ULV: the Ultra Heavy Lift Vehicle

[j05h]

What features would need to exist to make Ultra Heavy Lift Vehicles (ULV) work? What is Ultra Heavy Lift? What would be useful in terms of payloads and features?<br /><br />I'd categorize any rocket that can deliver over 200 tonnes IMLEO as being Ultra Heavy Lift, with the best proposals in the 400-500 ton to LEO range. This includes proposed, but never built rockets such as Boeing's LEO, Bono's ROMBUS and the gold-standard of ULV designs, the SeaDragon.<br /><br />We've discussed updated SeaDragons before, what got me thinking about ultra lift again was a conversation I had during the X Prize. A group of us were talking about reentry shapes and their tradeoffs. One of the guys said that capsules could never be used for bringing experiments, crystals and proteins back. We also talked about biconics, AndrewSpace's oblong capsule etc. This got me thinking about what I really am interested in for spaceflight. First is of course more human spaceflight. Second is how to move 40' cargo containers from the surface to LEO. <br /><br />The craft would be generally similiar to SeaDragon and Rombus, either TSTO or assisted-SSTO (droptanks). It would launch and land on the ocean or outer harbors of major cities worldwide, providing fast transit of cargo and orbital delivery in one craft. This ULV fits into modern intermodal shipping as the fastest means of heavy cargo delivery possible. Needs chips for your PC factory NOW? Call the guys at Xtreme Package Delivery, they'll have it there in under 4 hours. The craft is serviced at sea by either a ship & barge like SeaLaunch or (ideally) as part of a floating SeaHub. The ULV is refuelled with LOX and fuel (RP1, H but LNG fits nicely in operations terms) and serviced afloat. Containers would be handled internally on tracks or by crane and passed off to automatic dockside cranes. The ULV is tugged or self-propelled on the surface, self-stable at sea, and puts a lot of mass in orbit. It seemlessly fits into modern shipping and provides <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[Boris_Badenov]

I like this one better.<br /><br />Part 10: Prometheus would be proud of us.<br /><br /><br />In this section I describe a huge nuclear powered rocket launcher. I will repeat and expand upon many of the points I made above, because I don't want to throw cryptic acronyms around. I want people to understand just how powerful we can make this rocket if we decide to do it. <br /><br />The effective use of nuclear power in space transportation allows a paradigm shift in our thinking. All boosters which have been built to date have been shackled by the low efficiency of chemical fuels. Using chemicals it is possible to get off earth, but only barely. Every gram of structure must be trimmed, exotic materials and cutting-edge techniques are a necessity, and safety margins must be as slim as we dare if success is to be achieved. <br /><br />Nuclear power changes all that. Nuclear is VASTLY more energetic than chemical. We no longer must guard every gram of mass. Much more "margin" can be included. Much more safety can be designed into the machine. <br /><br />Let's examine a large heavy lift booster. There are other kinds of nuclear rockets we could build, but we desperately need a heavy lift booster if we are to excite people, catch their dreams, and actually do big stuff in space. <br /><br />The most powerful booster America has built to date was the Saturn V. The size and weight of the Saturn V are easily accommodated by existing infrastructure. <br /><br />Lets use the Saturn V as a "template" for a nuclear powered heavy lift booster. We will make the launcher roughly the same size, weight and power as the Saturn V, and let's see how the performance compares. <br /><br />The most important difference between our new booster and the Saturn V is in the engines. The Saturn V used five massively powerful F1 engines in the first stage, burning kerosene and liquid oxygen. The mighty F1 produced 1.5 million pounds of thrust. Despite its large size and power, the F1 was a very "relaxed" design <div class="Discussion_UserSignature"> <font color="#993300"><span class="body"><font size="2" color="#3366ff"><div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div></font></span></font> </div>

 

[gunsandrockets]

Thinking it through, you don't want toxic propellants, but you don't want cryogenic propellants either. Cryogenics would be a nightmare to insulate with the rocket dunked in the ocean, and what of ice build up? Hydrogen peroxide is a common choice but maybe something better is available.<br /><br />If you want the ultra simple big-dumb-booster that means pressure fed rocket engines. Bingo!<br /><br />Propane fuel and nitrous oxide oxidizer! They are non-toxic, non-cryogenic and best of all self-pressurizing. I'll have to search around to see if I can find ISP data for that combination of propellants, but I would guess an ideal vacuum ISP exceeding 300 seconds.

