new launch vehicle

[j05h]

>> So how about some 'out of the box' thinking on ways to achieve this?<br /> />Space Elevator<br /><br />Sea Dragon. Check out the painting of one next to USS Enterprise (the aircraft carrier). 500 tons to LEO, baby.<br /><br />http://astronautix.com/lvs/searagon.htm <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[cuddlyrocket]

I have to agree with no_way - what counts is the cost of the required rocket, not the performance. Who cares what the mass ratio is? What's the sticker price? (That's an exaggeration, but you get my point.)<br /><br />LOX is cheaper than water. The cost is in the bigger rocket, and the bigger engines to lift the mass of fuel. But big, simple engines might be cheaper than air-breathing ones.

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>the 'wings' are barely there. the configuration is a lifting body. check out the HyperX, the overall vehicle shape is the same as for an SSTO. <p><hr /></p></p></blockquote><br /><br />.. and you don't think "lifting body" is another form of "wing"??? It was designed out of necessity for conditioning air for aerodynamic propulsive thrust and lift. Otherwise, who is his/her right mind would want to design a fuselage structure that shape like a pancake?<br /><br />Ramjets and scramjets need vehicle forebody compression of inlet air in order to achieve the highest possible total-pressure recovery as possible, as these systems do not have turbopumps/ turbofan to provide additional pressure. Therefore these are relative low pressure (Pc) engines, in the order of less than 50 psia, whereas rocket engines put out as high as 3,000 psia. <div class="Discussion_UserSignature"> </div>

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>For example: <br /><br />A HTOHL TSTO airbreather (with expendable rocket powered upper stage and a staging velocity of Mach 16) that can operate from any 10,000 ft long runway, with a payload size of 17,500 lbs to LEO, and has a take-off weight of 385,000 lbs. <br />User cost to orbit, including amortization of investment and profit, is $1200/lb. <br /><br />A VTO rocket with the same payload will have a take-off weight in the 1.4 million pound plus range, will require a multi-million dollar custom launch pad, and will cost at least $2,500/lb to LEO. <br /><br />If you had a choice between these two and you were paying for the ticket out of your own pocket which would you choose? <p><hr /></p></p></blockquote><br /><br />Impressive numbers, but what are your assumptions ???<br /><br />This "HTOHL TSTO airbreather" does not exist. The technology behind the vehicle concept also are not mature enough to exist. All current programs are at a maturity level very far from a reusable system. <br /><br />You are comparing a launch system on paper with a very mature launch system. Apples and oranges.<br /> <div class="Discussion_UserSignature"> </div>

 

[spacefire]

cuddly, you know how on a multistage rocket whenever you add a little bit of weight-payload or structure- the amount of fuel increases greatly, which requires a bigger stage, or an extra stage, and so on?<br />now imagine the process in reverse, removing the weight of the oxidizer. the weight savings will be enormous, this requrie a smaller vehicle for the same payload, thus smaller overall weight and then a smaller engine and less fuel is required...and so on.<br />and remember the higher ISP and factor that into the equation as well. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[skywalker01]

<<How do you arrive at your cost figures ? >><br /><br />I assume you are asking about the TRCC vehicle?<br /><br />As regards that vehicle concept, specific details would make a large report.<br />In short, it was a bottoms up analysis that included amortization of the investment, cost to build, repair costs (both labor and parts) for each flight, manpower costs, facilities costs, upper stage cost, propellant costs, profit, and on and on . . . . <br />Basically it was a costing methodology that has been used to accurately estimate the cost of many programs for many years. In the places where some uncertainty existed the high side estimate was always used.<br />

 

[larper]

But, you have to collect the O2 and store it on board. You are not eliminating the onboard oxidizer, you are simply waiting to load it until you are at altitude. <br /><br />So, you have to have systems on board to collect, separate, and liquify. You have to loiter in the atmosphere to collect it, so you need MORE fuel, not less. And all of this is done at LOW velocities, so you need a system that deep throttle (yeah, my DC-X needs to deep throttle too). <br /><br />I don't seen such a complex system gaining anything, and expect it to loss a lot as far as cost savings, reliability, and maintenance is concerned. I even expect it to lose in performance as well.<br /><br />Launch vertically, get out of the atmosphere as fast as possible, then use your systems to gain orbital velocity. Simple, safe, reliable, and even reusable, perhaps, in the long run. And best of all, such a system scales up nicely. HTHL does NOT scale up easily. <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>

 

[larper]

