A kerosene-fueled X-33 as a single stage to orbit vehicle.
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From: Androcles on 4 May 2010 15:40 "Robert Clark" <rgregoryclark(a)yahoo.com> wrote in message news:93e0cc63-95db-4d5f-875c-de875ed858fe(a)d39g2000yqa.googlegroups.com... On May 4, 2:58 pm, "Androcles" <Headmas...(a)Hogwarts.physics_z> wrote: > > ============================================= > I've just explained what I'm arguing, do you want me to paste it again? > Ok, I'll paste it again. > > Airliners burn two tons of fuel on take-off and throttle back to > cruise. They have the advantage of using atmospheric oxygen > up to 50,000 feet (10 miles) and normally cruise economically > at 30,000 feet where the air is thin enough to reduce drag and > thick enough to breathe (they are pressurised to 8000 feet, > compressors force air into the cabin). If you've ever flown > you'll know your ears pop. > But to reach the ISS an altitude of 200 miles is needed, so an > oxidant needs to be lifted along with the fuel for the other 190 > miles. > http://en.wikipedia.org/wiki/Space_Shuttle_external_tank > "A Space Shuttle External Tank (ET) is the component of the Space Shuttle > launch vehicle that contains the liquid hydrogen fuel and liquid oxygen > oxidizer." > > Nowhere in your analysis above have you considered that. > > The laws of physics and chemistry cannot be defeated, it is only economics > that you can meddle with, joules per dollar. I have to tell you honestly > that you'll never convince an aeronautical engineer of your quick fix, > you've left out far too much reality. What is the point of your argument? ==================================== Let's see, there are a few. 0) NASA, the Russian Federal Space Agency, the China National Space Administration and the European Space Agency I shall refer to as the agencies. 1) The agencies have already heard of kerosene and opted for hydrogen instead. 2) The agencies know they can combine oxygen and hydrogen to produce H2O. 3) The agencies know other exhaust gasses will be toxic, in particular carbon monoxide. 4) The agencies know they will have to lift heavy liquid oxygen (atomic mass 16), a point Clark ignores. 5) Clark thinks combining a mixture of carbon chains that typically contain between 6 and 16 carbon atoms (atomic mass 12) per molecule, aka kerosene, with oxygen, will yield more thrust than pure water because Clark has a Ph.D. in chemistry and the agencies are all idiots. Now, do tell... what is the point of YOUR argument?
From: Robert Clark on 6 May 2010 00:27 On Apr 25, 2:39 am, Robert Clark <rgregorycl...(a)yahoo.com> wrote: > ... the SSTO can actually help if you wanted to get a TSTO to > loft larger payloads. For instance I argued that the X-33, when kerosene > fueled, could become orbital, though with small payloads, and the full-sized > VentureStar could loft large payloads when kerosene fueled. However, the > full-sized VentureStar would be quite expensive, in the billions of dollars > range, while the X-33 would be about $360 million to build a new one. > So the smaller X-33 could launch smaller payloads at an smaller initial > investment. > But quite key also is that using two of them as the first and > second stages, they could now serve as a heavy launch system, and this > would be at a much smaller investment than building the full-size VentureStar. > Note also the comparison to a two-stage expendable system: the two > stages in such a case would be expendable because they don't have sufficient > mass ratio to singly get to orbit. That is they aren't weight optimized. But > suppose you were able to make each stage be so optimized that each > separately could reach orbit at the same size vehicles. Then now note this > means these weight optimized versions could therefore loft *more* payload > because the weight savings could go to extra payload AND would be less > costly per launch in being reusable. This is a general feature of using SSTO vehicles to serve as your stages for multistaged rockets. It shows there really is no valid objection to developing SSTO's. For even if true that you could lift more payload by using multistage rockets you could lift *even* more if you made those stages be separately SSTO's. This works even if the SSTO's are expendable, not reusable. You may not want to develop a reusable version because of the cost, but just using an expendable vehicle so weight optimized that it is separately SSTO capable means you can loft more payload on that expendable rocket. Here's an example of this for the Falcon 1 first stage SSTO discussed here: Newsgroups: sci.space.policy, sci.astro, sci.physics, sci.space.history From: Robert Clark <rgregorycl...