 

[j05h]

> Propane fuel and nitrous oxide oxidizer! They are non-toxic, non-cryogenic and best of all self-pressurizing. I'll have to search around to see if I can find ISP data for that combination of propellants, but I would guess an ideal vacuum ISP exceeding 300 seconds.<br /><br />Nice choices. Would that prop combination lend to a TSTO or assisted SSTO in the 500t range? Candidate propellant should either come in on ships (LNG) or be made onboard the processing facility.<br /><br />What are your thougths on using containers and the orbital/upper stage as extensible platforms beyond LEO?<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[nyarlathotep]

What you really need is a large lox/hydrocarbon engine. <br /><br />Actually we would already have a 400Mg+ launcher if the Soviets had let Glushko build his RLA-150. I'm sure it would have been feasible to slap on a LH2 cryo second stage with a half dozen airstart RD-0120's.

 

[j05h]

> What you really need is a large lox/hydrocarbon engine. <br /><br />That might work as well. I like the idea of using LNG since it's available already chilled and on ships. A tri-propellant SSTO or LOX+hydrocarbon TSTO seem like good possibilities. My real goal with the thread is to figure out what would be required (economically) to make ULV a flying reality.<br /><br /> /> Actually we would already have a 400Mg+ launcher if the Soviets had let Glushko build his RLA-150.<br /><br />Never heard of it, will look up. <br /><br />I'm mostly interested in how to make this work now, instead of rehashing old designs. What features would you like to see?<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[gunsandrockets]

"What you really need is a large lox/hydrocarbon engine."<br /><br />Maybe.<br /><br />For the gigantic type of launch vehicles being discussed in this thread, launch facilities become a crucial factor. Recall that barges were needed to transport the large components of the Saturn V, plus the enourmous VAB to put it together, then the giant crawler pad to move it into launch position.<br /><br />That's why the sea launch concept is so promising. Build the giant rocket in a dockyard, tow it out to sea, gas it up from tanker ships, then light it off! The headaches from operations at sea are worth it to avoid the headaches of operating a giant vehicle from land.<br /><br />One of the headaches of operating at sea is thermal control problems. <br /><br />A land launched rocket stage holding cryogens such as LOX, in contact with the air, transfers a lot of heat which increases the boiloff of the propellant. And the cold tankage condenses water out of the air into ice which clings to the rocket stage.<br /><br />Now imagine the same cold rocket stage dunked in the ocean! All the thermal issues just got much much worse. Water transfers heat much worse than contact with air. Add to that problem the additional problems of storage and transfer of cryogenic propellants at sea from the tankers into the empty rocket stage. No thanks.<br /><br />The simple way to avoid problems like that is to ditch cryogenic propellants and switch to room temperature propellants for sea launch.<br />

 

[gunsandrockets]

"I'm mostly interested in how to make this work now, instead of rehashing old designs. What features would you like to see?"<br /><br />I think an ideal location for a dockyard to construct a sea launched ULV would be the East coast of India.<br /><br />After completion the ULV could be towed out into the Bay of Bengal for launch. The advantage of this is the low latitude of the launch location, giving the ULV the maximum delta V benefit from the spin of the Earth.<br /><br />And maybe construction costs would be cheaper in India too!

 

[gunsandrockets]

"What are your thougths on using containers and the orbital/upper stage as extensible platforms beyond LEO?"<br /><br />I think a standard shipping container is probably mass inefficient.<br /><br />Reusing the upper stage which reaches orbit as a 'wet tank' habitat has some merit. Reusing the stage as an orbital fuel depot has even more merit. But a big-dumb-booster will have plenty of inefficiencies without adding design compromises for orbital reuse. It could go either way.<br /><br />My own preference is to keep the booster simple and cheap. And that means using it as a cargo only launcher. That way some corners could be cut. <br />

 

[gunsandrockets]

