Space Plane Concept Forgotten?

[qso1]

I wouldn't doubt Orion will be safer. But thats in part because capsule spacecraft designs are simpler. I don't put a whole lot of stock in risk numbers regardless of spacecraft design. My point was that the shuttle has been very forgiving. Those numbers could have been a lot worse for shuttle. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[halman]

Redstone_1, et al,<br /><br />Something which should be kept in mind in discussions such as these is that the engineers at NASA back in the early 1970's had plenty of experience with capsules, knew their capabilitites and drawbacks, knew the penalties involved in a lifting body design, and yet, still chose a lifting body for the initial design of the Space Shuttle. Some people will say it was politics, to keep the aerospace industry happy, to which I say "there has to be an aerospace industry if we are going to be going into space." Some people say that the Air Force requirements drove the design, to which I say "NASA chose a lifting body BEFORE the Air Force climbed on boad."<br /><br />What NASA wanted was a two stage to orbit spaceplane, with a modest payload capacity, for hauling people back and forth from orbit. The heavy lifting would be done by rockets, such as the Titan IIIC, which was not man-rated, due to the solid rocket boosters. The first stage would have been a liquid fueled, flyback booster, quite possibly a flying wing. It would have carried the orbiter to a high enough altitude that Max-Q would not be a problem, and then seperated, flown back, and landed on a runway. Turnaround time on the booster would have been very short, so a small number of boosters would have kept a fleet of orbiters flying frequently. These orbiters would be for short trips to Low Earth Orbit only, in support of a space station, and eventual return to the Moon.<br /><br />Economy of scale is that principle which makes it possible for us to have mass produced goods at affordable costs. If each Boeing 747 was built from an original set of plans, to individual specifications, there would be no 747s. NASA insisted that at least 7 orbiters would have to be built if the projections for launch rates were to be met. Congress chose to ignore the engineers and use its own brains to decide on the number of orbiters.<br /><br />Both the Challenger and the Columbia were lost because of <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[willpittenger]

You misread my post. I stated the <i><font color="yellow">Direct Ascent</font>/i> method of landing on the moon died quickly. I said nothing about DC-X's death. You had suggested that a Delta Clipper-like could land on the moon. Sure, it could land in a lot of places. However, that system was rejected in the early 1960's.</i> <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[j05h]

> The best minds at NASA believed that a spaceplane was the next step ...snip... there is widespread belief that the spaceplane is inherently flawed ....snip... Even if we return to using capsules, it is likely that spaceplanes will fly again, because landing on a runway is the only way to have a regular schedule that passengers can rely on.<br /><br />Spaceplanes have been repeatedly proven (X15, X24series, STS, SS1) but my criticism is against the Shuttle for the usual reasons. X-15 was one of the most successful spacecraft ever, even if it was suborbital. Scheduled landings are possible on a Helipad-type structure with capsules, or in a dedicated dropzone with fast recovery. I think a landing pad with a big "C" on it would look cool - you'd need parasails on your craft for this. Returning spacecraft are going to have somewhat different tarmac requirements than ordinary aircraft so a normal runway and terminal might not be the best solution even with spaceplanes. Mojave/Edwards is only a short flight to LA, but far enough away to test and deploy many potential spacecraft. <br /><br />I understand that part of what you are talking about is the old Pioneer Astronautics concept: leaving and returning spacecraft would just enter normal air-traffic control below 60k ft. Pinpoint landings on scheduled craft will happen, but it's still a ways in the future. For now, space travellers have to settle for landing in/near a wide open space. <br /><br />The rest of your analysis is spot-on.<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[rocketman5000]

I found it interesting that the DC-X used graphite epoxy liquid hydrogen tanks. The same sort of construction that failed in the X-33

 

[j05h]

