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#21
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Fred J. McCall wrote:
Launching something they've already launched but that is made to LOOK like the new vehicle build confidence? If that were the case with the 1-X, you'd have a point. D. -- Touch-twice life. Eat. Drink. Laugh. http://derekl1963.livejournal.com/ -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL |
#22
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![]() I see it as a confidence exercise for an agency that hasn't fielded a new launch vehicle since 1981. Brian and shouldnt be doing it today. total waste of bucks and time |
#23
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![]() "Fred J. McCall" wrote in message ... Brian Thorn wrote: :One could also argue that the extreme height/width ratio of Ares I :needs to be proven a bit before trusting it with an upper stage and :Orion CSM. Lord knows, we've been hearing "it will be impossible to :control!" and "the wind will blow it into the tower" often enough for :the last four years. But until you've got real engines and real structure test flights won't tell you anything about controllability or potential resonant frequencies. True. I write engineering softare for a living and could tell you about dozens of cases where customers have changed seemingly small things in a design only to find out that the overall design doesn't work anymore. Of course, we sign NDA's for everything we do, so I can't openly talk about any specifics. In laymen's terms, just because Ares I-X may fly successfully doesn't mean that Ares I won't be problem free. The two designs just aren't similar enough to extrapolate much from Ares I-X and be confident that it will work for Ares I. Jeff -- "Take heart amid the deepening gloom that your dog is finally getting enough cheese" - Deteriorata - National Lampoon |
#24
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On Fri, 23 Oct 2009 10:07:36 -0700, Fred J. McCall
wrote: They do better to build a scale model and run time in a hypersonic wind tunnel. At least that way they'd get a decent first approximation of the flow fields around the vehicle. I honestly don't see what this 'test shot' will tell them that they can actually use. If one were to actually look, there has been a fairly extensive aerodynamic database development program, which includes both wind tunnel tests and CFD simulations over the flight trajectory. Correlating/correcting sunstantially subscale wind tunnel data to full scale flight data in itself is not necessarily a trivial exercise, nor an exact science. Does anyone remember the last new launch vehicle which NASA was even remotely associated with? Exactly how did the ATK ALV-X1 preform, and what were the findings of the ATK accident investigation? |
#25
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Jeff Findley wrote:
The RCS could be the design they're planning on using for Ares I, but I seriously doubt it. For this flight they only need roll control for first stage burn since the SRB TVC will handle the rest. I'm not sure if Ares I will need more than roll control on its RCS (for example, to keep the upper stage pointed in the right direction between first stage separation and successful start of the upper stage engine). Back when Ares 1 first got rolling, Scott Lowther was still working for ATK and noticed that their first paintings of the vehicle showed no means of roll control, so he pointed that out to them. Apparently they hadn't thought of that problem in regards to using the SRB, so added the roll control engines to the design on later paintings. That gives you some insight into the amount of thought that went into its design. Ares 1 is what happens when you let space cadets rather than engineers design a launch vehicle...it's always going to be so simple to do, and it ends up being a compete mess. SSTO? Hell, piece of cake. Pat |
#26
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Pat Flannery wrote:
Ares 1 is what happens when you let space cadets rather than engineers design a launch vehicle...it's always going to be so simple to do, and it ends up being a compete mess. SSTO? http://en.wikipedia.org/wiki/Single-stage-to-orbit "The early Atlas rocket is an expendable SSTO by some definitions. It is a "stage-and-a-half" rocket, jettisoning two of its three engines during ascent but retaining its fuel tanks and other structural elements. However, by modern standards the engines ran at low pressure and thus not particularly high specific impulse and were not especially lightweight; using engines operating with a higher specific impulse would have eliminated the need to drop engines in the first place." "The first stage of the Titan II had the mass ratio required for single-stage-to-orbit capability with a small payload. A rocket stage is not a complete launch vehicle, but this demonstrates that an expendable SSTO was probably achievable with 1962 technology." Hell, piece of cake. "Single-stage rockets were once thought to be beyond reach, but advances in materials technology and construction techniques have shown them to be possible. For example, calculations show that the Titan II first stage, launched on its own, would have a 25-to-1 ratio of fuel to vehicle hardware. It has a sufficiently efficient engine to achieve orbit, but without carrying much payload." "Ditto Saturn S-IVB and for all practical purposes, the SSME." Unless it is federally mandated, it ain't gonna happen. Americans are too ****ing stupid nowadays. Now you tell me, why is that? Pat |
#27
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Brian Thorn wrote:
Then so was the first Saturn I launch. The engines and tankage were all flight-proven, everything above Stage 1 was dummy, and the payload mockup didn't share Apollo's outer moldline. No one calls SA-1 a stunt. Of course, at that point Saturn I was seen as having uses other than just Apollo-related ones, including military ones like boosting Dynasoar into orbit. The strange problem Saturn I ran into is that the the rocket advanced so rapidly from design to first flight that they hadn't had time to develop any payloads for it by the time it was ready to go. Oh, for those days again. ;-) Pat |
#28
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Joseph Nebus wrote:
Though come to think of it, how long did the Little Joe and Big Joe rockets spend at the launchpad waiting to be gotten ready for their tests? Do you mean Redstone and Big Joe? Little Joe was a multi-solid-fueled rocket test vehicle for the Mercury abort and recovery systems: http://www.astronautix.com/lvs/litlejoe.htm Pat |
#29
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On Fri, 23 Oct 2009 18:48:36 -0700, Fred J. McCall
wrote: But it does require that you actually fly the real vehicle to do it. Which is NOT what they're doing here... What makes you think they haven't developed models all the way through a trajectory for 1-X itself? |
#30
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![]() If 1-X is your goal vehicle, that's all well and good. �If it's not, you're spending a lot of money for nothing useful. nasa is excellent and wasting money........... |
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Thread | Thread Starter | Forum | Replies | Last Post |
Ares IV?! | Pat Flannery | History | 10 | July 26th 09 09:30 PM |
Instead of Ares V... | Alan Erskine[_2_] | Policy | 16 | March 3rd 08 12:24 PM |
I've added FOUR updates to my Ares-1 article with some NEW calculations that (clearly) show WHY the new Ares-1 can't fly | gaetanomarano | Policy | 0 | November 12th 07 10:21 AM |
NewSpace rockets __ EELVs __ Ares-I __ REVISED Orion/Ares-I __ FAST-SLV __ chances of success | gaetanomarano | Policy | 9 | June 16th 07 12:03 AM |
in my opinion (both) Ares-I and Ares-V could NEVER fly once! ...could NASA rockets win vs. privates on launch date and prices? | gaetanomarano | Policy | 0 | May 10th 07 11:11 PM |