I am a big fan of Nuclear Thermal Rockets. Heck, I'm a big fan of the Orion nuclear pulse drive 'doomsday' spaceship! (It's funny how the Orion concept provokes raging fits from some people).<br /><br />But I think you are barking up the wrong tree trying to use nuclear propulsion, and in particular gas core nuclear propulsion, for a 1st stage rocket booster.<br /><br />The problem is (aside from exotics such as Orion or Zubrin's salt water rocket) high ISP nuclear thermal propulsion doesn't have adequate thrust to weight ratio for a 1st stage rocket booster. The rocket wouldn't even get off the ground!<br /><br />Check out this link for an excellent overview of various nuclear propulsion systems including estimated thrust to weight ratios...<br /><br />http://www.fas.org/nuke/space/c07sei_2.htm<br /><br />Now if you wanted to use nuclear propulsion for an upper stage, that is an entirely different matter. That is where NTR can really boost the payload of a launch vehicle, turning something like the Saturn V into an ULV!<br /><br />Try this...<br /><br />Take the proposed NASA Ares V HLV, and change out the core stage with it's five LOX/LH2 fed RS-68 engines. Instead the core stage is all liquid hydrogen tankage (cutting the weight of the stage by 80%) and the engines are five NERVA-1 nuclear rocket engines which produce a total of 375,000 pounds of thrust. This nuclearized Ares V launcher should be able to put more than 260 tonnes payload into LEO or more than double the payload of the regular Ares V cargo launcher.

 

[j05h]

> I think a standard shipping container is probably mass inefficient. <br /><br />The model I'm pursuing would involve most of these superboosters being used for point-to-point cargo/passenger delivery. This would be followed by a (potentially large) secondary market in placing mass onorbit. My starting point was how to make ULVs financially viable and fast-transit of standardized containers seemed to make the most sense. <br /><br /> /> Reusing the upper stage which reaches orbit as a 'wet tank' habitat has some merit. ...It could go either way. <br /><br />I'd like the vehicle itself to be simple, robust and overengineered. The uses I see for it would largely be follow-ons that hack a very simple system. The basic upper stage has a cargo bay (container-capable or not) plus access to tankage and engines. It can carry people in sparse accomodation, or a pimped-out Hab can be installed or carried in the hold. With a 16-container sized hold you could inflate full Nautilus modules inside, kit them out and test them in shirtsleeves before deploying them. In the same way that old factories are "universal space", I'm picturing the basic vehicle as having all sorts of uses because it is utilitarian. <br /><br />If the upper stage of a ULV could be refueled onorbit it would make an interesting exploration/construction platform. You can build the SPS while living in a relatively large habitat. The craft already has engines and thermal control. I had been picturing crew living in a large (15', 10ish crew) capsule docked into the main vehicle and in the cargo hold. If living in the tankage makes sense, it'd be that much more space. Another use for the tankage would be storing extracted resources. <br /><br />Being able to store up to 500tons onboard means carrying all sorts of extra equipment: you really can start talking about nuclear bulldozers once this kind of craft is flying. <br /><br /> /> My own preference is to keep the booster simple and cheap. And that means using it as a <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[nyarlathotep]

<font color="yellow">Could the F1 be repurposed (and revived) to fly with LNG and nitrous?</font><br /><br />No. There are also no F1's, and it wasn't a particularly good engine (from both a cost and mass efficiency standpoint) to begin with. N20 isn't a particularly good oxidiser. You're better off going with lox and losing some payload to insulation.<br /><br />I'm not sure the optimum size before hoop stress starts getting in the way, but a large pressure fed Sea Dragon type vehicle (say 1Gg+ payload) would probably need to have a hundred or so combustion chambers.

