Mankind needs an inexpensive method of launching spacecraft. For the past 40 years, the only method has been multi-stage expendable rockets. There has always been great interest in a single-stage Reusable Launched Vehicle (RLV), to allow ordinary people to visit outer space for the same cost as a trip to Europe. In fact, today’s “Space Shuttle” was envisioned as a single-stage RLV, but that proved impractical so two semi-reusable rocket boosters and massive disposable fuel tank are needed, which pushes the total cost for each mission over $500 million. As a result, hopes for 100 shuttle launches a year have dwindled to four a year. NASA canceled a more recent attempt at a single-stage RLV, the X-33/Venturestar, when problems proved insurmountable. <br /><br />http://www.skyramp.org<br /><br />All efforts at any space effort of scale, will fail unless Assisted Space Launch Systems are designed, developed, and become fully operational.<br /><br />The Bush Moon, Mars, and Beyond Program is doomed to fail, with out the development and use of Assisted Space Launch Systems!<br /><br />Expendable Launch Vehicles are a terrible waste of materials, money, and manpower, and will never be able to support any truly large and prolonged space effort of scale!<br />
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This is a form of assisted launch from the 1952 movie "When Worlds Collide"<br /><br />This Vision lives today in the International Space Plane (ISP) Program.<br /><br />http://www.international-spaceplane-program.org<br /><br />
Maglev launchers would be feasible only on the moon, where there's no atmospheric drag and the escape velocity is much lower than on Earth.Only payloads would be propelled, maybe with a small rocket engine for maneuvering and orbit insertion.<br />On Earth, only a small portion of the escape velocity could be achieved with a device like u proposed. This means a heavy payload (including a big rocket engine) would be launched , all against atmospheric drag. All this makes it a rather cumbersone, inefficient method.<br /><br /><br /> <div class="Discussion_UserSignature"> <p>http://asteroid-invasion.blogspot.com</p><p>http://www.solvengineer.com/asteroid-invasion.html </p><p> </p> </div>
Not True!<br /><br />The Assisted Launch System is not used to provide total launch energy!<br /><br />The Assisted Launch System (ALS) acts as the First Stage of the Launch Cycle! <br /><br />The ASL is reused MANY times (No Materials or Resources Wasted!), and the RLV or SSTO Space Plane does not carry the Extra Structure or Fuel Mass as part of the Launch Vehicle.
spacefire, this is a good example of this for you.<br /><br />********************************************<br /><br />grooble: "Have you ever seen the launch platforms on aircraft carriers that catapult the jet? There needs to be a spacecraft version." <br /><br />grooble, <br /><br />Firstly, YES!, i have seen the launch platforms on aircraft carriers that catapult the jets! As i was in U.S. NAVAL Aviation, and was able to be up close and personal with this technology, and operations. <br /><br />Secondly, your comment that there needs to be a spacecraft version, needs to be a little more specific! <br /><br />Do you mean, as actually in Orbit or in Space that a Larger Mother Ship would launch Smaller Ships in this manner? <br /><br />If So! This would have problems in reality, in a Zero Gravity or Micro Gravity Environment. Any catapult system on a Larger Mother Ship would create a recoil in the amount of the force of the ejected mass, Smaller Ship, which would push the bigger ship in the opposite direction, and would thus require thrust (ie:fuel) to counter this, and therefore would make such a catapult system on an Orbital or Space Based Facility or Ship, impractical and creating more problems than solving, and nothing would be gained or saved from this approach in the end! When large Facilities and Ships are built in the coming days, in Earth Orbit and in Space, any smaller craft or ships that are launched, would do so under their own power, and separate from the larger launch platform, whether that is a Station or Ship! <br /><br />If you mean a Catapult Like System in a Gravity Well, like on a Planet, Moon, or Very Large Body in Space (ie:I say very Large Body as a Smaller Body even a small asteroid would be effected by launch recoil forces, and such an approach has even been suggested as a thrust component to move small asteroids, but this is another thread altogether!) this would work, and would have many benefits to Launch System Capabilities and Launch Vehicle Fuel &
The current launch rates are too low for the recoperation of the investment into an assisted launch system. It might be more worth while to reduce launch costs via conventional methods first , like spaceX is trying to do. Once there is an increases launch rate it might be easier to get the investment needed for such a scheme.
