Clean Sheet Big Dumb Booster?

[mlorrey]

First off, I wouldn't put an ET into a polar orbit, as I said. I'd send all payloads to the station, dock the ETs there, and have the OTVs move the payloads to their destination orbits. The amount of extra fuel a booster requires at its low Isp to put a payload into polar orbit is many times more than what is required for an electric propelled OTV to move it from a 28.5 deg orbit to a polar orbit. Thus, the ET launcher would bring up the extra fuel in its tanks, as residuals, and these would be recovered and used by the OTV to tranfer the payloads orbit.<br /><br />As a matter of fact, I know how much delta-v that requires (as can anybody who knows how to google). A normal inclination change is one where you keep the original altitude, eccentricity, etc. However, we are not dealing with normal payloads here, we are dealing with military spy satellites, which are the primary occupants of polar orbits. Such satellites orbit in higher orbits than other LEO satellites, typically 400-800 miles altitude, in order to make it more difficult to send manned inspection missions or launch ASAT weapons from ground or air launched platforms at them.<br /><br />If, for instance, our space station is located at 250 mile orbit in a 28.5 degree inclination, it would need to make about a 60 degree inclination change to reach a polar orbit. If you were to try to make the trip without changing altitude at all, you'd burn up a lot of fuel on wasted maneuvers. This is a case where the long way around is actually the shortest. It turns out that the higher orbit you are in, the less delta-v it takes to change inclinations, primarily because orbital velocity is lower at higher orbits. So, the shortest (i.e. lowest delta-v) way to change to a polar orbit would be to move the payload out beyond 10,000 miles, change inclination there, then come back down to the lower orbit, deliver the payload, then return the same way.<br /><br />Given this, the cheapest way to go about it would be first change the

 

[mlorrey]

"It would be really great if you would loose your obnoxious attitude. "<br /><br />You give what you get, buddy, you give what you get.

 

[john_316]

I want to let you all know though... If these experiments work with Burkhard Heims theories in the near future then I'll abandon this BDB proposal. Cuz a 5 hour trip to Mars sounds so much better. LOL <br /><br />Anyhow......<br /><br />Now for the moment my idea for this Clean Sheet Booster is if we can call it that is that it could also jump start private industry as far as in space processing of metals etc etc et al.<br /><br />Also the BDB can deliver a NTR with a Command Vehicle and a second launch to essemble a true SPACE CRAFT that would be reuseable in the solar system and only need to replentish water, food, crew, consumables and its fuel and nuclear core as needed and projected "much like a nuclear submarine" however this could also serve as the Mars Crew Vehicle and back. The craft is reused and recrewed as it transits the Mars-Earth plane during Mars-Earth Transits. <br /><br />This BDB design also could be used for the fabrication of large outer space structures, perhaps including a rotating space station with 1g gravity due to rotation in GTO/GEO/LO or what have you.<br /><br />This large station could also contain a mini-farm hydroponical garden or such things. So it truely could be a start of a so called space station that may have limited self sustainability to a degree at least food wise. This station could also be able to leave orbit using the slow propulsion power of ion engines. This could also allow a large crew to yes eventually tour the solar system over a few years and only have planned consumable visits as needed.<br /><br />This station could also be deployed to the inner asteroid belt as a jump start mining facilty where robotical equipment can start mining the asteroids of vital metals which can be processed in space and made into sheets and i-beams/tubular beams etc. of metal to build other structures in space.<br /><br />The idea of using alot of robotic equipment to mine, fabricate and assemble equipment in orbit or space would help in keeping a q

 

[edkyle98]

"If we used a clean sheet design and a heavy lift version with simplicity say RS-68 motors or even other versions (not really the subject here) can we build a booster like 2 extended ET types (actually ET sized clean stages) with the capacity to place in GEO and outfit it as needed say for a crew of 50+ that can stay in GEO for lets say over 30 days?"<br /><br />A rocket able to boost an empty ET's worth of mass (about 26 metric tons (tonnes)) to GEO would have to weigh more than 3,000 tonnes on the launch pad and perhaps more than 4,000 tonnes depending on the propellant choice. This rocket would weigh more than a Saturn V. I doubt you could do that with a rocket built around an ET core. <br /><br />On the other hand, it should be possible to build an all-liquid rocket around beefed-up ET based tankage. One back-of-the-envelope idea would be to build a two-stage rocket, with the first stage powered by four RS-68s and the second stage, which might be a stubby stage built with ET tooling, powered by four RL-60s. A rocket of this type might weigh about 995 tonnes at liftoff and be able to boost 50 tonnes to low earth orbit, twice as much as NASA's planned Crew Launch Vehicle (which will weigh nearly as much at liftoff). An optimized design, pulled off the envelope and run through a computer, should do even better. <br /><br />50 tonnes to LEO is pretty good. You could loft a small space station to LEO with that - something between Salyut and Skylab in weight. It would take two Delta 4 Heavies or 2.5 Ariane 5 ECAs or Protons to do the same haul. <br /><br /> - Ed Kyle