 

[bpfeifer]

I think one of the greatest costs in spaceflight is due to the custom work that occurs with every flight. Part is related to ground crew, but a large part is also incurred during redesign and construction. <br /><br />You’ve been talking about building it in a shipyard, which evokes images of hundreds of workers running around with welding torches. You may want to consider automating as much of the construction process as possible. That is the greatest advantage to using a standardized design. Even large structure fabrication could be automated if it is designed with automation in mind from the start. Grab some Japanese engineers. They are the best at designing fabrication robots and making designs suitable for automated construction. <div class="Discussion_UserSignature"> Brian J. Pfeifer http://sabletower.wordpress.com<br /> The Dogsoldier Codex http://www.lulu.com/sabletower<br /> </div>

 

[nyarlathotep]

<font color="yellow">You may want to consider automating as much of the construction process as possible. That is the greatest advantage to using a standardized design. Even large structure fabrication could be automated if it is designed with automation in mind from the start.</font><br /><br />Otrag scaled up by an order of magnitude would probably fit the bill.

 

[j05h]

<i>> I think one of the greatest costs in spaceflight is due to the custom work that occurs with every flight. Part is related to ground crew, but a large part is also incurred during redesign and construction. </i><br /><br />What I'm talking about is separating segments of the flight to different operators and building big to force economies of scale from the start. The system I favor conceptually would be TSTO with the upper segment owned by a separate provider than the lower stage and surface infrastructure. The upper stage can be customized to your (operators) needs while the lower stage pop-up booster provides a consistent amount of lift. It spreads the costs further and creates a more robust transportation system. This can start as a fast point-to-point system and evolve outward. Build a really robust and simple (floating, pressure fed, LoX and LNG) lower stage then put all your mission hardware on a customized upper stage. Yes, it's ship sized, it will be costly per craft, but they do ship-like things. I favor a basic upper stage that serves modular cargo delivery throughout cislunar space, using different cargo modules. The overall architecture would allow for other, custom upper stages. Building big creates economies of scale, for the same reason that we have airliners and cargo ships. The first stage's boost is enough to get most of the way to orbit, the upper stage either finishes the burn or performs a suborbital arc to surface destination.<br /><br /><i>> You’ve been talking about building it in a shipyard, which evokes images of hundreds of workers running around with welding torches. You may want to consider automating as much... Grab some Japanese engineers. They are the best at designing fabrication robots and making designs suitable for automated construction.</i><br /><br />Modern American shipyards have some automation as well. Don't discount local talent, I am thinking of projects like Bath Iron Works' recent "Mega Unit" hull segment. Automatio <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[j05h]

<i>No. There are also no F1's, and it wasn't a particularly good engine (from both a cost and mass efficiency standpoint) to begin with. N20 isn't a particularly good oxidiser. You're better off going with lox and losing some payload to insulation.<br /></i><br /><br />"Whatever works." I'm for LOX if it makes things simpler overall. The goal is to build big enough to enable extremely large orbital payloads. If different fuels makes sense for the upper and lower stages, that works too. <br /><br /><i>I'm not sure the optimum size before hoop stress starts getting in the way, but a large pressure fed Sea Dragon type vehicle (say 1Gg+ payload) would probably need to have a hundred or so combustion chambers.<br /></i><br /><br />Boeing's "LEO" used 16 or 32 chambers around it's outer perimeter. I'm interested in engines like TRW's 650k pintle injector engine, but able to burn multiple fuels like LNG and methane. <br />http://www.space.com/businesstechnology/technology/trw_rocketengine_000926.html<br /><br /><i>Otrag scaled up by an order of magnitude would probably fit the bill.</i><br /><br />That could work for the lower segment and/or as additional delta for the upper stage. Otrag was a very interesting concept, bummer about where it was built. The cores would have to be collected, though, at the flight rates this system would support an Otrag-derived design would produce a lot of litter. Without better numbers I tend to favor a monolithic pop-up booster and custom upper stage "ships'. How would hundreds of Otrag sections be processed, and can that work at sea, or does it make the system land-based?<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[nyarlathotep]

I'm not a rocket scientist (I majored in physics and economics with a minor in geology), so I don't know where to start with the cost trades for reuse. In heavy mass production I expect that it would be much easier and cheaper to just let them sink to the bottom of the ocean than to fish them out and refurbish them. A little residual kerosene and nitric acid isn't going to harm anything and in a decade or so they'll end up making a good reef.<br /><br /><font color="yellow">How would hundreds of Otrag sections be processed, and can that work at sea, or does it make the system land-based?</font><br /><br />I imagine they would be assembled at the pad with a VAB sized gantry crane and then bolted or welded together. Otrag could probably be made to work on a _very_ large mobile platform like sealaunch, but I think it would probably be a hell of a lot cheaper to use Johnston Atoll or Kiritimati Island. <br /><br />Kiritimati is particularly interesting as it's smack on the equator, already has a NASDA tracking station (planned for use with HOPE-X), has a large underemployed subsistance level workforce, no natural resources, and large groundwater salination problems. They're going to be a whole lot more welcoming to a spaceport than the population of the Caribbean Islands as Beal unfortunately found out late into his plans. <br />