In fact, if you are going to load anything at altitude, it might as well be the FUEL!!!!!!<br /><br />Simply take all of your oxidizer up with little fuel and meet up with a airborn tanker. Now, THIS type of system is understood, relatively safe and reliable, etc.<br /> <div class="Discussion_UserSignature"> <p><strong><font color="#ff0000">Vote </font><font color="#3366ff">Libertarian</font></strong></p> </div>

 

[strandedonearth]

"A HTOHL TSTO airbreather (with expendable rocket powered upper stage and a staging velocity of Mach 16) that can operate from any 10,000 ft long runway, with a payload size of 17,500 lbs to LEO, and has a take-off weight of 385,000 lbs. "<br /><br />385 klbs? My gut feeling says 'I don't think so.' I also doubt it'd get off the ground in 10,000 ft without some sort of ground accelerator or JATO rocket(s). Last but not least, what happens if an air-breathing engine fails just before or after liftoff? A great big fireball, that's what.<br /><br />Jet engine failure just before or after liftoff is what scares me most about HTO systems, although I used to like the idea. Not as big a concern with the White Knight or Pegasus systems, but when scaling up to a system that can orbit humans, trying to land fully loaded vehicle after an 'abort-to-runway' would require a ridiculously robust landing gear.

 

[spacefire]

the scramjet will use air from the atmosphee. for the injection phase,and possible for the early part of the flight, a rocket will be used, with oxydizer stored onboard. you will save a lot of weight because a large portion of the ascent and delta V gain is obtained using the scramjet. <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>

 

[propforce]

... so will the 5,000 to 10,000 deg. F air temperature be seen on every square inch of that airframe <img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> </div>

 

[skywalker01]

<< what counts is the cost of the required rocket, not the performance. Who cares what the mass ratio is? What's the sticker price? (That's an exaggeration, but you get my point.) >><br /><br />Your comments show a significant lack of understanding of the issues involved in costing an aerospace vehicle. In fact using such a gross exaggeration as you have would make it impossible for anyone using this thought process to ever arrive at a lower cost launch system as they would throw the baby out with the bath water every time early in the design process.<br /><br />Most people are aware that the cost of building similar types of vehicles is pretty much directly proportional to their empty weights. As a result the building costs for two competing systems can often times be compared by comparing their empty weight as long as similar design and fabrication methods are used in the vehicles being compared. <br />But this does not give an accurate comparison of actual launch costs as the operational costs can be quite different based on operational issues such as manhours/flight, degree of reusability, cost of custom facilities such as a launch pad, size of the initial investment, etc. Plus, it does not give an accurate comparison when there are significant differences in construction methods, materials, and operational procedures. For example, the cost/lb to build a 747 is quite a bit different then the cost/lb of an ocean going ship.<br /><br />So to compare the empty weight of a HTOHL TRCC powered LV (reusable) with expendable upper stage that takes off from existing runways and that can be serviced in existing aircraft hanagar facilities (and has a paylaod fraction of 4.5%) with the empty weight of a VTO rocket (expendable) that needs a custom hanagar and launch pad (and has a paylaod fraction of 1.5%) and whose development costs have been paid for by the government (and often times the facilities costs as well) does not give an accurate comparison of the user

 

[skywalker01]

<<You are comparing a launch system on paper with a very mature launch system. Apples and oranges.>><br /><br />How else would you perform a preliminary evaluation on a new concept to see if it was worth further development?<br /><br /><<This "HTOHL TSTO airbreather" does not exist. />><br /><br />That is true. But if that is a reason not to investigate it then how will any progress ever be made?<br /><br />What about the F-15 with ASAT? While sub-orbital it could be called a HTOHL TSTO.<br /><br />Same for Rutan's SpaceShipOne.<br /><br />And don't forget the B-52 with the X-15.<br /><br />And while it wasn't built, what about the SR-71 with the upper three stages of a Pegasus? (I guess that would be 4 Stages To Orbit wouldn't it.) All the pieces for that exist, all they have to do is mate them together.<br /><br />As to the assumptions, that would take more than I am willing to type. Also, there have been a number of detailed studies for these type of vehicles that have been published from around the world (USA, Germany, Japan, Russia). Some use a high Q flight profile, some use low Q. Some are SSTO, some are TSTO. Some take-off with all their propellants on-board, some use in-flight re-fueling for the LOX. Some are RBCC, some are TRCC, and some are variations of both of those. Gets some and read up.<br /><br />Question:<br /><br />Is there any idea out there that you think would make for a 'new (lower cost) launch vehicle'?