>I found it interesting that the DC-X used graphite epoxy liquid hydrogen tanks. The same sort of construction that failed in the X-33<br /><br />Spherical tanks are a lot simpler than noncormal tanks. Not sure, but I don't think the composites on X-33 were graphite-based. There could have been very different reactions depending on liners used and variants in materials. <br /><br />Did anyone check out AMaRV?<br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[PistolPete]

Yes, but those tanks on the X-33 were of a very unconventional shape, and they also formed a load bearing part of the airframe. The ones on the DC-X were just simple cylindricall tanks and (AFAIK) not load bearing structures. The X-33 tanks failed under stress tests and it was determinded that the fix would have weighed more than aluminum ones. That was the last straw on the camel's back, a few weeks later, the program was canceled. <div class="Discussion_UserSignature"> <p> </p><p><em>So, again we are defeated. This victory belongs to the farmers, not us.</em></p><p><strong>-Kambei Shimada from the movie Seven Samurai</strong></p> </div>

 

[halman]

JO5H,<br /><br />I am not trying to be an obstructionist, I just want to point out that (and I have no way of documenting this, but I think it to be true,) one of the reasons that the NASA engineers decided to make the huge technical leap to a spaceplane was the public sentiment against throwaway launch vehicles. I remember the indignation expressed by many people that the huge Saturn 5 rocket was discarded on each Apollo mission, and explanations about the costs of reusability were usually met with blank stares. <br /><br />Even though capsules and service modules are specified to be reusable, they will make up a small fraction of the rocket the public watches launch on TV. We are likely to have the same battle on our hands as before, irregardless of the actual cost of the rocket. For this reason, I would like to see at least a design study on the original shuttle proposal, as a backup in case public opinion becomes a serious obstacle to space access. I was elated when Burt Rutan described a White Knight carrier with 8 747-size engines, because that has potential to carry an orbiter, in my opinion. <div class="Discussion_UserSignature"> The secret to peace of mind is a short attention span. </div>

 

[qso1]

Sorry. I had no idea you were referring to a lunar lander. The direct ascent plan for going to the moon was rejected largely because of the vehicle that was needed to just get it on its way. A launch vehicle design called Nova was being studied for direct ascent to the moon. Several versions were proposed. The Saturn was under development then as well. The earth orbit rendezveous method was favored for Apollo till an obscure engineer named John Houboult proposed the adapted lunar landing method in 1962.<br /><br />The direct ascent spacecraft got rejected with the Nova and had it been developed, would have been substantially larger than the Delta Clipper. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[qso1]

The difference was the complex shape of the X-33 tanks. This may have played a role in the tank problems with the X-33. It should be noted the X-33 designation applied to both vehicle concepts. The Delta Clipper was the McDonnel Douglas version while the X-33 was Lockheeds version. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[willpittenger]

<blockquote><font class="small">In reply to:</font><hr /><p>Not sure, but I don't think the composites on X-33 were graphite-based.<p><hr /></p></p></blockquote><br />I do not know the exact material, but they were composite -- and a very unusual shape. The shape was the main cause of the failure. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[willpittenger]

Actually, if it had not been for the Sputnik public relations disaster, we might have continued to follow the X-15 concepts with more advanced spaceplanes. X-20? Maybe. More likely an X-20 that with no need of a vertical launch. I figure a B-52 or something similar (747?) might have carried it up to a launch altitude. As such, maybe we would not have reached the Moon yet, but our launchs would better planned and possibly safer.<br /><br />In the end, which route is better? You would be judging it with 20/20 hindsight. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[qso1]

willpittenger:<br />In the end, which route is better? You would be judging it with 20/20 hindsight. <br /><br />Me:<br />Absolutely.<br /><br />Unfortunately the shuttle will probably doom spaceplanes for a long time. The real problem IMO is that we are limited by budget. To me, the ideal combo is a spaceplane that launches from a rocket, or as willpittenger pointed out, aircraft launched. And heavy lift rockets for the big jobs. But what has actually happened is budget has limited us to capsules on the human launch side. Capsules are easier than winged vehicles to develop as demonstrated by NASA attempting to develop winged vehicle successors to the shuttle but giving up in the end and going capsule.<br /><br />The VSE could just as easily been a program where the CEV element would have been an HL-20 type vehicle rather than a capsule. But the HL-20 type vehicle is a costlier development program. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[qso1]

