#21
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Dave,
I think VG is getting very, very close. I haven't been following their progress but perhaps by end of this year or next this statement may no longer be true? suborbital flights have been real 4 decades, there don't live the least sense to invent wheels. vg Just has wasted Time & Nothing more. their scheme is about to be ridiculously unreliable + costly: feathers have big chance to fail! Musk claims to have booked considerable amount of business for Falcon 9 already with or w/o NASA COTS. Time will tell, not much time mind you. musk has no any idea WTF & WTH Space Industry is XD You need to provide evidence of this. I don't see any. Musk's plan is to make Dragon re-usable at the outset. And the next gen of Dragon is to land on land to speed refurbishment. put your eyes onto Tsiolkovsky equation, it'd be helpful. |
#22
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“If you look at the cost of a Falcon 9 rocket – which is a big, one million pounds of thrust rocket, yet the lowest cost rocket in the world, it’s still 50-60 million dollars. But if you look at the cost of the fuel and oxygen and so forth, it’s only about 200,000 dollars. So obviously if we can reuse the rocket, say one thousand times, then that would make the capital cost of the rocket per launch only about 50,000 dollars.
-------------------- http://www.nasaspaceflight.com/2012/...ogy-this-year/ XDDDDDDDDD Just baby talks of him: no the least idea exists there of service works, infrastructure -- Never mind only say Cheese XDDDDD |
#23
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Public letter:
On Jan 16, 1:24*pm, Glen Overby wrote:
Mike DiCenso wrote: What would be done if NASA had excepted Rockwell's offer would have been to take the older orbiters out of service for several for a very extensive rebuild at Palmdale after the Block II orbiters came into service. Sadly there probably would not have been any money for such an effort. Why rebuild all of them? *They only ever had four flying orbiters at a time so they could have flow three Block II orbiters and one older one, using the remaining Block I orbiters as spares for it. Which was a huge mistake in hindsight. The STS program always ran into problems as result of a low fleet number, especially when in came to rotating orbiters for maintaince and upgrades in the OMDP. With 7 operational orbiters, you get more flexibility in launch rates, especially if something happens to one of the orbiters. If Vandenburg had been made operational for Shuttle, it would have allowed 2 vehicles to be based out of there instead of one and four at KSC, with one orbiter rotating between them at a time or down for maintaince and upgrades with little impact to flight rates and schedule. But at the very least, a major rebuild of the three newer vehicles of the "Block I" type (Discovery, Atlantis, and Endeavour), would be in order. -Mike |
#24
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Public letter:
On Jan 18, 3:53*am, Mike DiCenso wrote:
On Jan 16, 1:24*pm, Glen Overby wrote: Mike DiCenso wrote: What would be done if NASA had excepted Rockwell's offer would have been to take the older orbiters out of service for several for a very extensive rebuild at Palmdale after the Block II orbiters came into service. Sadly there probably would not have been any money for such an effort. Why rebuild all of them? *They only ever had four flying orbiters at a time so they could have flow three Block II orbiters and one older one, using the remaining Block I orbiters as spares for it. Which was a huge mistake in hindsight. The STS program always ran into problems as result of a low fleet number, especially when in came to rotating orbiters for maintaince and upgrades in the OMDP. With 7 operational orbiters, you get more flexibility in launch rates, especially if something happens to one of the orbiters. If Vandenburg had been made operational for Shuttle, it would have allowed 2 vehicles to be based out of there instead of one and four at KSC, with one orbiter rotating between them at a time or down for maintaince and upgrades with little impact to flight rates and schedule. But at the very least, a major rebuild of the three newer vehicles of the "Block I" type (Discovery, Atlantis, and Endeavour), would be in order. -Mike was the issue lack of orbiters or lack of payloads? |
#25
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Public letter:
Fred J. McCall wrote:
David Spain wrote: Fred J. McCall wrote: The problem with this approach on reusable vehicles is that you wind up with a fleet of 'one offs', each of which has its own special reprocessing requirements and logistics tail. That's a very expensive way to operate. But you do still have the re-usability that you lose with expendables. But I agree with your point that the operational cost is a question of ground infrastructure. My point was that this is the goal of the cost reduction, if I can retire the costly to operate vehicles quickly maybe I can get the ground infrastructure cost down as well. And I'd only be servicing a smaller number of vehicles (say two, with a CRV on standby with an expendable) rather than an entire fleet of four or five, however with a new vehicle coming on line every 5 years or so. I think having only say two operational orbiters at any given time + CRV as a backup (given the sustainable flight rates NASA was able to achieve) would have been just fine. But your point is well taken. With the one