nacnud: "The current launch rates are too low for the recuperation of the investment into an assisted launch system. It might be more worth while to reduce launch costs via conventional methods first , like spaceX is trying to do. Once there is an increases launch rate it might be easier to get the investment needed for such a scheme."<br /><br />nacnud,<br /><br />You have it %$# back wards!<br /><br />It is "NOT" the SOLUTION which will be fixed by the PROBLEM!!!!<br /><br />It "IS" the PROBLEM which will be fixed by the SOLUTION!<br /><br />It "IS" the creation of the ADVANCED GROUND BASED ASSISTED LAUNCH SYSYTEM, which will make Feasible, Economic, and Routine Space Launches of ANY SCALE, possible!<br /><br />Think of the thousands of Space Launches since SPUTNIK and in each case we threw away 85% to 90% of the Launch Vehicles and Space Craft in the Fires Of Reentry!<br /><br />This all added up, is TRILLIONS+?!? of Dollars, and MANY MILLIONS+?!? of "TONS" of Precious High Grade Ores, Billions +?!? of Man Hours and Precision Machining and Construction & Assembly Man Hours, Much Loss Of Life!<br /><br />50 some odd years!<br /><br />What Does Humanity Have To Show For It!!!!!?????<br /><br />Not A &^% Darn Thing! That’s What!!!!!<br /><br />No Big Space Stations!<br /><br />No Luna Bases!<br /><br />No Mars Bases!<br /><br />No Manned Interplanetary Space Craft!<br /><br />Ever since the Founders of Modern Space Efforts died and passed away! Humanities Space Efforts & Programs have been Strangled To Death By Military Powers Seeking Control At Any & All Costs, Stuffy Nosed Academics Trying To Get Advanced & Sell Books, and Political Idiots Bent On A Politically Correct Leftist Agenda!<br /><br />When Wernher von Braun was alive and in control!<br /><br />We were only a hairs distance from the goal, which was a full scale all out dedication and support of RLV/SSTO/ALS technology and capability!<br /><br />Then Kennedy was Assassinated!; NASA was taken over by the Military &
nacnud, this is what "JUST ONE" Space Shuttle Main Tank represented in the form of Usable Structure & Space!!!!!!<br /><br />We Have Pissed Away Over 108+ Of These Structures!!!<br /><br />This "MUST BE STOPPED!!!"<br /><br />
I think you might have got the wronge end of the stick there.<br /><br />Basically there may be better ways of spending the money needed to produce an assisted launch facility rather than on an assisted launch facility<br /><br />There is nothing wrong with the concept, it’s just expensive. It will produce savings but might require a lot of launches. It would need a lot of investment in a single project, I would prefer to invest in many smaller projects and make sure one gets finished. I'm fed up of the string of half finished vehicles left behind by the changing fashions at NASA.<br /><br />Personally I would like to see a lot of small launches of reusable or semi reusable rockects first. Basic, simple rockets. Similar to what Space Dev, Scaled, SpaceX etc are developing. If you took all the investment in those projects it still might not be enough for an assisted launch facility.<br /><br />I want the same thing as you, cheap access to space, but I don't think we should put all our eggs one basket.