You mentioned 747 launched. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[qso1]

These are from my graphic novel series and as such, are not meant to indicate that such a vehicle would actually work. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[docm]

All this misses one thing: the idea is to get people to/from LEO. That's it. Wings make no sense for anything other than the last 5% of the mission, so why launch all that extra weight when something simpler will do the job? They certainly make no sense for lunar or planetary missions.<br /><br />Capsules like Dragon etc. are in keeping with this idea, which unfortunately is something govt. projects often ignore; the K.I.S.S. principle (keep it simple stupid). The shuttle certainly failed that test, and it cost 2 crews too boot. <br /><br />Every shadetree mechanic out there who follows the space program has figured this out, but we still have people who want X-Wing fighters to do a job better suited to something far less complex <img src="/images/icons/tongue.gif" /><br /><br />As for the reasons for going spaceplane in the 70's; the main one sold to the public was a side effect of the environmental movement: recycling. The idea was why 'waste' all that expensive hardware that burns on re-entry when you could recycle the SRB's and spaceship, making spaceflight 'cheaper' and more 'environmentally correct'.<br /><br />Well, we all know how <b>that</b> turned out.<br /><br />IMO we need two <b>capsules</b>: one low cost capsule that carries 6-8 passengers to/from LEO and one capable of direct high speed re-entry from lunar/planetary missions. <br /><br />If they're high/lo track developments from LockMart or a mix of Dragon etc. and Orion fine. Just no more overblown pieces of govt. bloatware like the Shuttle. <div class="Discussion_UserSignature"> </div>

 

[qso1]

The idea is to get people to LEO on a cost effective basis. Capsules may be relatively inexpensive but launchers are not. Launchers are also limited to the ground facility locations. In the U.S. there are two primary locations for launching vehicles large enough to carry people. KSC and VAFB. They are the only ones because of launcher flight rates, costs, and range safety issues.<br /><br />One should look at the winged vehicle concept for what it can offer. I showed mine here and for what little I showed...two things should be evident. Launch location is one...the 747 is over the ocean which means most any coast with ocean to the east and a 747 capable airport less than 200 miles from the launch site will do.<br /><br />Of course, the airport will have to have facilitation for checkout and fuelling of the orbiter.<br /><br />The carrier craft itself...off the shelf 747 with only the mods required to launch the orbiter which in this case, I call a wedge.<br /><br />docm:<br />Capsules like Dragon etc. are in keeping with this idea, which unfortunately is something govt. projects often ignore; the K.I.S.S. principle (keep it simple stupid). The shuttle certainly failed that test, and it cost 2 crews too boot.<br /><br />Me:<br />The very first capsule mission in the Apollo program cost us a crew. This is not a reason to reject winged vehicles. Fact is, we may one day loose a crew in a CEV. Both designs can only be made so safe. Spaceflight is an inherantly dangerous business as long as chemical rockets are used.<br /><br />docm:<br />As for the reasons for going spaceplane in the 70's; the main one sold to the public was a side effect of the environmental movement: recycling. The idea was why 'waste' all that expensive hardware that burns on re-entry when you could recycle the SRB's and spaceship, making spaceflight 'cheaper' and more 'environmentally correct'.<br /><br />Me:<br />I've never seen an official position that stated green concerns for developing the shuttles. The reason r <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[docm]

