Hmmm... Shoulda posted in this thread...So if everyone is so enamoured with analogies, how about extending the petrol/gas meme to outer space? It looks like space isn't going to happen anytime soon till big business gets aboard(sic). How about letting, say, the big oil companies/OPEC or some energy conglomerates have an exclusive to provide the first and only - for a while - gas'n'go fuel depot in LEO? If there's anything these guys can do - its the big single mega projects - transcontinental gas lines, deep shore wells, etc. A space depot would be a natural for them. Probably at a small fraction(sic) of their advertising budget - the goodwill generated would be better than anything they are doing now - sort of reverse the trend of being seen as the 'bad' guys.
I don't agree that the oil companies (or OPEC) have the technical ability to set up space propellant depots, but they do have the financial and management ability to handle very large engineering projects: the Alaska Pipeline. In todays $, $30 BILLION in just 3 years, of their money, not the taxpayer's, in some of the most inhospitable environments on Earth. Very cold, kinda like Mars. These guys are real MEN with real guts. To be honest, Bruce Willis types. Gee, I wonder...
Quote from: StarGeezer on 08/27/2009 05:34 pmHmmm... Shoulda posted in this thread...So if everyone is so enamoured with analogies, how about extending the petrol/gas meme to outer space? It looks like space isn't going to happen anytime soon till big business gets aboard(sic). How about letting, say, the big oil companies/OPEC or some energy conglomerates have an exclusive to provide the first and only - for a while - gas'n'go fuel depot in LEO? If there's anything these guys can do - its the big single mega projects - transcontinental gas lines, deep shore wells, etc. A space depot would be a natural for them. Probably at a small fraction(sic) of their advertising budget - the goodwill generated would be better than anything they are doing now - sort of reverse the trend of being seen as the 'bad' guys.I don't agree that the oil companies (or OPEC) have the technical ability to set up space propellant depots, but they do have the financial and management ability to handle very large engineering projects: the Alaska Pipeline. In todays $, $30 BILLION in just 3 years, of their money, not the taxpayer's, in some of the most inhospitable environments on Earth. Very cold, kinda like Mars. These guys are real MEN with real guts. To be honest, Bruce Willis types. Gee, I wonder...Stanley
Quote from: adamsmith on 08/27/2009 07:52 pmQuote from: StarGeezer on 08/27/2009 05:34 pmHmmm... Shoulda posted in this thread...So if everyone is so enamoured with analogies, how about extending the petrol/gas meme to outer space? It looks like space isn't going to happen anytime soon till big business gets aboard(sic). How about letting, say, the big oil companies/OPEC or some energy conglomerates have an exclusive to provide the first and only - for a while - gas'n'go fuel depot in LEO? If there's anything these guys can do - its the big single mega projects - transcontinental gas lines, deep shore wells, etc. A space depot would be a natural for them. Probably at a small fraction(sic) of their advertising budget - the goodwill generated would be better than anything they are doing now - sort of reverse the trend of being seen as the 'bad' guys.I don't agree that the oil companies (or OPEC) have the technical ability to set up space propellant depots, but they do have the financial and management ability to handle very large engineering projects: the Alaska Pipeline. In todays $, $30 BILLION in just 3 years, of their money, not the taxpayer's, in some of the most inhospitable environments on Earth. Very cold, kinda like Mars. These guys are real MEN with real guts. To be honest, Bruce Willis types. Gee, I wonder...StanleyNot quite true, while a large portion of the construction was done by private firms, the government was heavily involved in arranging the land rights necessary for the pipeline. It took cooperation between the two, gov't and business, to get the pipeline done.
http://www.lpi.usra.edu/publications/reports/CB-1106/wash01.pdfStanley
Quote from: adamsmith on 08/24/2009 03:20 amhttp://www.lpi.usra.edu/publications/reports/CB-1106/wash01.pdfStanleyThis uses the magsail. I first saw this described by Zubrin.Has this (magasail for sailing around the solar system) been discussed in this forum and could someone provide a link?
Quote from: kraisee on 08/25/2009 08:33 pm .I am including the costs for the launches below.Ross.
.I am including the costs for the launches below.Ross.
With all the discussion recently, let me take a moment to try to clarify the Depot architecture decisions which we have made for DIRECT.There is much debate about using an all-EELV-class approach. What this would require, is approximately 9 launches for each mission. Assuming a combination of 20mT and 25mT vehicles the following approach is hypothetically possible (though only if you choose to completely ignore the volume/diameter issues entirely):1 Orion (fueled) -- Heavy2 Lander Ascent Stage (fueled) -- Intermediate3 Lander Descent Stage (dry) -- Heavy4 EDS (mostly dry) -- Intermediate5 Fuel for Descent Stage -- Intermediate6 Fuel for EDS -- Intermediate7 Fuel for EDS -- Intermediate8 Fuel for EDS -- Intermediate9 Fuel for EDS -- IntermediateThis architecture certainly requires the use of Propellant Transfer technologies and would almost-certainly require a full Depot to be deployed as part of the baseline Critical Path to success.Of these 9 launches, the first 4 in that list are all mission critical and the loss of any one would result in an LOM situation. The latter 5 launches are somewhat "interchangable" so there is "Partial Redundancy" possible there. It's not too bad, but the logistics and the necessity to coordinate the launch of 4 of those vehicles perfectly in support of each mission, plus the constant fuel deliveries as well, makes it a very demanding logistical nightmare.
While this is definitely one way to do things, it's far from the optimum for a depot-centric architecture. If you're going to do an LEO depot, making a second copy and sending it to L1/L2 makes a lot of sense (since it allows both of them to be small single-EELV-launch depots that don't require any on-orbit assembly). With such a system, you don't need a lander descent stage anymore. It is possible to refuel a Centaur-sized EDS in L1/L2, and have it do the Lx-to LUNO burn and a large chunk of the descent burn. The lander DV is now quite a bit less than was needed for ESAS, and you can have it be a single-stage system, which tends to be more mass efficient for landers. The "Orion" can also be a lot smaller with such an architecture, because you don't need anywhere near as much delta-V to return to LEO, especially if you stage out of L2.Sure, the logistics gets more involved, and I'll have to run the numbers on how many launches you need to do an ESAS-equivalent mission, but my point here was just to mention that a depot-centric architecture will not look like an HLV-centric architecture with depots tacked onto the side. That's black-aluminum thinking.~Jon
OK, do I understand this correctly?
Of course, there are additional fueling flight fueling the depots...
Quote from: DonEsteban on 08/28/2009 01:46 pmOK, do I understand this correctly?That's pretty close. My personal favorite nuance though is that if you top the Centaur back up all the way before doing the LX to LUNO burn, there's actually enough fuel leftover after staging for it to do a burn to return to LUNO and then to LX. Reusing a stage that's only been used in-space, has not been contaminated by the lunar surface environment, and doesn't have to deal with the hellish reentry environment should be substantially easier.Also you forgot to mention the step where you ship the actual lander out. It would likely fly separately from the capsule, and depending on the dV split between the two, might even be capable of self ferrying....snip...~Jon