nacnud, So!? On that premise!<br /><br />We want to provide a river crossing, we build many small bridges each with very limiting capabilities, and after the first vehicle crosses the bridge, we blow it up!; and build another bridge! :-( Hmmmm! Interesting Philosophy, Indeed!<br /><br />This instead of building a brooklyn bridge, which will allow many millions of cars to cross the river! It will be expensive and will take a few years to build! But when done will be a great achievement, and tremendous resource and asset!<br /><br />Instead of building an interstate highway system able to speed millions of vehicles and massive resources to untold number of destinations!<br /><br />So, instead!, we build a whole bunch of dirt roads all going nowhere, and not able to support anything other than horse & buggies! :-( Hmmmmm! Interesting Philosophy, Indeed!<br />
If your going to do the analogy thing look at the channel tunnel, a marvel of engineering, a wonder of our age, and currently almost bankrupt because it can't compete with the ferries.<br /><br />Sorry but I don't like bun fights, bye.<br /><br />
henryhallam: "Please stop capitalizing every word of your sentences, it makes them harder to read."<br /><br />henryhallam, Point Taken! 
Was just making a stern point by doing this! I would not want a few capital letters to detract from the more important content!<br />
Was just making a stern point by doing this! I would not want a few capital letters to detract from the more important content!<br />nacnud: "If your going to do the analogy thing look at the channel tunnel, a marvel of engineering, a wonder of our age, and currently almost bankrupt because it can't compete with the ferries."<br /><br />nacnud,<br /><br />Your analogy would have been 100% correct if you had compared the Chunnel to a Sailing Ship! But, as you have presented it, it is not a good analogy or comparison in regards to my analogies, or the present problem and issue in regards to "Human Space Launch Capability, Resources, and Philosophy!"<br /><br />You analogy is an Apples & Bananas comparison! Not even close!<br />
Thanks <img src="/images/icons/smile.gif" /><br />These ideas do look interesting, but I find it hard to believe such a system could replace the first stage of a launch vehicle. Certainly the size and payload of the first stage could be reduced though.<br />If I remember correctly, on most launches the first stage separation occurs at a velocity of 2.5 to 3km/s and an altitude of around 60-70km. Since the launch assist occurs at ground level, the velocity on leaving the ramp would have to be higher, perhaps 3.5 or 4km/s or a little more. Now there are two problems:<br /><br />(1) This velocity corresponds to mach 10 to 12. This is in the lower atmosphere where the air is very dense. Heating loads on the spacecraft will be enormous, I would say very likely much more than during a normal re-entry (since in a re-entry most of the deceleration is done at an altitude of 50km or so). Aside from the heating issue, the vehicle will experience significant deceleration and you will lose a lot of the energy you just supplied with the ramp.<br /><br />(2) You have to accelerate to 3.5-4 km/s (or more to cover aerodynamic losses) while on the ramp. The ramp length is given by s=v^2/(2a). If you assume a generous maximum acceleration for humans of 5g or 49m/s^2, the ramp must be 125km long for 3.5km/s or 163km long for 4km/s. This is quite the engineering feat! Rockets carrying cargo don't have such a problem, but even if you allow an acceleration of 15g (I think much more than that would be pushing the limits of the spacecraft structure) the ramp lengths are still a third as long.<br /><br />I think in all honesty that the resources necessary for such a project would be better spent making first stage boosters either much cheaper, more reusable, or both. I think the running costs of a ramp assist system would end up being more than the cost of recovery, refurbishment and reuse of a well-designed first stage rocket engine.