1. capsules can be launched from aircraft too. Visit the t/Space and Scaled Composites sites for how.<br /><br />2. you read different materials than I did in the 70's then. That 'airliner' and 'space truck' stuff was the subtext. The main point was reusability and its supposed cost savings, which of course was pure, unmitigated BS.<br /><br />3. boosters: see SpaceX. If Falcon 9/Dragon works that blows the cost/launch arguement to hell. It's an 'if', but the benefits of success are very high. There are even analyses out there that man-rated Atlas V 401's could go down to $70M/launch with frequent launches (the current $138M is largely due to fixed costs + infrequent launches).<br /><br />4. Apollo burned on the pad, not in space, due to a faulty <i>internal</i> design that would have bkilled people no matter the external shape. <br /><br />The Shuttle has failed twice in the air; once due to a poor SRB seal design coupled to arrogant/stupid launch officers and once due to a weakness pointed out before it ever flew. The latter is one inherent to spaceplanes: hotspots on the leading edges. One small defect and you're toast...literally.<br /><br />Either way NASA and independent number crunchers put capsules dozens of times safer than the only operational spaceplane. That alone is enough for me.<br /><br />Give me a nice, simple semispherical heatshield every time.<br /><br />Remember: K.I.S.S. <div class="Discussion_UserSignature"> </div>

 

[qso1]

docm:<br />1. capsules can be launched from aircraft too. Visit the t/Space and Scaled Composites sites for how.<br /><br />Me:<br />This is an as yet unproven concept, that is...it has not actually been demonstrated repeatedly operationally. More than likely it will work but the important question is, how economical will it actually be? Now assuming that it all works, then capsules will be the way to go for sure but only for smaller payloads. One reason for my concept as illustrated is that larger payloads will require either larger capsules...or winged/lifting body solutions.<br /><br />docm:<br />. you read different materials than I did in the 70's then. That 'airliner' stuff was the subtext. The main point was reusability.<br /><br />Me:<br />And I still have much of my 70s materials. Your statement above is correct where reusability is concerned. But reusability was mentioned in most of my materials in the context of rockets being too costly to throw away with green concerns and recycling being occassionally mentioned by some book authors but no official positions I can recall. In fact, one example that was made was "Imagine throwing away your cheap VW everytime you go to the 7-11, thats what we did with rockets, even relatively cheap Scout rockets are thrown away". The airliner stuff was indeed subtext, subtext designed to convey the benefits of airliner operation to the lay public and comparing the shuttle to the DC-9 in physical size and airliner operation was one way of doing this.<br /><br />docm:<br />3. boosters: see SpaceX. If Falcon 9/Dragon works that blows the cost/launch arguement to hell. It's an 'if', but the benefits of success are very high.<br /><br />Me:<br />This argument is only blown when enough of these rockets can be successfully and economically operated. But more importantly, recall I mentioned rocket costs in the context of a NASA/contractor arrangement. In the context of privateenterprise/industry ops...the situation may be and hopefully will prove. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[docm]

Then you agree that the public was fed the re-usability pablum. Good, then that's settled.<br /><br />Yes, most of the commercial ideas need proving but they are sound concepts. The drop tests done by Scaled Composites show that. <br /><br />IMO the spaceplane concepts first test series (STS) is nearing completion and has shown to be overly complex, relatively unsafe, uneconomical and hard to maintain. <br /><br />If it were a car it would be the Edsel.<br /><br />Perhaps something like Dream Chaser (an updated/modded HL-20) will work, but I wouldn't ride it in the first 100 flights. OTOH a capsule would be tempting.<br /><br />BTW: that concept you posted shows an X-33 type vehicle. I thought with the tank problems and the linear aerospikes power being sub-par other configurations were more viable (ie: Dream Chaser etc). <div class="Discussion_UserSignature"> </div>

 