 

[skywalker01]

<<385 klbs? My gut feeling says 'I don't think so.'>><br /><br />That is the fun thing about doing a study for a vehicle like this, sometimes you discover things that surprise you.<br /><br />As for 'gut feelings' (mine included), I've been surprised so many times in studies like these (both good and bad) that I have gotten to the point that the only time I pay much attention to gut feelings is when I am at a restaurant.<br /><br />As to the why of the low take-off weight and low user cost?<br />Part of it is the small amount of LOX that it carries.<br />Part of it is that it is a dual fuel vehicle; hydrocarbon for the ramjet and LH2 for the rocket motors and scramjet (higher fuel density means reduced volume which means smaller lighter and cheaper).<br />Part of it is the staging velocity (higher staging velocity means smaller upper stage which means lower cost)<br />Part of it is the low Q flight profile (it avoids the thermal problems that NASP had)<br />Part of it is because the first stage is sub-orbital and never goes as fast as NASP.<br />Part of it was because it was designed for low cost from the very beginning instead of high performance. This lead to exploring parts of the design envelope that hadn't been explored before.<br />Part of it is that it can be serviced in existing aircraft hanagars and does not need a launch pad.<br />Part of it is because it can self-ferry.<br /><br />And yes it has engine out capability on launch. A 385,000 lb take-off weight isn't that big a deal in the aircraft world.<br /><br />The design was peer reviewed by a number of groups including MSFC and passed with flying colors.

 

[no_way]

<blockquote><font class="small">In reply to:</font><hr /><p>As regards that vehicle concept, specific details would make a large report<p><hr /></p></p></blockquote><br />In short, these numbers are just pulled out of the thin air for us. Funny that people calculate down to exact dollar how much a launcher is gonna cost with a technology that has never been flown, not telling what kind of organization is going to fly it from where, how often, what kind of payloads ( which affects insurance ) etc etc.<br /><br />In short, i call bs.<br />

 

[rlb2]

Here is my entry.<br /><br />The Heli-Rocket takes off on top a Delta IV or Titan IV rocket lands like a helicopter.<br /><br />Note: <br /><br />The image at left, the Heli-Rocket, is rendered on top of a Boeing Delta IV Rocket that is taking the place of the third stage.<br /><br /><br /><br /> <div class="Discussion_UserSignature"> Ron Bennett </div>

 

[skywalker01]

I have a copy of one of the data points that was printed out by the computer as part of all the trade studies that were performed for this vehicle study. When put up on the wall it covers about 36 ft^2. At the beginning of the study it took the computer 4 to 6 hours to crunch just one data point. It was a multi-year long study.<br /><br />If you have some broad brush stroke questions I'll answer those.<br />If you have some specific questions that don't take too much time I'll answer those.<br /><br />Otherwise I've got an extra 5 minutes so why don't you tell me all you know.<br /><br />In short, I say stick your bs back where you found it <img src="/images/icons/smile.gif" />

 

[gunsandrockets]

"A HTOHL TSTO airbreather (with expendable rocket powered upper stage and a staging velocity of Mach 16) that can operate from any 10,000 ft long runway, with a payload size of 17,500 lbs to LEO, and has a take-off weight of 385,000 lbs. <br />User cost to orbit, including amortization of investment and profit, is $1200/lb."<br /><br /> "A VTO rocket with the same payload will have a take-off weight in the 1.4 million pound plus range, will require a multi-million dollar custom launch pad, and will cost at least $2,500/lb to LEO."<br /><br />SpaceX is proving that wrong. The SpaceX uprated Falcon V booster with LH2/LOX second stage will send 20,000 pounds to LEO for a sale price of $20 million. That's only $1,000/lb to LEO.<br /><br />http://www.spacex.com<br /><br />

 

[gunsandrockets]

"I cant understand peoples fascination with airbreathing launch at all. The idea of using "free" oxidiser from atmosphere for boosting might sound technically neat, but get this: LOX in the tanks costs next to nothing."<br /><br />It's not about saving the cost of oxidizer, using an airbreathing 1st stage is about designing the stage to best match the conditions it flys in.<br /><br />The fact is rockets don't work very well at sea level altitude. Rockets only come into their own at altitudes above 25,000 feet. Plus it's so much easier to make an airbreathing 1st stage fully reusable than a pure rocket 1st stage. So there are plenty of good engineering reasons for air launch. <br />

 

[gofer]