 

[danwoodard]

The closest any BDB concept got to flight was Beal Aerospace with a large Kerosine/hydrogen peroxide fueled booster. Although he put about $200M into it and had detailed launch site studies he had to pull the plug when no payload users (government or other) would commit to it.<br /><br />The RS-68, derived from the SSME but with only 10% of the parts and twice the thrust, is not designed to be reusable, but if you want the best (and only) example of a rocket using it, start with the Delta-IV. The common booster core is essentially an ET with an engine. As far as entirely US-designed rockets go, it is certainly the most advanced; the processing scheme is very efficient. Unfortunately its cost has been somewhat higher than the Zenit and Atlas-V (with Russian components). Nevertheless for the heaviest GEO or planetary payloads the Delta IV Heavy has the largest payload of any US booster, and its difficult to see how much more capability can be wrung from three RS-68s.

 

[edkyle98]

"The RS-68, ... if you want the best (and only) example of a rocket using it, start with the Delta-IV. The common booster core is essentially an ET with an engine. As far as entirely US-designed rockets go, it is certainly the most advanced; the processing scheme is very efficient. Unfortunately its cost has been somewhat higher than the Zenit and Atlas-V (with Russian components). Nevertheless for the heaviest GEO or planetary payloads the Delta IV Heavy has the largest payload of any US booster, and its difficult to see how much more capability can be wrung from three RS-68s."<br /><br />With its small upper stage, Delta IV seems to be optimized for geosynchronous missions, but it should be possible to better the Heavy design for Low Earth Orbit missions. For example, strapping three RS-68s to a single-barrel 500 tonne gross mass first stage topped with a 100 tonne gross mass second stage (powered by a more powerful second stage engine or cluster of engines) increases payload mass by 3 tonnes or so. The launcher would weigh 90 tonnes less than Delta IV Heavy at liftoff too, giving it a much more efficient intial thrust to weight ratio. <br /><br />RS-68 itself could be improved. One plan calls for the very heavy ablative nozzle to be replaced with a lighter regeneratively cooled nozzle. A Delta IV Heavy with a regen RS-68 could put almost 30 tonnes into LEO, as I recall. <br /><br />It would be nice if PWR could squeeze some more thrust from RS-68 too. For LEO missions, Delta IV Heavy seems to be thrust-to-weight limited.<br /><br />As for Delta IV itself, the rocket isn't necessarily a bad design, but the entire Delta IV system seems to have cost issues compared to Atlas V and ground crews seem to have to struggle more with their vehicles than Lockheed's crews do with Atlas V. Boeing's entire ground infrastructure for Delta IV, from production to launch, is excessive compared to Lockheed's for Atlas V. I still don't understand Boeing's launch processing str

 

[propforce]

<font color="yellow">"The RS-68, derived from the SSME but with only 10% of the parts and twice the thrust," <br /><br />And twice the weight of a SSME (7,000 pounds heavier) </font><br /><br /><br />... and one-fifth of the cost of a SSME <img src="/images/icons/laugh.gif" /> <br /><br />Wonder how much is the new J-2X is going to cost? <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> </div>

 

[mlorrey]

Ah, well, at one fifth the cost of an SSME but twice the thrust, this is certainly a viable alternative for my own 1.5 stage. Four installed below a single ET, with 3 in a ring around one central engine, and dropping the 3 at 65% of fuel burned, would give similar performance to my original design, without needing to spend anything on engine recovery. If the cost of each engine is indeed 1/5th that of the SSME, hmm, I'm going to spend some time with my spreadsheet.<br /><br />EDIT: While my original SSME equipped 1.5 stage booster, with operations to recover and refurb the SSMEs, would cost a bit of $22 million per launch, one equipped with the RS-68, using four engines at 1/5th the cost each, unreusable, would cost over $50 million per launch. While still significantly less than the EELV, it is more than double what recovery and refurb of the SSMEs would allow, even with SSMEs high refurb costs.<br /><br />It doesn't appear that the Delta IV common booster core uses an ET. Each CBC is narrower (I believe is 5 meters, not the 8 meters of the ET), and only has one RS-68 engine.