 

[j05h]

<i> > I'm not a rocket scientist (I majored in physics and economics with a minor in geology), so I don't know where to start with the cost trades for reuse. In heavy mass production I expect that it would be much easier and cheaper to just let them sink to the bottom of the ocean than to fish them out and refurbish them. A little residual kerosene and nitric acid isn't going to harm anything and in a decade or so they'll end up making a good reef. </i><br /><br />I'm not a rocket scientist either, I'm an artist. I have to trust other peoples numbers, otherwise it's all instinct. Proton launches have spoiled water and land resources in parts of the former USSR. Looking back on some of the 1960s mega-boosters it seems like the next logical step. The space elevator is (realistically) generations away, we are already outgrowing the current rocket paradigm. Let's build Big. <br /><br />The main hold of the upper stage, following my "16 containers" concept above would be about 35x35x40 feet. It's quite large, and once you can afford to pack one and refuel it onorbit, you can begin to do some extraordinary things. Alternatively, 500 tons of factory, SPS or habitat builds a lot of stations and exploration craft. <br /><br /><i> > I imagine they would be assembled at the pad with a VAB sized gantry crane and then bolted or welded together. Otrag could probably be made to work on a _very_ large mobile platform like sealaunch, but I think it would probably be a hell of a lot cheaper to use Johnston Atoll or Kiritimati Island.</i><br /><br />So this would be for a single site to orbit launcher. I'm talking about starting with a network of boosters across the world, connecting major manufacturing hubs directly, then expanding with other upper stages for LEO and beyond. The flight rates needed to support this system would (in Otrag format) mean thousands of stages worldwide every year. As a single site vehicle it makes more sense. <br /><br />There are several good equatorial islan <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[publiusr]

I am very glad to see Heavy-Lift finally being accepted in the spaceflight community, as interest in fanciful SSTOs, Space Elevators, etc.-- at last begins to wane.

 

[j05h]

<i>> I am very glad to see Heavy-Lift finally being accepted in the spaceflight community, as interest in fanciful SSTOs, Space Elevators, etc.-- at last begins to wane.</i><br /><br />So, what features would you like to see in an Ultra-lift architecture? The design I'm talking about would evolve from a heavy ballistic harbor-to-harbor transport into a TSTO craft that can service cis-lunar space and beyond. The main measure was to carry 16 40' containers (about 450t plus), but others didn't really pick that part of the discussion up. Fitting seamlessly into the intermodal shipping system gives a foundation for building further space access. Containers might be mass-inefficient to LEO but would be able to provide stock metal or built into cheap (re: dangerous) hab, garage, storage onorbit or other planets. Following ROMBUS, drop tanks would be added to the basic vehicle if needed, to make a SSTO-and-a-half or to enhance a TSTO. We also discussed using LNG for fuel to simplify logisitics. The goal would be to build as big as possible to enable robust construction, preferably in a shipyard, using steel, CF, large engines, and eventually building space ships instead of tin cans. There is a place for capsules/spaceplanes in this as well: as the bridge of the craft.<br /><br />Any ideas on this concept or others? Nothing below 250t throw weight, please. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[docm]

TeamVisions Jupiter-III sounds good.<br /><br />http://www.teamvisioninc.com/services-consulting-space-exploration-optimization.htm<br /><br />http://www.teamvisioninc.com/downloads/AIAA-2006-7517-146.pdf<br /><br />200-500 MT (pg. 45 of PDF) <div class="Discussion_UserSignature"> </div>

 

[gunsandrockets]