It's technically interesting, but you can't consider costs separately from available demand markets. You do mention in fact dependence of the calculations on flight rates (amortization). At current flight rates when the best launchers on the market get 4 or 5 launches per year, and NASA at most expects to fly twice a year to the moon, an expendable vertically launched rocket with simple chemical propulsion and low labor and operating costs will trump a reusable air breathing concept any time. <br /><br />That's because the number one problem is not technical at all. There is nothing to do in space for an average man/investor! There are very few and very very expensive payloads to go around! Until that changes space planes and space elevators are going to gather dust on the shelves. Get folks spend trillions (like tourism and movies) on payloads and you'll get cheap access to space. I'd go as far as to say that the technical details would be then irrelevant. The space industry is still waiting for its Gates, Ford, Forbes, Hewlett-Packards, etc... And Musk is absolutely right betting on a simple rocket to get him off the planet.

 

[skywalker01]

<< SpaceX is proving that wrong. The SpaceX uprated Falcon V booster with LH2/LOX second stage will send 20,000 pounds to LEO for a sale price of $20 million. That's only $1,000/lb to LEO. >><br /><br />I hope they succeed.<br /><br />

 

[skywalker01]

<< You do mention in fact dependence of the calculations on flight rates (amortization). At current flight rates when the best launchers on the market get 4 or 5 launches per year, and NASA at most expects to fly twice a year to the moon, an expendable vertically launched rocket with simple chemical propulsion and low labor and operating costs will trump a reusable air breathing concept any time. >><br /><br />You are correct that flight rate has a big impact on user cost (and it is not all due to amortization costs). <br />It turns out that one of the major factors that allows for a major reduction in launch costs is to fly a smaller (cheaper to develop, purchase and operate) reusable vehicle with a smaller payload (smaller than the HLV payload) at a much higher flight rate. And since the payload is smaller that means that the existing launch market is enough to make use of that vehicle at the higher flight rate.<br />Add in the additional reduction in vehicle size that comes with air breathing and the improved average Isp and it gets even better.<br /><br />In any case, those are the trends that everyone who goes to the trouble of making an honest sizing and cost model find.<br />But please don't take my word for it. Learn how to put together a cost model if you don't already and make the comparison yourself. You will become significantly smarter as a rocket scientist if you do. Plus there are still plenty of vehicle configurations and propulsion concepts that have not been fully investigated in this manner such that the possibilty of discoverying an even lower user cost LV than the RBCC or TRCC vehicles is a very real possibility.<br />

 

[john_316]

<br />Not to break any bubbles here but the only active scramjet or ramjet rocket thats going to be in service any time soon is a new US Navy cruise missile and I dont see anything coming in the way of X-43 derived applications for some years to come.<br /><br /><img src="/images/icons/smile.gif" /><br /><br /><br />

 

[no_way]

The thing is, studies are just that, studies. Real-world experience, even with not exactly the same technologies means much more. There hasnt been any reuseable launch vehicle in service, ever. There have been some experimental reuseable rockets, which have given us a few small data points. The X-15, DC-X, Japanese RVT, various rockets by Armadillo Aerospace and of course SS1. None of them close to orbital, but i would say that data gotten from their operations costs is much more relevant to actual reuseable launch vehicles than any multi-year study. Of course, none of them was operational vehicle, the cost numbers we could get are for development phase which just gives an indication.<br /><br />Here are some questions about your airbreather, that i believe should be covered in very much detail in your study. Otherwise telling the exact cost numbers would be totally impossible.<br /><br />How big ground team would be in operations, launch preparations and tracking ? Total sum of salaries for operating team ?<br />From where would it be operating ? I assume somewhere in US, otherwise the legal stuff would be immensely more complicated.<br />What are the insurance costs ? Third-party liabilities ? Worst-case failure modes ?<br />How fast turnaround time and what ground equipment required for this ? Minimum launches a month to maintain given cost levels ?<br />Total cost of consumables ( i.e. propellants, possible heatshield refurbishments, pressurants etc) for each launch ? Servicing intervals and costs ? <br />

 

[cuddlyrocket]

Skywalker01, my point was that what counts in choosing the right launch vehicle is the cost, not its inherent performance. A big dumb throw-away might (I didn't say will) be cheaper for a given mission than a more sophisticated reusable craft.<br /><br />Now, this all depends on the relative costs of manufacture etc., and - for reusable vehicles - the flight rate, and - for throwaways - any reductions of their relatively 'mass' production.<br /><br />I don't know what the answer is, I'm not a rocket engineer. But the aim is 'lowest cost' (and safety, for manned vehicles).