 

[propforce]

<font color="yellow">I thought it was more like a tenth ! </font><br /><br />It could be, but no one could tell me what the 'true cost' of a SSME is. <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> </div>

 

[propforce]

<font color="yellow">.... it is more than double what recovery and refurb of the SSMEs would allow, even with SSMEs high refurb costs. </font><br /><br />What is your assumption on the cost of recovery & refurbishing the SSME?<br /><br /><font color="yellow">It doesn't appear that the Delta IV common booster core uses an ET. Each CBC is narrower (I believe is 5 meters, not the 8 meters of the ET), and only has one RS-68 engine.</font><br /><br />Both the CBC (D-IV) and the CCB (Atlas V) are 5 meters diameters. But if you're planning a new launch vehicle, you can make them any diameter you want. An ET type diameter will save you cost of tooling, assuming you can buy the tanks from NASA (MAF is owned by NASA and operated by LM personnel).<br /> <div class="Discussion_UserSignature"> </div>

 

[propforce]

<font color="yellow">I was told 60 million US dollars but the throw away version is only 40 million. </font><br /><br />Thanks for the info.<br /><br /><font color="yellow">The Atlas V is 3.8 meters in diameter and the Delta IV is 5 meters in diameter. </font><br /><br />Thanks for the correction <img src="/images/icons/blush.gif" />. That's right, only the fairing is 5m. <div class="Discussion_UserSignature"> </div>

 

[mlorrey]

I set per engine refurb at $750k each, or $4.5 million per flight, and recovery cost of $1 million, plus amortization cost of a $5 million recovery vessel. I essentially took an estimate of what NASA would cost it out at, and divided by 20.

 

[mlorrey]

Private ventures to date, such as Scaled Composites and SpaceX, have developed their launchers for pittances compared to what NASA would cost identical programs at. Someone recently used NASA costing methods to cost out what NASA would budget for a SpaceShipOne program. It came out to $600 million. Given Rutan/Allen spent somewhere around $25-35 million on their program (and that Musk has spent proportionate amounts) indicates that NASAs costing methods are 20 times what private industry would do if they were doing it as a private venture to turn a profit, rather than on a cost+ contract for a government agency.<br /><br />This is reflected and further confirmed by LM/NASA studies I've seen of ET construction under the SLWT design which state that, depending on quantities produced annually, the cost of the Super Light Weight External Tank runs between about $600,000-750,000 dollars, yet NASA budgets $30 million per tank.<br /><br />So, given Scaled, SpaceX, and NASAs own ET internal costing studies, it is clear to me that there are immense amounts of pork that no profit-seeking business would tolerate if its program were run as an entirely private venture, rather than as a government contract.

 

[mlorrey]

The engines already reenter from orbital speeds on Shuttle. My pod system would detach around Mach12, half that speed, and rapidly decelerate under hypersonic drogues at high altitudes, thus would not be exposed to any greater thermal extremes than they already see with Shuttle.

 

[mlorrey]

Here is a NASA/Lockheed funded MIT study of cost optimising ET production done for the SLWT program:<br />http://lorrey.biz/library/STS_ET_Cost_optimization.pdf<br /><br />I can't find a link to the costing study I'd seen (it used to be linked by the wikipedia article on SS1, but someone has removed the cost comparison part of the article). I've done my own analysis comparing SS1 to the X-15 program, which, like SS1, had exactly two flights above 100 km by the same vehicle, one month apart from each other. The X-15 program, adjusted for inflation, cost $3.5 billion over a number of years for both altitude and speed research. The Mercury program, which involved a suborbital and a couple orbital flights, cost $600 million, adjusted for inflation (and with the subsidy of an already developed booster system that isn't counted in this amount). I think the 20 to 1 ratio is supported by quite a number of data points.