size fits all Shuttle approach that was taken, and the lower flight rates post-Challenger, this still might have been too costly to do. But to retire reusable relatively quickly and have it make economic sense, at least one of two things must be true: 1) The capital cost of reusability must be low. This one is typically not true, although it is more likely to be true if 2), below, is true. 2) The vehicles only have limited reusability (reusable for a small number of flights and then are expended). If you're 'retiring' vehicles that still have lots of flight life left in them, your 'incremental' improvements on the next block would need to lead to huge decreases in flight expense for the replacement to make sense (as you're losing the sunk cost in the old hardware when it could continue to generate revenue). Of course you're right. It wouldn't make sense to 'retire' vehicles unless the first few were actually just trial prototypes. That didn't happen with Shuttle, well with the one exception of Enterprise which did get 'retired'. As Mike DiCenso points out if you're recycling orbiters, a larger number is somewhat preferable to a smaller number. But we weren't really recycling as much as building one-offs. The military/commercial options didn't pan out and the four that NASA ended up with was more than sufficient for their needs. The Challenger accident was truly unfortunate, because it closed the door on the possibility that an operation like USA could have been spun off to do the commercial payloads, perhaps even renting NASA facilities but under the USA moniker, to help keep NASA's expenses down. That would have done zero to make a USA-like operation profitable however. But it would have at least put someone on the right path to find out. Shuttle did not teach us much here. [snip] It's uncertain how much the price has to drop before a significant market expansion would take place. Agreed. It's hard to know what costs are acceptable and what could drive a market expansion if you don't know your realized and projected revenue streams. For COTS, right now the only serious market is comsat ops*. That may not be a big enough market to allow COTS to operate profitably. Then we're back to SLS type approaches and you can forget about 'price drops'. Dave * - Lurkers, please spare me the SPS pitch. Come back and post here after you've got a case history whereby a company using public/private venture capital has a working prototype in orbit and has customers lined up for the next big one. Otherwise I'm not interested in your L5 religion, keep lurking. |
#26
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Public letter:
SarK0Y wrote:
*Dave*, I think VG is getting very, very close. I haven't been following their progress but perhaps by end of this year or next this statement may no longer be true? suborbital flights have been real 4 decades, there don't live the least sense to invent wheels. Not with paying customers they haven't. vg Just has wasted Time & Nothing more. their scheme is about to be ridiculously unreliable + costly: feathers have big chance to fail! YOU'RE WRONG! (or are you dropping those feathers in a vacuum?) :-D Musk claims to have booked considerable amount of business for Falcon 9 already with or w/o NASA COTS. Time will tell, not much time mind you. musk has no any idea WTF & WTH Space Industry is XD WTF? ;-) You need to provide evidence of this. I don't see any. Musk's plan is to make Dragon re-usable at the outset. And the next gen of Dragon is to land on land to speed refurbishment. put your eyes onto Tsiolkovsky equation, it'd be helpful. It predicts that sub-orbital flight with conventional fuels is theoretically impossible? Dave |
#27
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Public letter:
David Spain wrote:
SarK0Y wrote: vg Just has wasted Time & Nothing more. their scheme is about to be ridiculously unreliable + costly: feathers have big chance to fail! YOU'RE WRONG! (or are you dropping those feathers in a vacuum?) :-D OK on a more serious note. There are a lot of components on an aircraft that failure on approach can lead to disaster as well. I lump the 'feathering' approach on SpaceShip I - II in that category. With only a few powered flights of SS-I and no powered ones on SS-II yet: http://www.spaceshiptwo.net/press.html but 7 solos according to the above, we can't really pass judgment on its operational reliability. It's not in operation yet. We can say it has been successfully recovered 7 times in 7 non-powered flight tests including at least one 'feathered' test drop. Again if this scheme was so awful why didn't the Canadian Arrow win the X-Prize? If it was too costly, why did Canadian Arrow bow out of the space tourism business? Even something as simple as a parachute can get tangled. There are always risks. The VG waiver of liability you'll have to sign to take the flight will spell it all out for you I'm sure. Dave |
#28
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Dave, decades by decades conventional scheme has confirmed its safety & cheapness 4 orbital flights. what the least reason can exist on this planet 4 ye, to've had any hesitation of that way 4 suborbital flights???!!! + capsule can be really reusable because heat & pressure load are far not so severe like reentry from orbit + capsule can be equipped with booster to decelerate reentry.
in short, bad strategies have been only cause to make suborbital tourism so deeply sad & useless. |
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