(a)yahoo.com> Date: Sun, 14 Mar 2010 18:24:37 -0700 (PDT) Subject: Re: A kerosene-fueled X-33 as a single stage to orbit vehicle. http://groups.google.com/group/sci.space.policy/msg/b2dfd3ce833c4470?hl=en I'll use the single engine version discussed there to make a better comparison to the actual Falcon 1 two-stage rocket. For the single engine SSTO version I used 25% less propellant to be able to be lofted by a single RD-0124 engine. Using just one of the RD-0124's brings the dry mass down to 1,271 kg. But the tank weight is reduced too. Using the common 100 to 1 estimate of propellant mass to tank mass ratio for kero/LOX, I'll reduce the tank weight 71 kg to bring the dry mass to 1,200 kg. The propellant mass being reduced 25% is now 20,325 kg. So using an average Isp of 345 s for the RD-0124 we would be able to loft about 580 kg to orbit since 345*9.8ln(1 + 20325/(1,200 + 580)) = 8,517 m/s. This is still more than the current two-stage version of the Falcon 1, and would be cheaper in being single staged and using only one engine, and by using a cheaper Russian engine as well. Now suppose we used two of these Falcon 1 derived SSTO's mated bimese fashion to loft higher payloads. I estimate we could loft a 2,600 kg payload: the first stage portion of the trip would have a delta-V of 345*9.8ln(1 + 20,325/(2*1,200 + 20,325 + 2,600)) = 1,992 m/s. The second stage portion would have a delta-V of 360*9.8ln(1 + 20,325/ (1,200 + 2,600)) = 6,521 m/s, for a total delta-v of 8,513 m/s. Note a 2,600 kg payload is more than 5 times the payload of the current Falcon 1 two-stage rocket. So by weight optimizing our stages and using high performance engines, to the extent the stages are separately SSTO capable, we can increase our payload multiple times. Bob Clark
From: Robert Clark on 6 May 2010 07:07 On May 4, 3:40 pm, "Androcles" <Headmas...(a)Hogwarts.physics_z> wrote: > "Robert Clark" <rgregorycl...(a)yahoo.com> wrote in message > ... > > What is the point of your argument? > ==================================== > Let's see, there are a few. > 0) NASA, the Russian Federal Space Agency, the China National Space > Administration and the European Space Agency I shall refer to as the > agencies. > 1) The agencies have already heard of kerosene and opted for hydrogen > instead. > 2) The agencies know they can combine oxygen and hydrogen to produce H2O. > 3) The agencies know other exhaust gasses will be toxic, in particular > carbon monoxide. > 4) The agencies know they will have to lift heavy liquid oxygen (atomic mass > 16), a point Clark ignores. > 5) Clark thinks combining a mixture of carbon chains that typically contain > between 6 and 16 carbon atoms (atomic mass 12) per molecule, aka kerosene, > with oxygen, will yield more thrust than pure water because Clark has a > Ph.D. in chemistry and the agencies are all idiots. > > Now, do tell... what is the point of YOUR argument? I suggested a possible reason why this hasn't been done before here: Newsgroups: sci.space.policy, sci.astro, sci.physics, rec.aviation.military, sci.military.naval From: Robert Clark <rgregorycl...(a)yahoo.com> Date: Sun, 25 Apr 2010 08:35:56 -0700 (PDT) Subject: Re: A kerosene-fueled X-33 as a single stage to orbit vehicle. http://groups.google.com/group/sci.space.policy/msg/df9d96d2f12a75c3?hl=en The idea had been it has to be done by hydrogen because it is the "best" fuel, since it has the highest Isp. Ironically, it turns out that, at least among the liquid fuels, it is the worst one to use. Another reason why it wasn't done is that the argument was made "why make an SSTO when using multistage rockets you can lift greater payload?" Then the argument was that even if technically doable it wasn't economical to do so. However, as I argued in these two posts by using SSTO's as the stages you can increase your payload multiple times. So in fact it is *multiple times* more economical to do so: Newsgroups: sci.space.policy, sci.astro, sci.physics, rec.aviation.military, sci.military.naval From: Robert Clark <rgregorycl...(a)yahoo.com> Date: Sat, 24 Apr 2010 23:39:37 -0700 (PDT) Subject: Re: A kerosene-fueled X-33 as a single stage to orbit vehicle. http://groups.google.com/group/sci.space.policy/msg/f2cbdd51935445b5?hl=en Newsgroups: sci.space.policy, sci.astro, sci.physics, rec.aviation.military, sci.military.naval From: Robert Clark <rgregorycl...(a)yahoo.com> Date: Wed, 5 May 2010 21:27:03 -0700 (PDT) Subject: Re: A kerosene-fueled X-33 as a single stage to orbit vehicle http://groups.google.com/group/sci.space.policy/msg/17d7c8088c875307?hl=en And in the following I explained why it wasn't being done by the Russians who have the high performance hydrocarbon engines needed: Newsgroups: sci.space.policy, sci.astro, sci.physics, sci.space.history From: Robert Clark <rgregorycl...(a)yahoo.com> Date: Wed, 28 Apr 2010 19:56:32 -0700 (PDT) Subject: Re: A kerosene-fueled X-33 as a single stage to orbit vehicle. http://groups.google.com/group/sci.space.policy/msg/04dd2e7a9a7151b5?hl=en You need *both* the high performance engines AND the lightweight structures. The U.S. or the Russians had one but not the other. It's the combination that makes SSTO possible. Bob Clark
