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High-flight rate Medium vs. New Heavy lift launchers
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#12
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High-flight rate Medium vs. New Heavy lift launchers
Finally, there is the issue of what expertise we lose when we
shut down a heavy lift capability (Saturn V, Energia, Shuttle). Certainly we don't mind losing the cost of the standing army, but are we going to lose the facilities for large fuel tanks or recoverable strap-ons? - Cris Fitch San Diego, CA http://www.orbit6.com/ It might be worthwhile to mothball the tooling for the big shuttle tanks. The case for the big solids is less clear, since one alternative is using Atlas V cores as boosters. When the need develops for a very large launcher, one option might be an in-line launcher with three RS-68 engines beneath a shuttle derived tank, and Atlas V cores strapped on as needed. Wih six of them, you should be able to get a pretty impressive payload. Will McLean |
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High-flight rate Medium vs. New Heavy lift launchers
On 26 Jan 2004 09:00:22 -0800, in a place far, far away,
(ed kyle) made the phosphor on my monitor glow in such a way as to indicate that: SpaceX hasn't proposed a heavy lift vehicle, which is required for this application. No, it's not. It's desired, by some, but it's not required. |
#14
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High-flight rate Medium vs. New Heavy lift launchers
Damon Hill wrote in message . 132...
"Dholmes" wrote in : Increasing the thrust of the second stage with either a MB-60 or RL-60 and adding a third stage is IMO a must. This appears to be Boeing's thinking, since they are proposing stacking two upper stages, most likely using single MB-60s. Two MB-60s on a single stage would probably require increasing tank volume to get full benefit. The Delta 4 payload guide mentions a Star 48B third stage for planetary missions, but does not give performance figures. http://boeingmedia.com/images/one.cf...8856&release=t Interesting. Note that a fully fueled Delta IV 5-meter diameter second stage weighs nearly 31 metric tons (less than 4 tons empty), several tons in excess of what Delta IV-Heavy is reported to be capable of boosting to low earth orbit. The logical approach would be to upgrade Delta IV-Heavy enough to be able to put 31 tons into LEO so that these stages could be orbited fully fueled. This two-stage plus CEV stack, which appears capable of translunar insertion, would then require three Delta IV- Heavy launches. One or two more launches would apparently be needed to assemble a lunar lander and its insertion stage, perhaps sent separately from the CEV. - Ed Kyle Boeing also appears to be proposing nuclear-thermal propulsion in this image: http://boeingmedia.com/images/one.cfm?image_id=8864 I haven't seen Boeing's proposed solar-thermal stage mentioned, perhaps its thrust is too low despite excellent Isp. Getting significantly more out of the Delta 4 Heavy configuration with existing launch facilities might mean something more radical as converting the two strap-ons to LOX/kero and using RD-180 or a new 1 megapound kero engine being developed on the latter's technology, and adapting the core stage to altitude ignition, as with Titan 3/4. Benefits to unmanned planetary exploration with these improvements, too. I wonder how much would be needed to launch that long-duration heavy rover to Mars? --Damon |
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High-flight rate Medium vs. New Heavy lift launchers
(Rand Simberg) wrote in message . ..
On 26 Jan 2004 09:00:22 -0800, in a place far, far away, (ed kyle) made the phosphor on my monitor glow in such a way as to indicate that: SpaceX hasn't proposed a heavy lift vehicle, which is required for this application. No, it's not. It's desired, by some, but it's not required. To clarify, I meant heavy lift as in EELV-Heavy class, not Saturn-V class. I agree that a lunar mission should be possible using existing, or soon-to-exist, launch vehicles rather than requiring development of a big new booster, but Delta II-class Falcon V is just too small to be useful in a 100-plus-ton-to-LEO type of mission. - Ed Kyle |
#17
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High-flight rate Medium vs. New Heavy lift launchers
I've only caught this thread at the last minute, so I really don't know if
this has been mentioned yet, it probably has, but why not use the Energia HLLV or an Americanized derivative, I got a site about it (www.k26.com/buran/) if ya want to read about it, Energia could easily lift 100t to LEO, sure it would take a bit of work to ramp it up again, but less than building any new launchers from scratch. How about something along the lines of what SeaLaunch did with the Zenits, only do it with Energia... "ed kyle" wrote in message om... (Rand Simberg) wrote in message . .. On 26 Jan 2004 09:00:22 -0800, in a place far, far away, (ed kyle) made the phosphor on my monitor glow in such a way as to indicate that: SpaceX hasn't proposed a heavy lift vehicle, which is required for this application. No, it's not. It's desired, by some, but it's not required. To clarify, I meant heavy lift as in EELV-Heavy class, not Saturn-V class. I agree that a lunar mission should be possible using existing, or soon-to-exist, launch vehicles rather than requiring development of a big new booster, but Delta II-class Falcon V is just too small to be useful in a 100-plus-ton-to-LEO type of mission. - Ed Kyle |
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High-flight rate Medium vs. New Heavy lift launchers
"Dholmes" wrote...
Going from just over a 5 meter diameter rocket to an almost six meter diameter rocket even if only for the central rocket would allow for a lot more launch capability in a Delta Heavy. Dual MB-60 second stage could also increase mass to orbit. If we do get sucked into the path of building heavier launchers, then perhaps the question is, how to do so in the most cost-effective manner. Is it easy to increase the diameter of the Delta IV or Atlas 5 to a 6 meter diameter (Atlas/Delta 6 anyone)? Or would it be more efficient to just strap on solids? It has also been said that the first stage is the cheapest, so perhaps the real debate should be on how much we incrementally launch to LEO each time. High-flight rate is important to the economics, and the assumption is that we want to make this step on a *permanent* basis this time, vs. the transitory nature of Apollo. Seems to me there is still an awful lot of unused capacity in the medium lift marketplace - and development costs for the EELVs that haven't been amortized. |
#19
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High-flight rate Medium vs. New Heavy lift launchers
Cris Fitch writes:
Is it easy to increase the diameter of the Delta IV or Atlas 5 to a 6 meter diameter (Atlas/Delta 6 anyone)? Or would it be more efficient to just strap on solids? Better still, strap on more cores. A modified central core with as many as six cores as strap ons. This would require some modification of the central core and to the launch facilities, but you could mostly take advantage of the existing production lines. Will McLean |
#20
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High-flight rate Medium vs. New Heavy lift launchers
"Krzys Kotwicki" writes:
I've only caught this thread at the last minute, so I really don't know if this has been mentioned yet, it probably has, but why not use the Energia HLLV or an Americanized derivative, The "NIH" factor: "Not Invented Here." -- Gordon D. Pusch perl -e '$_ = \n"; s/NO\.//; s/SPAM\.//; print;' |
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