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#21
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Shuttle dumped within 5 years
Dholmes wrote:
[snip] 2) "The key to the project, Smith said, is to keep the spacecraft simple and use technology that already has been developed. That also makes it cheap. " Lets hope they do that. If they do it will help a lot. Sadly, that's exactly what NASA has *not* been good at, even though it *is* exactly what we need. The only relevant launcher project they had that fit that description was the DC-X, and *that* was handed off to them from another government agency. The current NASA culture doesn't allow for doing things like that. That their idea of a DC-X follow-on was the X-33, tends to prove it. It was just the opposite. Too many new things at once, in one vehicle. Of course, advancing the state of the aerospace art is what they're for, but that doesn't necessairily mean very new technology, just a more useful repackaging of wat we've already learned.... |
#22
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Shuttle dumped within 5 years
"Doug Ellison" wrote in message ...
"Ultimate Buu" wrote in message ... The shuttle isnt the main cause of the problem here - it's management. The CAIB have demonstrated that. Use it properly, and carefully, and STS is saf.e A management failure, yes (management failed to stop shuttle flights after the STS-112 bipod ramp failure), but STS-107 was also an engineering failure. Engineers failed to understand how serious the problem could be and failed to communicate to management how limited their understanding and modeling of the problem was. Unlike 51-L, no engineers stood up this time. - Ed Kyle |
#23
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Shuttle dumped within 5 years
"Dholmes" wrote in message ... "Kim Keller" wrote in message m... "Alex Terrell" wrote in message om... Down mass isn't really needed, except for Hubble return. Sure it is. There are plans to change out experiment racks, and those can only be changed out through the use of an MPLM. Up mass: A Delta 4 Heavy has similar up mass, at a much lower (though still too high) cost. And there's nothing to put on top of it, nor budget to build something. If NASA uses a little common sense they should be able to adopt the technology from the OSP to an expendable ATV which could be launched aboard the heavies. ESA's doing this one for you surely? Doug |
#24
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Shuttle dumped within 5 years
"Kim Keller" wrote in message om...
"Alex Terrell" wrote in message om... Down mass isn't really needed, except for Hubble return. Sure it is. There are plans to change out experiment racks, and those can only be changed out through the use of an MPLM. Any idea of the requirement? I bet it's not 15 tons requiring a crew of 7 to babysit it home. Up mass: A Delta 4 Heavy has similar up mass, at a much lower (though still too high) cost. And there's nothing to put on top of it, nor budget to build something. A shroud to house 20 ton modules? That won't be too expensive. -Kim- *my opinions, not my employers'* |
#25
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Shuttle dumped within 5 years
"Dholmes" wrote in message ... Remember one of the things that keeps shuttle costs up is low use the new OSP is pretty much guaranteed 12-20 flights a year, with 6-7 just for crew and the rest unmanned for cargo. The traffic models I've seen are nearly so vigorous. -Kim- |
#26
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Shuttle dumped within 5 years
"Brian Thorn" wrote in message ... On Mon, 01 Sep 2003 22:13:45 GMT, "Dholmes" wrote: NASA is bound to get some funds to replace the Shuttle. That's not a given. It very well might, but at $12 billion for OSP, Congress might put off replacing the Shuttle again and just offer a couple of billion for Shuttle upgrades. Remember one of the things that keeps shuttle costs up is low use the new OSP is pretty much guaranteed 12-20 flights a year, with 6-7 just for crew and the rest unmanned for cargo. a. That assumes ISS grows to 6 or 7 crew, which is far from certain. No, I just assumed slightly less then the numbers that have been going up on the shuttle. In 2001 my quick count was 31 people went to the station by shuttle. 7*4=28 b. 20 flights a year is way out there. That's 13 flights a year for cargo. At the very least, the US ATV will have cargo comparable to Europe's ATV... about 15,000 lbs. That's versus 20,000 lbs for Shuttle/MPLM, which is manifested for four flights per year. So we're looking at 6 US ATV flights per year to replace Shuttle delivered cargo. Add a 7th for good measure, to handle things like water that Shuttle delivers for free. And if ISS does not grow past Core Complete's three crew... a distinct possibility if Congress ponies up big bucks for OSP or Shuttle Upgrades... you'll need fewer resupply flights. I was adding in the ATV. I was making the hopeful assumption that they would base the ATV on the same technology to cut costs. Ideally they would take the old parts from the OSPs to use on the ATVs. Fly the OSP manned for a few years, then unmanned for a few years, then finally stripped as an ATV. If they base it on the same technology as the OSP it will probably be a little smaller then the European one around 8-10 thousand pounds. IMO you are not doing the same for shuttle flights as you are doing for OSP and the shuttle has a high base cost. If all you need are 6 people and a few tons of cargo then you only need 1 shuttle flight a year and the cost per flight goes through the roof. Even at 12 people a year then you have around 8-10 flights vs 2 for the shuttle. |
#27
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Shuttle dumped within 5 years
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#28
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Shuttle dumped within 5 years
On Tue, 02 Sep 2003 12:35:06 GMT, in a place far, far away,
(Christopher) made the phosphor on my monitor glow in such a way as to indicate that: And when the fleet is reduced to two shuttles, what then? Keep flying until it's reduced to zero, or decide that maybe the nation has been taking a flawed approach to manned spaceflight (which the OSP simply perpetuates). So we should abandon space, and never go back when the final shuttle has landed a final time? No, we should develop a true space transportation industry (which doesn't mean letting NASA develop yet another single launch system). -- simberg.interglobal.org * 310 372-7963 (CA) 307 739-1296 (Jackson Hole) interglobal space lines * 307 733-1715 (Fax) http://www.interglobal.org "Extraordinary launch vehicles require extraordinary markets..." Swap the first . and @ and throw out the ".trash" to email me. Here's my email address for autospammers: |
#29
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Shuttle dumped within 5 years
Brian Thorn wrote in message . ..
b. 20 flights a year is way out there. That's 13 flights a year for cargo. At the very least, the US ATV will have cargo comparable to Europe's ATV... about 15,000 lbs. That's versus 20,000 lbs for Shuttle/MPLM, which is manifested for four flights per year. The 8,605 kg Shuttle/MPLM "payload" mass includes the MPLM racks. The 7,250 kg ATM payload mass does not include that vehicle's 3,900 kg cargo carrier mass, so the delivered masses aren't as far apart as they might initially seem. At any rate, a US cargo carrier would have advantages over ATV that would allow more payload - it would be launched from a higher latitude by a more powerful launch vehicle. The reason ATV weighs 20.5 metric tons at launch but only carries 7.3 tons of cargo is that Ariane 5V can't get 20.5 tons into a 51.6 degree orbit. Instead, ATV must use its own propellant (it has to carry 4.5 tons of it) to finish the job after Ariane boosts it into an unsustainable 30 x 300 km x 51.6 degree orbit. Delta IV-H, on the other hand, can put 24,000 kg directly into a circular 500 km x 51.6 degree orbit. It should be possible to get 10,000 kg payload to ISS with this rocket, assuming a slight improvement on existing Progress mass fractions (Progress M1, a design derived from the initial 1960s Soyuz design, weighs 7,250 kg at liftoff and has carried up to 2,677 kg payload). It might be possible to serve ISS with only three annual big cargo launches augmented by cargo brought up on two or three annual CTV missions. Proton, launched from an even higher latitude, could nearly do the same thing. - Ed Kyle |
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