henryhallam,<br /><br />You are stuck in the expendable launch mode rut and thinking!<br /><br />Lets take the shuttle for example!<br /><br />Nearly half its fuel, and designed structure, mass, is used to boost the shuttle to around ~1000 mph!<br />http://www.skyramp.org<br /><br />With Assisted Launch System (ALS), using a Mountain Site on the Earths Equator, like maybe in Brazil.<br /><br />The ALS would use a launch gradient of around 45 degrees, and would release the Launch Vehicle & Launch Sled at between 1000 mph and 2000 mph at the highest altitude able too. (ie: using the highest usable mountain site available)<br /><br />If you were to plug, lets say Venture Star like RLV in to this situation, the vehicle already designed would be more than enough to have Orbital Insertion Capability.<br /><br />If you factor in, lets say like, a reusable winged second stage, or aerobic thrust designed into the RLV to take advantage of atmospheric O2 as long as possible (reducing the need for onboard liquid 02 and related structure-ie:Mass)<br /><br />This can be done!<br /><br />And must be done!<br /><br />People, Scientists, and Engineers are stuck in an Expendable Launch Vehicle mode of thinking and philosophy!<br /><br />An Advanced Assisted Launch System (ALS) will work!<br /><br />Believe me, as the ISA Organization has studied this for nearly 10 years now, and in every study, this has risen to the forefront as the best way to pursue, and to attain, true orbital access of scale in any meaningful or useful way!<br /><br />It will also eliminate Billions in unneeded waste, and the needless destruction of precious high-grade metal ores and highly machined structures and parts in a fiery end.<br /><br />ASL can & will solve this!<br />
Unconvincing. You will need to persuade me with numbers and engineering facts, not baseless rhetoric.<br /><br />There is a variable called dynamic pressure which is very important an aerodynamics. This is what determines such things as the deceleration due to drag, heating effects on the thermal protection system, and load on the structure of the spacecraft.<br /><br /><font color="yellow"><br />Nearly half its fuel, and designed structure, mass, is used to boost the shuttle to around ~2000 mph!<br /></font><br />The Space Shuttle contains approx. 1727 tonnes of propellant in the external tank and SRBs. When half of this has been used, the velocity is around 2650mph, not 2000. The altitude is 24km, where the air is thin at 2.9% of sea level pressure, and aerodynamic pressures aren't much of a problem. Using the Orbiter simulator I determined the dynamic pressure to be approx. 24 kPa, the true value will not be exactly this but that doesn't matter for purposes of this discussion. It is a good ballpark figure.<br />During the hottest part of re-entry, the dynamic pressure is around 60kPa or a little less (again, using the Orbiter simulator).<br /><br />The highest mountain in Brazil is Pico da Neblina at 3.0km.<br />The air pressure (static) at this altitude is 70% that at sea level.<br /><br />Dynamic pressure is directly proportional to the static atmospheric pressure (and also proportional to the square of the velocity).<br /><br />If you were to have the same velocity at that altitude (and note that because the altitude is lower, you would in fact need MORE velocity to have the same energy) the dynamic pressure would be (70 / 2.9) = 24 times as great. Using the numbers from Orbiter, that gives Q = 580kPa. This is nearly ten times as much as during the hottest part of re-entry! I doubt that anything but a very thick ablative coating could withstand the heating load. The structural load would also be incredible and would require a much stronger structure if t
henryhallam: "Unconvincing. You will need to persuade me with numbers and engineering facts, not baseless rhetoric."<br /><br />henryhallam,<br /><br />I have contacted a few aerospace scientists, and the two leading scientists in the International Space Agency - International Space Plane Program -and- International Advanced Assisted Launch Program.<br /><br />I will have your stifling and overwhelming numbers & engineering facts, as soon as I get a reply from those I consult on such matters!<br /><br />My rhetoric you make reference too; I have been assured by very competent authorities on this matter, that all I say is backed up by good science, and good engineering principles!<br /><br />Not all can be shared, as some info is indeed classified!<br /><br />But I will share what I can, in the numbers and engineering facts, as you say!<br /><br />Could be a couple of days though!<br /><br /><br />
henryhallam: "The highest mountain in Brazil is Pico da Neblina at 3.0km."<br /><br />henryhallam,<br /><br />Mt. Chimborazo, located 150 km southwest of Quito, is Ecuador's highest mountain (6310 m - 20,700 ft) and has the distinction of being the point on the earth's surface which is farthest from its center - due to the earth's equatorial bulge.<br /><br />This is another prime location for the ISP/ASL system to be located! I only mentioned Brazil, because it is a stable country and government, and is part of the International Space Station program.
