Altair carried the crew to the surface for a month-long stay*, the trick was making the very lightweight Altair have a reasonable amount of radiation protection if there was a solar storm while it was on the surface. *As to what the Altair's crew was going to be doing during the two weeks of lunar night is anyone's guess. I imagine you could take the rovers out with headlights on them, but considering that light doesn't get diffused in a vacuum, that sounds like a really good way to drive over the edge of a 10' cliff that you thought was a minor dip in the terrain. :-D Pat |
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SpaceX Dragon spacecraft for low cost trips to the Moon.
On Oct 16, 1:32*am, Pat Flannery wrote:
On 10/15/2010 3:04 PM, Mike DiCenso wrote: That's because the crew IS the cargo in that configuration along with their provisions as well as their other gear. I'm a bit skeptical about this comparison since it neglects the amount of structure required to keep the crew safe from radiation while going through the Van Allen Radiation Belt as well as through deep space to the Moon, and for the duration the capsule is in orbit. That might be workable; the Apollo CM's hull was thick enough to provide adequate radiation protection while passing through the radiation belts, due to speed of the passage at the injection speed for TLI and the structural strength needed for ascent g's and those experienced during reentry. At least in the Constellation plan where the Orion stayed unmanned in lunar orbit while the Altair carried the crew to the surface for a month-long stay*, the trick was making the very lightweight Altair have a reasonable amount of radiation protection if there was a solar storm while it was on the surface. *As to what the Altair's crew was going to be doing during the two weeks of lunar night is anyone's guess. I imagine you could take the rovers out with headlights on them, but considering that light doesn't get diffused in a vacuum, that sounds like a really good way to drive over the edge of a 10' cliff that you thought was a minor dip in the terrain. :-D In regards to the Dragon being able to perform BEO missions, Elon Musk, and I presume the SpaceX engineers, believe it can. Elon mentioned the success of the heat shield on the Dragon reentry about 8 and 1/2 minutes into Wednesday's post flight press conference. He said the Dragon heat shield was designed to survive even worst case Mars and lunar return trajectories, and from the performance during the flight SpaceX is confident it could be used for that purpose. He then said this opens up possibilities for the Dragon as a potential replacement for the Orion capsule, presumably for circumlunar missions: NASA and SpaceX Press Conference After Falcon 9 Launch with Dragon Aboard Part 1. http://www.youtube.com/watch?v=a9MaFqZUQkE In this portion of the post flight conference about 4 minutes in, in response to a question Elon says anything the Orion spacecraft can do the Dragon can do and actually more since the Dragon heat shield is sufficient for even Mars return trajectories. And therefore he says for any missions being considered by NASA for the Orion capsule, the Dragon capsule should also be considered: NASA and SpaceX Press Conference After Falcon 9 Launch with Dragon Aboard Part 4. http://www.youtube.com/watch?v=WOfj-k_Irpc Bob Clark |
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SpaceX Dragon spacecraft for low cost trips to the Moon.
On Dec 12, 4:37*am, Robert Clark wrote:
.... *In regards to the Dragon being able to perform BEO missions, Elon Musk, and I presume the SpaceX engineers, believe it can. Elon mentioned the success of the heat shield on the Dragon reentry about 8 and 1/2 minutes into Wednesday's post flight press conference. He said the Dragon heat shield was designed to survive even worst case Mars and lunar return trajectories, and from the performance during the flight SpaceX is confident it could be used for that purpose. He then said this opens up possibilities for the Dragon as a potential replacement for the Orion capsule, presumably for circumlunar missions: NASA and SpaceX Press Conference After Falcon 9 Launch with Dragon Aboard Part 1.http://www.youtube.com/watch?v=a9MaFqZUQkE *In this portion of the post flight conference about 4 minutes in, in response to a question Elon says anything the Orion spacecraft can do the Dragon can do and actually more since the Dragon heat shield is sufficient for even Mars return trajectories. And therefore he says for any missions being considered by NASA for the Orion capsule, the Dragon capsule should also be considered: NASA and SpaceX Press Conference After Falcon 9 Launch with Dragon Aboard Part 4.http://www.youtube.com/watch?v=WOfj-k_Irpc Another major consideration is the reduced development costs SpaceX has been able to accomplish compared to the usual way of doing things. In this part of the post flight news conference a questioner notes the development cost for Falcon 9, which he implies includes that of the Dragon, was in the range of $400 million, while for the Orion capsule, over $4 billion: NASA and SpaceX Press Conference After Falcon 9 Launch with Dragon Aboard Part 4. http://www.youtube.com/watch?v=WOfj-k_Irpc The comparison might be a little unfair in that SpaceX has said it might take an additional $300 million to man-rate the Falcon 9 and Dragon capsule, mostly due to an escape system and flight tests. But still even then your're talking about multiple times more in development costs by the "old space" companies. Bob Clark |
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SpaceX Dragon spacecraft for low cost trips to the Moon.
