"SpaceShipTwo could be single stage to SUBorbit"
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From: J. Clarke on 15 May 2010 06:20 On 5/15/2010 12:39 AM, Greg D. Moore (Strider) wrote: > J. Clarke wrote: >> On 5/14/2010 9:10 AM, Greg D. Moore (Strider) wrote: >>> J. Clarke wrote: >>>> On 5/13/2010 11:14 PM, Greg D. Moore (Strider) wrote: >>>>> J. Clarke wrote: >>>>>>> X-30 was way too much for NASA to do in one huge leap and would >>>>>>> have required billions more dollars just to try to make it work. >>>>>>> The state of the art in hypersonic propulsion still isn't where >>>>>>> it would need to be to build X-30 today (note that X-30 was >>>>>>> cancelled more than two decades ago). Hypersonic propulsion is >>>>>>> one of those promising looking technologies that's been "only a >>>>>>> few years away" for many decades. >>>>>> >>>>>> Uh, it's not there because Clinton pulled the plug on it. >>>>> >>>>> Really? Amazing. I didn't realize Clinton whas that powerful. You >>>>> mean no one else was capable of doing research on Hypersonic >>>>> propulsion? >>>> >>>> Nobody is capable of doing any kind of research on anything unless >>>> somebody is willing to put food on their table while they're doing >>>> it. >>>>> Hypersonic propulsion was " a few years away" before Clinton and is >>>>> still a few years away. >>>> >>>> So where would it be if development had been continued instead of >>>> being stopped and restarted again a decade or so later? >>> >>> Again, it wasn't stopped worldwide. Clinton wasn't that powerful. >>> >>> Other countries DID do research and development in the meantime. >> >> So who was putting the same kind of money into it that NASA had been? > > Ah, what's that sound? Oh right, the goalposts being moved. Yep, they were moved when Clinton chopped them down. >>> Or are you saying only R&D in the US is applicable? >> >> Who else has the economic resources of the US? I note you did not answer this.
From: J. Clarke on 15 May 2010 06:17 On 5/15/2010 12:37 AM, Greg D. Moore (Strider) wrote: > J. Clarke wrote: >> >> So how many Saturn Vs flew more than a few minutes and how many were >> reflown? I guess they don't work either. > > You're comparing apples to oranges. > > One is a an engine and the other is the vehicle. > > The F-1 engine (which would be equivalent to your scramjet) had HOURS of > actual firings before it was flown on a Saturn V. In addition, several were > re-used. Scramjets have neither of this. I see. So the only time that counts is flight hours for scramjets but test stand hours count for rockets. Can you say "double standard"? >>> But as you seem to know, perhaps you can point me to the ones that >>> have flown for hours. And the ones that have reflown. >> >> Straw man. > > Ummm, hardly. You're the one claiming that scramjets work. I'm asking you > to provide proof. If you are not familiar with the testing history perhaps you should not be pontificating about things you do not understand.
From: Greg D. Moore (Strider) on 15 May 2010 07:25 J. Clarke wrote: > On 5/15/2010 12:37 AM, Greg D. Moore (Strider) wrote: >> J. Clarke wrote: >>> >>> So how many Saturn Vs flew more than a few minutes and how many were >>> reflown? I guess they don't work either. >> >> You're comparing apples to oranges. >> >> One is a an engine and the other is the vehicle. >> >> The F-1 engine (which would be equivalent to your scramjet) had >> HOURS of actual firings before it was flown on a Saturn V. In >> addition, several were re-used. Scramjets have neither of this. > > I see. So the only time that counts is flight hours for scramjets but > test stand hours count for rockets. Can you say "double standard"? > No. Feel free to include test stand minutes for scramjets. Heck by Apollo 8, the F-1 had more FLIGHT time than Scramjets to date have. >>>> But as you seem to know, perhaps you can point me to the ones that >>>> have flown for hours. And the ones that have reflown. >>> >>> Straw man. >> >> Ummm, hardly. You're the one claiming that scramjets work. I'm >> asking you to provide proof. > > If you are not familiar with the testing history perhaps you should > not be pontificating about things you do not understand. In other words, you can't provide proof. Perhaps you should follow your own advice here. -- Greg Moore Ask me about lily, an RPI based CMC.
From: Sam Wormley on 15 May 2010 08:52 On 5/15/10 5:17 AM, J. Clarke wrote: > If you are not familiar with the testing history perhaps you should not > be pontificating about things you do not understand. "Scramjets have weight and complexity issues that must be considered. While very short suborbital scramjet test flights have been performed, no flown scramjet has ever been designed to survive a flight test. The viability of scramjet vehicles is hotly contested in aerospace and space vehicle circles, in part because many of the parameters which would eventually define the efficiency of such a vehicle remain uncertain. This has led to grandiose claims from both sides, which have been intensified by the large amount of funding involved in any hypersonic testing. Some notable aerospace commentators such as Henry Spencer and Jim Oberg have gone so far as calling orbital scramjets "the hardest way to reach orbit", or even "scamjets" due to the extreme technical challenges involved". Ref: http://en.wikipedia.org/wiki/Scramjet
From: M on 15 May 2010 10:51
On May 12, 8:49 am, Robert Clark <rgregorycl...(a)yahoo.com> wrote: > On May 12, 10:13 am, Marvin the Martian <mar...(a)ontomars.org> wrote: > > > ... > > > > The usefulness of just using a single stage for the suborbital flights > > > is to save on costs. Using two vehicles would cost twice as much to > > > develop and twice as much in per flight costs. > > > When people say things like that, it is a good argument that there is no > > intelligence on the usenet. > > > Multistage rockets to orbit are the used BECAUSE they are cheaper than a > > single stage to orbit, if you could even GET a single stage to orbit and > > back again. > > > It just kinda makes you wonder about people. > > This is for the *suborbital* XCOR flight which does cost half as much > per passenger as the two-stage Virgin Galactic system. > > Bob Clark Most people do not invest the time and brain power it takes to understand orbital mechanics. People today can barely handle basic math, because schools started allowing calculators in the 1980s and they did not learn basic math, much less calculus and algebra. |