From: Androcles on 6 May 2010 07:29 "Robert Clark" <rgregoryclark(a)yahoo.com> wrote in message news:486970b5-ba74-434f-bcf9-0faf305a01f3(a)o8g2000yqo.googlegroups.com... On May 4, 3:40 pm, "Androcles" <Headmas...(a)Hogwarts.physics_z> wrote: > "Robert Clark" <rgregorycl...(a)yahoo.com> wrote in message > ... > > What is the point of your argument? > ==================================== > Let's see, there are a few. > 0) NASA, the Russian Federal Space Agency, the China National Space > Administration and the European Space Agency I shall refer to as the > agencies. > 1) The agencies have already heard of kerosene and opted for hydrogen > instead. > 2) The agencies know they can combine oxygen and hydrogen to produce H2O. > 3) The agencies know other exhaust gasses will be toxic, in particular > carbon monoxide. > 4) The agencies know they will have to lift heavy liquid oxygen (atomic > mass > 16), a point Clark ignores. > 5) Clark thinks combining a mixture of carbon chains that typically > contain > between 6 and 16 carbon atoms (atomic mass 12) per molecule, aka kerosene, > with oxygen, will yield more thrust than pure water because Clark has a > Ph.D. in chemistry and the agencies are all idiots. > > Now, do tell... what is the point of YOUR argument? I suggested a possible reason ============================================== You've not understood the question. I didn't ask for a reason, I asked what the POINT of your ARGUMENT is (its purpose). You can pontificate until you are blue in the face, but if you want to argue then you'll answer the points I've made or I shall simply ignore yours as you are ignoring mine, and that makes your argument futile.
From: Robert Clark on 6 May 2010 10:13
On May 6, 7:29 am, "Androcles" <Headmas...(a)Hogwarts.physics_z> wrote: > "Robert Clark" <rgregorycl...(a)yahoo.com> wrote in message > > news:486970b5-ba74-434f-bcf9-0faf305a01f3(a)o8g2000yqo.googlegroups.com... > On May 4, 3:40 pm, "Androcles" <Headmas...(a)Hogwarts.physics_z> wrote: > > > > > "Robert Clark" <rgregorycl...(a)yahoo.com> wrote in message > > ... > > > What is the point of your argument? > > ==================================== > > Let's see, there are a few. > > 0) NASA, the Russian Federal Space Agency, the China National Space > > Administration and the European Space Agency I shall refer to as the > > agencies. > > 1) The agencies have already heard of kerosene and opted for hydrogen > > instead. > > 2) The agencies know they can combine oxygen and hydrogen to produce H2O. > > 3) The agencies know other exhaust gasses will be toxic, in particular > > carbon monoxide. > > 4) The agencies know they will have to lift heavy liquid oxygen (atomic > > mass > > 16), a point Clark ignores. > > 5) Clark thinks combining a mixture of carbon chains that typically > > contain > > between 6 and 16 carbon atoms (atomic mass 12) per molecule, aka kerosene, > > with oxygen, will yield more thrust than pure water because Clark has a > > Ph.D. in chemistry and the agencies are all idiots. > > > Now, do tell... what is the point of YOUR argument? > > I suggested a possible reason > ============================================== > You've not understood the question. I didn't ask for a reason, I asked > what the POINT of your ARGUMENT is (its purpose). > You can pontificate until you are blue in the face, but if you want to > argue then you'll answer the points I've made or I shall simply ignore > yours as you are ignoring mine, and that makes your argument futile. I'm arguing two points: one that SSTO is technically feasible, and two that it is financially beneficial. In the case of two X-33's mated in bimese fashion, you could have a fully reusable, heavy lift launcher that would lower the costs to orbit by two orders of magnitude. Again I want to emphasize it doesn't have to be the Lockheed X-33. I just used this because it was already largely built. The other proposed suborbital demonstrators by Rockwell and McDonnell-Douglas had similar capabilities as the Lockheed X-33. They would likewise become fully orbital when switched to kerosene-fueled. And they would likewise cut the costs to orbit by two orders of magnitude when used in staged fashion. Bob Clark |