On Dec 12, 4:45*am, Robert Clark wrote:
On Dec 12, 4:37*am, Robert Clark wrote: ... *In regards to the Dragon being able to perform BEO missions, Elon Musk, and I presume the SpaceX engineers, believe it can. Elon mentioned the success of the heat shield on the Dragon reentry about 8 and 1/2 minutes into Wednesday's post flight press conference. He said the Dragon heat shield was designed to survive even worst case Mars and lunar return trajectories, and from the performance during the flight SpaceX is confident it could be used for that purpose. He then said this opens up possibilities for the Dragon as a potential replacement for the Orion capsule, presumably for circumlunar missions: NASA and SpaceX Press Conference After Falcon 9 Launch with Dragon Aboard Part 1.http://www.youtube.com/watch?v=a9MaFqZUQkE *In this portion of the post flight conference about 4 minutes in, in response to a question Elon says anything the Orion spacecraft can do the Dragon can do and actually more since the Dragon heat shield is sufficient for even Mars return trajectories. And therefore he says for any missions being considered by NASA for the Orion capsule, the Dragon capsule should also be considered: NASA and SpaceX Press Conference After Falcon 9 Launch with Dragon Aboard Part 4.http://www.youtube.com/watch?v=WOfj-k_Irpc Another major consideration is the reduced development costs SpaceX has been able to accomplish compared to the usual way of doing things. In this part of the post flight news conference a questioner notes the development cost for Falcon 9, which he implies includes that of the Dragon, was in the range of $400 million, while for the Orion capsule, over $4 billion: NASA and SpaceX Press Conference After Falcon 9 Launch with Dragon Aboard Part 4.http://www.youtube.com/watch?v=WOfj-k_Irpc The comparison might be a little unfair in that SpaceX has said it might take an additional $300 million to man-rate the Falcon 9 and Dragon capsule, mostly due to an escape system and flight tests. But still even then your're talking about multiple times more in development costs by the "old space" companies. * Bob Clark- Hide quoted text - - Show quoted text - this makes nasa irrevelant, which is sad but perhaps necessary. get nasa out of the way......... |
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SpaceX Dragon spacecraft for low cost trips to the Moon.
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SpaceX Dragon spacecraft for low cost trips to the Moon.
On Dec 12, 8:27*am, " wrote:
this makes nasa irrevelant, which is sad but perhaps necessary. You have never played videogames? There should be as many space service providers as, say, radio stations or local bus lines, or even internet domains! It is the way knowledge and capital tend to accumulate when you start with a successful commercial-technological base. You can see it in simulators, I mean, videogames (was the army spending billions of budget into GAMES?). NASA can reaccomodate, but who was the IMBECILE (60 IQ or less) who decided that all internet content be given under DUMPING? I am a fan of space pictures I find for free everywhere; even NASA can find a way to turn some *products* into commercial ventures then act as compensation chamber/regulatory body... though I still remember a recent magazine announcing a new spatial venture with an engine development picture I remember from my early childhood in the seventies! (Automatic debris collection, anyone?) Danilo J Bonsignore |
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SpaceX Dragon spacecraft for low cost trips to the Moon.