[qso1]

docm:<br />3. boosters: see SpaceX. If Falcon 9/Dragon works that blows the cost/launch arguement to hell. It's an 'if', but the benefits of success are very high.<br /><br />Me:<br />Not entirely. I grew up with the shuttle. I kept many of the magazines from the 1970s that touted reusability of the shuttle. The fact is, shuttle is, and has been reusable. It has not been reusable on an economic basis. From a 1973 Saturday Evening Post I still have, shuttle had just been frozen in the design we all know today. It actually was the design that preceeded the one we know. The traffic model called for 60 flights per year between 7 orbiters. The reusability was a sound reason for developing it. Nobody could foresee what reality would throw into the mix except those close to spaceflight. I was close to it as a 17 year old hobbyist in 1973 and knew that the post Apollo public mentality was basically dooming human spaceflight unless some kind of economical solution was found to human access to space. I knew the basics of rocketry but only people working there at the time would know if shuttle was really viable. Indeed a few suggested from the start that it wasn't an economic solution.<br /><br />docm:<br />The drop tests done by Scaled Composites show that.<br /><br />Me:<br />Shuttle was drop tested as a 1/5th scale model back in 1970 from a helicopter. And full scale dropped from 747s in the ALT flights. Drop tests validates the hardware and its operational capabilities, not its economical ones.<br /><br />docm:<br />If it were a car it would be the Edsel.<br /><br />Me:<br /> A good analogy. Its also one that illustrates that its not always the idea that causes problems. Its how the idea is realized in actual construction and operation. I often invoke the DC-3 aircraft. The Douglas DC-3...the workhorse of aviation in aviations early days. How many people know about the DC-2. The DC-2 was the not nearly as successful DC-3 predecessor. But it was used to apply lessons learned to the DC-3. I <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[josh_simonson]

>Spaceflight is an inherantly dangerous business as long as chemical rockets are used. <br /><br />This is not true. Rather, spaceflight will be an inherently dangerous buisness as long as the technologies involved push material science to it's limits with low design margins.<br /><br />Chemical rockets, mostly military, fly on a daily basis with extremely high safety and reliabiliy. The difference between a starstreak and an atlas is the starstreak has a design margin />2, as opposed to <1.4.<br /><br />The only ways to increase margins are either breakthroughs in material science like CNT composites, or building bigger rockets and trading performance for reliability.<br /><br />Non-technical people see that airplanes are highly reliable, then conclude that spaceplanes should be capable of the same level of reliability. This is completely and utterly false because the safety margin of an airplanes parts cannot be extended to spaceplanes.<br /><br />Look at why the two shuttles were lost. Both were failures of materials that had to operate in very extreme environments. The seals on the SRB have to hold together when very hot, and simply could not work below 0'C. Similarly the foam on the shuttle has to hold together at extreme cold temperatures in a rough environment, and it simply can't be made to hold together with high reliability.<br /><br />The only way a spaceplane could be made as safe as a modern airplane is if material science allows us to build spaceplanes with the same margins that are used in modern aircraft. Holding out for that day is a bad bet because it may never happen.

 

[qso1]

Your is a very broad, but valid comparison.<br /><br />I would say however, that another reason military rockets such as the Starstreak are more reliable is twofold. The bigger the rocket, the more complex it is. The other reason, many more are manufactured leading to a tremendous amount of learning curve experience. At best, expendable Atlas sized rockets and above may fly twice a month. The Saturn-Vs best rates were once every two months and shuttles best was Discovery from its first flight in 1984 to the August 1985 sixth flight, or same as Saturn-V. This is partly due to limited launch facilities but also due to the complex processing required to assure safe flight.<br /><br />josh_simonson:<br />The only ways to increase margins are either breakthroughs in material science like CNT composites, or building bigger rockets and trading performance for reliability.<br /><br />Me:<br />Agreed.<br /><br />josh_simonson:<br />Non-technical people see that airplanes are highly reliable, then conclude that spaceplanes should be capable of the same level of reliability. This is completely and utterly false because the safety margin of an airplanes parts cannot be extended to spaceplanes.<br /><br />Me:<br />Agreed here as well. Me being a technical person, and being familiar though not an expert, on rockets. I knew even as a teenager the shuttle would not operate like an airplane. I used the term airliner ops to convey the idea thet the shuttle would be more like an airliner than a rocket.<br /><br />josh-simonson:<br />Look at why the two shuttles were lost. Both were failures of materials that had to operate in very extreme environments. The seals on the SRB have to hold together when very hot, and simply could not work below 0'C. Similarly the foam on the shuttle has to hold together at extreme cold temperatures in a rough environment, and it simply can't be made to hold together with high reliability. <br /><br />Me:<br />Agree here as well. I would only add that the shuttle accidents re <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[willpittenger]