 

[propforce]

<font color="yellow">I set per engine refurb at $750k each, or $4.5 million per flight, and recovery cost of $1 million, plus amortization cost of a $5 million recovery vessel. I essentially took an estimate of what NASA would cost it out at, and divided by 20. </font><br /><br />Thanks. I also read your explanation that follows.<br /><br />You addressed the SSME refurbishment cost having been exposed to hypersonic thermal condition, however; you did not consider the additional cost for having been soaked in saltwater which would require a far greater effort to refurbish.<br /><br />Having been 'soaked' in saltwater means one has to take the engine completely apart, including the 4 turbopumps, flush every fuel/oxid/ purge/ pneumatic/ hydraulic lines and cavities to get rid of saltwater. Regen cooling tubes, channels, injectors and manifolds needed to be flushed as well. Electircal system needed to be taken apart, cleaned, inspected, and checked. <br /><br />Another O&M cost factor is the life of SSME, considering you take a still "red hot" engine and dip in the cold saltwater right away. Metals get thermal shocked and fatiqued quickly this way.<br /><br />So the analogy would be, for a formula-1 race car engine, to do oil change and inspection afterward vs. a complete teardown, flush, clean, reasemble and test.<br /><br />Another factor is, what will Rocketdyne charge you for refurbing the engine? Certainly not 1/20th of the current cost. I don't know if they will let you do them yourself, afterall they are very protective of their reputation. All engine companies would not let anyone, including the vehicle company guys, touch their engines.<br /><br /><br /><font color="yellow"> Given Rutan/Allen spent somewhere around $25-35 million on their program (and that Musk has spent proportionate amounts) indicates that NASAs costing methods are 20 times what private industry would do if they were doing it as a private venture to turn a profit, rather than on a cost+</font> <div class="Discussion_UserSignature"> </div>

 

[darkenfast]

Since this is a "clean sheet" BDB, here's what I would like to see in my Christmas stocking:<br /><br />A new, very large, LH/LOX engine (that's the "clean sheet" part). When I say large, I mean about 3 million lb thrust (hey, it's my stocking, isn't it?). The configuration of the launcher itself would would be similar to the Delta IV. The core and two strap-on's would be the same width as the CaLV (8m), however the core would be longer. The upper stage would be derived from the EDS. The shroud would be 10m in diameter. Although the overall thrust would be slightly lower than the CaLV, the payload to orbit would be higher due to the much-increased Isp of the strap-ons over the SRB-derived boosters. <br /><br />My real reason for wanting this is twofold. First, sooner or later we are going to have to get away from the toxic fuels, and obviously the LH/LOX mix is the way to go there. Second, even if we come up with a wiz-bang spaceplane follow-on to the CEV family down the line, we will still need the occasional big lifter for really massive objects. <br /><br />I wish to make it clear that I have absolutely no idea <br />if such a liquid-fuelled engine is possible, but I sure would like to see one!<br />

 

[propforce]

<font color="yellow">I wish to make it clear that I have absolutely no idea if such a liquid-fuelled engine is possible, but I sure would like to see one! </font><br /><br />We can't get you a 3M lbf thrust LOX/LH2 engine today, but would you settle for 3 engines at 1M lbf thrust each? <img src="/images/icons/wink.gif" /><br /> <div class="Discussion_UserSignature"> </div>

 

[darkenfast]

Sure, put it on my tab! Actually, the reason I was aiming for a new engine vs. clustering smaller ones was cost and efficiency (and "clean sheet" dreams). If nine smaller engines (which one are you referring to?) were to work out cheaper than three big 'uns (with development costs factored in over the life of that launcher), then, gee...twist my arm!

 

[mlorrey]

Okay, good points.<br /><br />Salt soaking:<br />a) I used to take a high speed boat racing in the salt water of Puget Sound. After each use, I'd hook some fittings up to the coolant intake and I'd hook a garden hose to it, turn on the water, then start the engine with the throttle off. This isn't hard.<br />Furthermore, when engines are shut down, fuel line valves will shut, and the pod will land nozzles up, given where the CG will be, so unless there is a storm or rain, the flotation devices and the valves should keep the engines from ingesting any salt water. The exteriors may need a hosing down.<br /><br />b) The reentry from 200,000 feet altitude the parachute ride will take, at a fall rate starting at 200 fps at first chute opening to 20 fps at sea level, should take several hours to return to earth. The SSMEs should return to ambient temperatures (especially given significant time in the stratosphere) by the time they return to earth. Thus, no thermal shocking. I didn't mention it because I thought it was obvious that the SSME wouldn't "dip in the cold saltwater right away". A parachute ride from the stratosphere takes a while.<br /><br />As for refurb costs: If I buy some SSME rocket engines, they are not Rocketdyne's rocket engines anymore, they are mine. The design of their parts is bought and paid for by the taxpayer, and the designs are all more than 20 years old, so there is no proprietary control of them or their parts designs.<br /><br />As for spendthriftiness, I would put it out as obvious that NASA is more interested in spending lots of money proving they are not wasting money, than actually spending less money getting things done.