On 12/13/2010 5:29 AM, David Spain wrote:
wrote: this makes nasa irrevelant, which is sad but perhaps necessary. get nasa out of the way......... Bob, I disagree; it doesn't make NASA irrelevant. But what it enables is a different role for NASA. NASA can move into the roles of consulting and facilitator more than a program office. Oh God, that's the last thing they need. Yoyodyne Industries is interested in developing a new upper stage for the Delta 4; and NASA sends them a consultant to help them out - the consultant bears an uncanny resemblance to Groucho Marx: "Are you our NASA consultant?" "I don't know, who's asking? You aren't with any congressional investigating committee, are you?" "No." "Then I'm your NASA consultant." "Well, we sent you our basic concept outline, what did you think of it?" "I thought it had some basic problems, like the fact it exists for instance...shred all copies of it, and burn the remains." "Why?" "The whole thing must never be seen by the public! You have outrageous and completely un-American concepts in that report! Why, if you do things that way you could bankrupt the whole aerospace industry. Children will starve because of what you have done...do you want that on your conscience? Starving children crawling around on the floor, too weak to stand up and drop dead like men? I think not!" "Okay, what's wrong with it in detail?" "I don't even know where to start...where are the multiple design revisions?" "What?" "You must redesign it at least ten times before you even consider building it, with each redesign correcting some flaw that somehow got through the prior redesign, like in your case maybe forgetting to put engines on the upper stage in the original design, or specifying that it should be built using metric iron stove bolts in redesigns #2-8. Play that right and you can make even the simplest things take years to build and assure continued work for your design engineers. We have a little shrine built to Space Station Freedom in this regard, as by the time we had completed the last redesign, we had spent all the money that was going to be used to actually build it. There were giants in those days, designers of renown!" "Well this concept is fairly straight-forward and uses off-the-shelf parts." "You have damned yourself twice in that one sentence! Nothing is straight-forward in rocketry! Do you remember how long it took us to get the Shuttle's toilet to work right? And that was just a crapper, not an upper stage. "Off-the-shelf parts" are a sure road to disaster, as they are never optimized for the new design. Who cares if the development of new parts cost 1,000 times as much as using existing parts if they up performance by 1%? Even better is to modify off-the-shelf parts into something completely unrecognizable, as this lets you claim you are saving taxpayer money! Do you realize that the Shuttle SRB's are highly modified Estes "D" engines? Or that its ET started out as a "slightly enlarged" B-58 Hustler drop tank? Don't even get me started on where the orbiter main engines came from, let's just say that their ancestors powered many a racer in the Indy 500. With luck you can spend at least three times as much modifying stock parts as you would building entirely new ones." "The idea is to spend as much money as possible?" "OF COURSE THE IDEA IS TO SPEND AS MUCH MONEY AS POSSIBLE! This is to be sold to the government on a cost-plus basis! If it costs a hundred million dollars to build it, and you get a 10% profit on it, that's only ten million dollars - chicken feed! Children crawling around on the floor trying to subsist on a diet of dust and dead cockroaches! But now...if it cost, a _billion_ dollars to build, you are getting one hundred million dollars! Now _that's_ the way to do business! The stockholders are happy, the employees can feed their starving children T-bone steaks, and you get a knock-out trophy wife and three Mistresses on the side!" "But it's designed to be more economical than the existing stage; that's its selling point..." "More economical or _cheaper_? Do you think the government wants some sort of crappy upper stage like you would find at a Dollar Store? No, they will be highly suspicious of anything that costs less than what they are currently using. You must be creative in ways to up its costs to what the government is expecting - why gold-plate things when you could make them out of solid gold? Jeweled bearings on the turbopump will make it run smoother, and if those jewels were diamonds, they would be almost completely wear-free. Even the initial bid should be only slightly less expensive and slightly more capable than the existing competition, with the promise that by the time it enters service it will cost around twice what was stated, be years behind schedule, and not be able to do what was promised. Take a look at that Lockheed F-35B program; that's the way you do it!" "But, they'll just cancel it then." "No, no, NO! They _can't_ cancel it! Because you were smart enough when the government signed the contract for its design and manufacture to make sure the government's penalty fee if they canceled it would be more than the profits to be realized if it was actually put into service, and you would make a net profit! Watch the movie "The Producers" sometime; that's how you do it! This upper stage could be your very own "Springtime for Hitler". You are that big marlin that has got the Old Man Government's hook in its mouth, and is dragging him straight out to sea! He doesn't dare cut and run, and by the time its all over it will be him, not you, that gets fed to the sharks. Now, that's the American Way! I hope I've been of help...but there's one last secret I'm going to confide to you." "What, what?" "There is nothing greater than having an "independent" analysis done of your project by an outside group that will endorse its merits. Remember how the Mathematica Study thought that the Space Shuttle was going to cut launch costs?" "Yes." "Well, if you phrase the question to an independent analysis group correctly, they will always come to the conclusion you want them to. In the case of Mathematica it was casually mentioning that if they didn't endorse NASA building the Shuttle, tens of thousands of NASA employees would be out of work, and many of them were avid hunters who owned high-powered rifles with telescopic sights on them. It changed the whole equation." ;-) Pat |
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SpaceX Dragon spacecraft for low cost trips to the Moon.
Pat Flannery wrote:
On 12/13/2010 5:29 AM, David Spain wrote: wrote: this makes nasa irrevelant, which is sad but perhaps necessary. get nasa out of the way......... Bob, I disagree; it doesn't make NASA irrelevant. But what it enables is a different role for NASA. NASA can move into the roles of consulting and facilitator more than a program office. Oh God, that's the last thing they need. Yoyodyne Industries is interested in developing a new upper stage for the Delta 4; and NASA sends them a consultant to help them out - the consultant bears an uncanny resemblance to Groucho Marx: .... :-D Pat, Whatever you are using, I want some.... ;-) Dave 'John YaYa' Spain |
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