"The design I'm talking about would evolve from a heavy ballistic harbor-to-harbor transport into a TSTO craft that can service cis-lunar space and beyond. The main measure was to carry 16 40' containers (about 450t plus), ... Fitting seamlessly into the intermodal shipping system gives a foundation for building further space access."<br /><br />"...but others didn't really pick that part of the discussion up."<br /><br />True, true I didn't focus on that. But there is a fundamental flaw in the idea of using a heavy lift vehicle for suborbital commerical transport as you suggest. Even if the suborbital transport was a reusable vehicle, something that in my opinion would greatly complicate what should be a super simple big dumb booster, the turnaround time (or cost) vs payload would not enable the vehicle to compete against existing commercial cargo aircraft.<br /><br />Think of everything involved in flying a port to port spacecraft. To avoid dragging the spacecraft to and from a port loading dock a huge sea based infrastructure would be neccessary to load/unload, inspect and repair the spacecraft between flights. And that infrastructure would have to be built at every point of destination! That's too expensive too compete with cargo aircraft. Alternatively the spacecraft should be dragged into port and then dragged back out to sea again for launch, that is a practical economy of operations but then the turnaround time is too slow to compete with cargo aircraft.<br /><br />You could base your super heavy transport purely on land, but that then means providing the launch and recovery infrastructure for handling super heavy/large stages on land. Think of what was involved with the Saturn V launch vehicle. And even then the Saturn V still had to make use of barges to move around equipment. And you would again have to build this infrastructure at every point of destination. That could not compete economically with cargo aircraft.<br /><br />Aside from commercial mission

 

[j05h]

For a servicing structure, I am assuming a 'SeaHub' structure that can fuel, load and unload the ULV. Ideally, the priority containers would have a fast-ferry hovercraft or similiar. THe craft is explicitly modular, it might carry passengers along with cargo. Maybe there isn't a suborbital market. What do you think of a ROMBUS/SeaDragon/LEO-type ULV that can service all of cis-lunar space? Instead of passing off to a tug, the entire craft could be refuelled in orbit and flown to the Moon or even NEOs and Mars. <br /><br />I"m all for the USMC developing an Aliens-style dropship. It's totally something they would do. I'm also for whatever other space-based systems the DoD wants, as long as it brings about cheap, accessible spaceflight for the rest of us. <br /><br />Where do you see a market for ULV emerging? <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[scottb50]

Nice art work, but still an expendable. What I have in mind is a range of vehicles, using the same architecture, with various capabilities. It starts with a Common Module that uses two basic parts. The parts can be built in different sizes with various detail configurations and different materials as needed.<br /><br />The base vehicle would use six Common Modules for the first stage and two for the second stage. Payloads would be in the range of 20 passengers or 10,000 pounds of cargo in a return vehicle, similar to the X-37, or a 20-40,000 pound payload in a non-returnable Common Module container.<br /><br />The first stage uses two LH2 tanks, two LOX tanks and two SRB housings along with a light weight aerodynamic shell. The second stage uses one LH2 tank and one LOX tank.<br /><br />Each LH2/LOX stack has a single SSME and the SRB's use fixed nozzles.The upper stage, with a single engine, rides to release but can power away from the first stage in an emergency giving a passenger vehicle enough altitude and velocity for safe return<br /><br />A heavy lifter would use eight Common Modules, four SSME's and two SRB's, for the first stage and four Common Modules, with two engines, on the second stage putting 100,000 pounds into orbit in a non-returnable Common Module. <br /><br /><br /><br />The first stages would be flyback boosters and the second stages would remain in orbit, being used as Tugs or being dismantled and the Modules used as building material to expand Stations or build lunar or other vehicles, as well as surface structures on the moon and beyond.<br /><br />Using the common architecture each LH2 tanks would use four outer Segments and a single inner Tube and the LOX tanks would use two outer Segments and a single inner Tube. The SRB Housings would use five outer Segments and a single Tube each. <br /><br />Two basic pieces, with different detail configurations, that could be mass produced by the thousands for any number of uses beyond Space. Low cost accumulators <div class="Discussion_UserSignature"> </div>

 

[brellis]

What happens to the ozone layer when one of these great beasts goes roaring through? Does it burn a big hole in it? <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>