<font color="yellow">"the marginal costs of building each vehicle itself are a lesser factor (and would not be significantly reduced by making the first stage smaller), and the propellant is a tiny footnote on the budget."</font><br /><br />When launch vehicles have at least the first stage reusable (hopefully starting from Falcon I) your point gets even stronger. After that it will be really difficult to justify building multi-billion dollar fixed ramp to save a few drops of propellant. It wont save any energy anyway. Millions tons of concrete, thoudands of tons of steel, copper and whatnot don't come free. And propelling the sledge requires energy that must come from something, a powerplant is needed. Sum it up and maybe millionth launch would be break even, compared to conventional booster with reusable first stage, but just <i>maybe</i>.<br /><br />And a beautiful mountain would be ruined for ever. Imagine what 180dB roaring would do to those glaciers and steep snowy slopes <img src="/images/icons/frown.gif" /><br /><br />I calculated that a shuttle could handle 390m/s (~870mph) at 6000m, assuming 50kPa maximum dynamic pressure. If megalomaniac technical effort is a must then people should go after high-altitude supersonic 'White Knight', a XB-70 Valkyrie derivative. For example mach 2 at 24,000m would do a lot more good than ramp at 6000m, having much less technical hurdles and much more options.
>Mankind needs an inexpensive method of launching spacecraft.<<br /><br />I agree with this statement. There is one proven alternative to the rocket booster fisrt stage, and that is using planes. Proven by X-15 and SpaceShipOne. Its cheap, safe, and the infrastructure and experts already exists. Launch the second stage from a plane at altitude. This works.<br /> <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>
henryhallam: ">Unconvincing. You will need to persuade me with numbers and engineering facts, not baseless rhetoric.<"<br />henryhallam: " />Using the numbers from Orbiter, that gives Q = 580kPa.<"<br /><br />henryhallam, this is a reply to your post, from the Initernational Space Agency, Chief Program Officer for the International Advanced Assisted Launch System (ASL) Program. Please see Dr. David Maker reply below! http://www.skyramp.org<br />http://www.international-space-agency.net/david_maker_biography.html<br />http://www.international-spaceplane-program.org<br /><br />*************************************************************<br /><br />This is nearly ten times as much as during the hottest part, of re-entry! I doubt that...<br /><br />There appears to be a misunderstanding here. At first your critic seems to believe you are advocating getting the RLV up to orbital velocity on the track itself. It would take a 1000km long track to do this at 3g acceleration and the RLV would burn up like a meteor anyway on leaving the track, so this all sounds absurd to him, which it is. But you are advocating approximately mach 1 1aunch. He is confusing your scheme with rail guns. <br /><br />But the X-33 was close to orbiting anyway. Perhaps replacing those heavy aerospike engines with titanII s and putting it on a track and it would have orbited and with payload especially given that the problems with those carbon fiber fuel tanks have recently been solved, making for an even better mass ratio. We need an integrated impulse equation calculation to show this for sure with the isps, deadweight, fuel capacity included. In any case one thing it does show is that a far greater gain can be gotten from mach 1 or mach 2 assisted launch velocity than you would have oth
holmec: ">I agree with this statement. There is one proven alternative to the rocket booster fisrt stage, and that is using planes. Proven by X-15 and SpaceShipOne. Its cheap, safe, and the infrastructure and experts already exists. Launch the second stage from a plane at altitude. This works. <"<br /><br />holmec, The International Space Plane (ISP) Program, is also keeping this option open! But this is another thread all together!<br />
lol north_star, are you forgetting that neither spaceship one or the X-15 never went into orbit?<br /><br />What you SHOULD be reffering to is the Pegasus, which launches rather small amounts of cargo and costs $20-30million per launch.<br /><br />There is another launch vehicle though by AirLaunch LLC being developed for the FALCON program for the USAF that promies to launch around 900kg into orbit for $5million.
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