 

[rocketman5000]

While the original design of the SSME are over 20 yrs old parts of the engine like the turbopumps have been updated over the years. I read about 2 years ago of a new casting technique that reduced the number of parts in the housing of the pump....

 

[mlorrey]

The last major overhaul was in the late 1980's following the Challenger investigation. Any patents for new parts from that period are public domain. The new turbopumps, yes, are rather new, but who owns the designs? Did NASA pay for them? If so, they are also public domain. The original SSME design is actually 30 years old. <br /><br />In any event, Rocketdyne can't even void the warranty if I did my own engine maintenance. It is against federal law to break a warranty over owner maintenance.

 

[propforce]

<font color="yellow">The last major overhaul was in the late 1980's following the Challenger investigation. Any patents for new parts from that period are public domain. The new turbopumps, yes, are rather new,...</font><br /><br />The latest is the Block II turbopumps made by Pratt & Whitney, which now is one company with Rocketdyne. <br /><br />Whether you can refurb engine on your own depends on the condition of sales. That will be a subject of negotiation between you and PWR, however; I am telling you what is the current practice today. I doubt you'll get much leverage negotiating with them, afterall; they're the only game in town.<br /> <div class="Discussion_UserSignature"> </div>

 

[propforce]

<font color="yellow"> Salt soaking: <br />a) I used to take a high speed boat racing in the salt water of Puget Sound. After each use, I'd hook some fittings up to the coolant intake and I'd hook a garden hose to it, turn on the water, then start the engine with the throttle off. This isn't hard. </font><br /><br />I am an avid ocean fisherman so I know about boat & engine care well <img src="/images/icons/smile.gif" />. It is not hard because the engine was designed to run in the saltwater environment, big difference from SSME.<br /><br /><font color="yellow">Furthermore, when engines are shut down, fuel line valves will shut, and the pod will land nozzles up, given where the CG will be, so unless there is a storm or rain, the flotation devices and the valves should keep the engines from ingesting any salt water. The exteriors may need a hosing down. </font><br /><br />Have you examine a schematic of SSME BTW? If you have, you'd notice that there're no valves at the inlet of SSME. The low pressure turbopumps are exposed to feedlines, as well as purge and pneumatic lines. Of course, this depends on how far up the vehicle feedlines would you separate the engines. <br /><br />You can not guarantee that no saltwater can get in from the nozzle, to the chamber and up the injectors to the manifold, and travel further up back flow to the high pressure turbopumps. For the simple reason that you can not guarantee the weather in Pacific Ocean. <img src="/images/icons/smile.gif" /><br /><br /><br /><font color="yellow">b) The reentry from 200,000 feet altitude the parachute ride will take, at a fall rate starting at 200 fps at first chute opening to 20 fps at sea level, should take several hours to return to earth. The SSMEs should return to ambient temperatures (especially given significant time in the stratosphere) by the time they return to earth. Thus, no thermal shocking....</font><br /><br />You're going to open the chute at 200,000 feet? <div class="Discussion_UserSignature"> </div>

 

[mlorrey]

Boat motors and rocket motors are made of metal. Are you telling me that rocket motor metals, made to withstand much higher temps and higher oxidizing environments, will be less durable to exposure to sea salt than a stock evinrude or cat? Gimme a break. Shuttle motors stand out in the open air exposed to atmospheric sea salt for months at a time. This is a bogus argument.<br /><br />Drogue chutes that open partly at supersonic speeds and expand as they slow down are long established. An SRB is much heavier than a pod of five SSMEs. Furthermore, given the low atmospheric density at high altitudes, and high density at low altitudes, anyone with experience with parachutes knows that the same chute has a higher drop speed at high altitude than at low altitude. Particularly, the speed at 50,000 feet is going to be ten times higher than at sea level since atm pressure at that altitude is less than 10% of sea level... .... I'm sorry if I don't keep stating the obvious, I assume that folks are bright enough to figure these simple things out for themselves.<br /><br />As for refurb tooling: I likely won't need to build my own (if I did, I have some excellent manufacturing engineers with aerospace industry experience on hand, thanks) refurb tooling, within a few years I'll be able to buy it all up at government surplus and scrap auctions....