About six months ago I suggested a very futuristic spaceplane that would take off and land on runways. At no point would it behave like a conventional "rocket". It had several key advantages that no capsule would ever have. Please realize that this concept presumably would take another 50-75 years to build for real.<br /><br />* Self-Ferrying capability -- Actually, it was too big (grossing fully loaded and fueled enough to set a record) to ferry around. I also did not like the concept of attempting to dock in the air with a booster or requiring Mate/Demate devices all over the place like we have with STS. Therefore, I specified that a series of Take Off Jets (or TOJ) would provide subsonic travel.<br /><br />* Pick the load up wherever -- The concept was that you do not need to ship your satelitte to my base. Rather, like UPS, I would come and get it. Companies like Lockheed might even offer special "launch" prices that include orbital insertation.<br /><br />* Any LEO orbit you want -- Because I would be able to fly for a while before going for orbital insertion, I could get under the exact orbit you want and make the manuever there. I would not need to make any inclination changes one up. Altitude? Maybe. But not inclination.<br /><br />* As a bonus, EVERY spaceplane has a lot of bring back capability. Their length accomodates stuff that a capsule could not. Someone left a booster up there you want to retreive? No problem. As long as it fits, guess what... That object comes back. <div class="Discussion_UserSignature"> <hr style="margin-top:0.5em;margin-bottom:0.5em" />Will Pittenger<hr style="margin-top:0.5em;margin-bottom:0.5em" />Add this user box to your Wikipedia User Page to show your support for the SDC forums: <div style="margin-left:1em">{{User:Will Pittenger/User Boxes/Space.com Account}}</div> </div>

 

[j05h]

> As a bonus, EVERY spaceplane has a lot of bring back capability. Their length accomodates stuff that a capsule could not. Someone left a booster up there you want to retreive? No problem. As long as it fits, guess what... That object comes back.<br /><br />This is a lot further along than what we have today. The same argument can be applied to large "capsules" like LEO (Boeing) and ROMBUS (Bono). Imagine a reusable dropship on top of Sea Dragon. You start talking about cargo capacity that rivals a small ship and standardizing huge cargo holds and handling makes sense. Where your spaceplane might have space for 2 containers, a LEO would have space and upmass for nearly a dozen. <br /><br />My absolute favorite idea for the ground segment of truly industrial space is to land and launch boosters off the coasts, and process them at sea. With extremely large boosters, this solves sonic boom and handling issues. The craft fit right into standard international shipping by storing cargo in cargo containers. These craft are based at a commercial version of a Joint Mobile Offshore Base (JMOB), which provides propellant storage, payload processing, servicing and loading. This solution lends toward industrial propellants like propane or natural gas - the tanker pulls up to the JMOB, pumps it to the waiting craft. The JMOB platform is envisioned as being part of a larger complex that includes container scanners, fish processing and other activities. Ferries, robot cargo barges and VTOL aircraft support the offshore city and spacecraft. Extremely large spacecraft can be serviced directly afloat or drydocked. Locations could include the Gulf of Mexico or off any large metropolis. <br /><br />If the starting assumption is "fit in" to the economy, as weird as this architecture is, it makes perfect sense. Big craft of any kind will have large downmass.<br /><br />This is the article that originally turned me onto the floating base thing:<br /><br />http://www.tec</safety_wrapper <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>