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#591
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On Fri, 25 Mar 2005 18:07:35 -0600, Reunite Gondwanaland wrote
(in article ): That's iron.rhino.F4, your friendly F-4 Phantom II Phanatic, who sent you the invitation because Reunite Gondwanaland doesn't have any invites yet. I've got 50 if anybody still wants one. Just un-munge my addy to email me and it's yours. -- Herb Schaltegger, GPG Key ID: BBF6FC1C "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." - Benjamin Franklin, 1759 http://www.angryherb.net |
#592
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On Fri, 25 Mar 2005 16:07:35 -0800, Reunite Gondwanaland
wrote: That's iron.rhino.F4, your friendly F-4 Phantom II Phanatic, who sent you the invitation because Reunite Gondwanaland doesn't have any invites yet. ....I do have one major beef with one of gmail's requirements. Where in the hell do they get off telling people they can't have an account name that's less than 6 characters? One of *my* requirements is that the account name has to either be "om" or at least aliasable to that. Google? I say g00bers... OM -- "No ******* ever won a war by dying for | http://www.io.com/~o_m his country. He won it by making the other | Sergeant-At-Arms poor dumb ******* die for his country." | Human O-Ring Society - General George S. Patton, Jr |
#593
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"Pat Flannery" wrote in message ... If you weren't expecting it, the physiological effect of suddenly seeing the sea ahead of you go up in flames would have been severe. "Run away!" "We're in a boat, dumbass!" "Oh...swim away! Swim away!" |
#594
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Derek Lyons wrote:
wrote: Derek Lyons wrote: A Shuttle can launch a wide variety of missions without requiring that there be something for it to meet in orbit. It carries it's purpose with itself. A CSM is quite limited in what it can do usefully on orbit without requiring a second launch. First, I don't see exactly what advantages this has (other than bundling launch failures together so that they affect multiple aspects of the mission rather than being more or less isolated). Lets see.. It utterly eliminates the need for rendezvous procedures, docking hardware, and independent flight capability for the payload. Except when it doesn't. Such as when rendezvous with the payload is unnecessary and the sole goal of the launch is to place the payload in orbit (e.g. when independent flight capability for the payload is already a requirement, which is quite a lot more often than never, e.g. HST, many ISS components, etc.). It eliminates the parasitic weight of a shroud for the payload. No, it just moves the weight of the shroud onto a different balance sheet. You may recognize it as the weight of the "cargo bay". It ensures that the payload and it's operators arrive on orbit, together, always. Except when it doesn't. And when it doesn't, it ensures that rather than just missing putting one payload in the proper orbit (or in orbit at all) you miss two or more. This could be an advantage, or at least a minimal disadvantage, if done right. The Shuttle is not an example of doing it right, however. And those are just the ones that occur off the top of my head. That's *not* to say the Shuttle is the is the best way to do things, or that it's advantages outweigh the disadvantages. But to pretend the Shuttle has no advantages is nothing but handwaving FUD. Certainly. As you say, the Shuttle as it exists currently has many fewer advantages than a hypothetical shuttle system of somewhat similar design. And that sort of practical concern is precisely what we need to keep in mind when devising practical, real world systems. And contrary to vigorous handwaving of the Capsule Cabal, the cargo will not tend to itself. Provisions must be made for it. Provisions must be made in either case. The question is whether the cost and capabilities of one method are clearly superior than the other, to date we do not have enough data in the form of actual, working systems to make that determination outside of theory. What data we do have is not supportive of the Shuttle's method. Second, this is a non-issue with regards to the subject of the sub-thread. If there is a payload that can be launched into LEO that can serve as a "target" for the Shuttle, in that it serves as a mission that is sufficiently useful to warrant launching the Shuttle with said payload in the cargo bay, then that same payload would obviously warrant a cargo-only launch for rendezvous (if necessary) in a cargo-bay-less manned spaceflight scenario. No, it's not obvious. You fail to account for all the things a 'target' payload needs that a 'piggyback' payload doesn't. It also ignore the problem that in few instances is a 'target' payload recoverable, whereas a 'piggyback' payload always is. This, at least, is a real advantage of a cargo vehicle system such as the Shuttle. However, you can get the same or similar advantages with systems that are significantly different from the Shuttle. I'll grant that this could be an issue with a hypothetical, low cost access to space system such as a high flight rate RLV or such like. In such cases it may be significantly, or even just incrementally, more expensive to launch separate payloads, and that might make just enough difference to not justify such a launch even though it might be justified with the other system. However, that sort of hypothetical scenario lives in a realm that is completely off the radar of the present discussion. Moreover, it is in a realm where the concerns brought up here are almost entirely moot. Here we are talking about big ticket items which justify the existence of the whole manned spaceflight program. And there it is beyond ridiculous to assume that there are such which are just small enough to justify Shuttle operations but not, say, a capsule based vehicle aimed at LEO operations. The history of the Shuttle is not one of cutting edge cost effectiveness. I think the existing examples throughout spaceflight history back up my interpretation fairly soundly on this point. So, it's a distinction without a difference. Hardly. You have accreted onto your original statement a series of statements regarding the advantages of the Shuttle, not all of which are related. With regard to your original statement that there is some sort of difference in the validity of the *justification* for a mission between a shuttle vehicle bringing its "target" with it and a vehicle rendezvousing with its target. I continue to maintain that there is none, regardless of the other advantages and disadvantages of either method. |
#595
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