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Thread: What is the next/best alternative to current rockets?

  1. #1 What is the next/best alternative to current rockets? 
    Forum Cosmic Wizard icewendigo's Avatar
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    I was wondering what alternatives for reaching orbit to the chemical reaction rockets are there which alternate tech is likely to exist first as a preferable alternative?


    Are nuclear-something propulsion rockets likely to be used before any space elevator ever gets built?


    Can carbon nano fibers be used to create a vacuum baloon ship with light beams to it so that it could reach near-orbit?


    Are ramjet-ish super fast space planes likely to be operational before other solutions?


    Is it possible to have a solar powered automated coastal based installation, that is automated to transform sea water into rocket fuel, and refills space planes that land on a nearby airstrip?


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  3. #2  
    Forum Freshman John L's Avatar
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    How about using carbon nanotubes for creating a space elevator? Of course they will have to be mass produced first.


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  4. #3  
    Forum Bachelors Degree 15uliane's Avatar
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    Nuclear rockets will never get off the ground (figure of speech) in atmospheric use; there are just too many hoops to jump through put forward by governments.
    NERVA - Wikipedia, the free encyclopedia
    Nuclear propulsion - Wikipedia, the free encyclopedia

    I think it will be spaceplanes, they are efficient, easy to use, safer than chemical rockets and more familiar to the average consumer. We are not very far off today, although NASA has really dropped the ball when it comes to manned spaceflight.

    Is it possible to have a solar powered automated coastal based installation, that is automated to transform sea water into rocket fuel, and refills space planes that land on a nearby airstrip?
    Of course.
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  5. #4  
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    SKYLON: A Single Stage to Orbit (SSTO) spaceplane, currently under development by a british company. It is single stage to orbit and that's why it is awesome; meaning it won't need replacing (only need re-fueling and maintenance).

    The technology it use is:
    1. it use a special jet engine that can operate up to Mach 5.5 (which isn't a scram jet), but which can also operate in rocket mode,
    2. and also employ a low pressure fuel tank (which mean: safety) and also has a total size that is significantly bigger than the US Space Shuttle: so its re-entry speed is much slower and cooler than the space-shuttle (thus don't need fragile heat shield)
    3. and its hull is made of carbon fibre composite
    4. it fly like an airplane...

    http://en.wikipedia.org/wiki/Skylon_(spacecraft) ;Skylon wiki
    Skylon spaceplane | British invention is out of this world - YouTube ;Skylon video
    Last edited by msafwan; December 9th, 2011 at 04:14 AM.
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  6. #5  
    Forum Cosmic Wizard icewendigo's Avatar
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    Skylon sounds great.

    Off the wall idea:

    Could carbon nanotube be used to create a giant vacuum filled saucer shaped balloon (ex:several times the size of a sports stadium) with a hole in the middle and raise a rocket payload high in the atmosphere where launch would take place? And could there be vertical cylinders in the airship taking air from the top and pushing it downwards with electric turbines, while on the ground powerful microwave beams could transfer electric energy from the ground based electric grid to the airship lifting the rocket to high altitude(whatever that is)? Once the airship launch platform reaches as high as it can with a rocket payload the launch is initiated? Maybe the giant balloon can be covered by a photo-voltaic paint that channels solar energy to the turbines pushing it up?

    What would be the guestimate size of an airship required to lift a orbital rocket with a 10 ton payload? Would the rocket require much less fuel to reach orbit if it starts from an altitude reachable by a giant airship?
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  7. #6  
    Universal Mind John Galt's Avatar
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    How about a really big trampoline?
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  8. #7  
    Forum Cosmic Wizard icewendigo's Avatar
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    How about a really big trampoline?
    LOL, ouch, that bad eh. Oh well.
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  9. #8  
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    Skylon looks good, agreed, but recall if you will that the SR-71 aerospacecraft leaked like a sieve, by design, as thermal expansion at altitude made this necessary. quite a lot of liquid hydrogen could escape from Skylon by same means, compromising performance. There is reason multiple stage spacecraft are the rule rather than exception today, chemical reactions are puny, puny, puny, so other technologies can and must inevitably be developed.

    http://en.wikipedia.org/wiki/StarTram

    http://nextbigfuture.com/2007/07/gaseous-core-nuclear-design-liberty.html
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  10. #9  
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    Quote Originally Posted by icewendigo View Post
    How about a really big trampoline?
    LOL, ouch, that bad eh. Oh well.
    Do not feel bad, Prince has seen serious proposal on Internet to scale up medieval trebuchet to launch orbital payloads. Is good to brainstorm like this, nice thread.

    Trebuchet - Wikipedia, the free encyclopedia
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    For inexpensive transport of large tonnages of people and goods into orbit, nothing would beat the space elevator concept.
    Space elevator - Wikipedia, the free encyclopedia

    It would have to be very long, since geostationary orbit is about 42,000 kms from ground, and the cable would be nearly twice that. In addition, it would have to be wide enough - a ribbon rather than a cable - so that space junk putting holes in it will not make it fail. It would cost an incredible amount of money. However, once in place, transporting goods to orbit would cost cents per kilogram, rather than thousands of dollars.

    Needless to say, we are still a long way off having the technology.
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    In one of the books I am working on, I have launch vehicles that use scramjets based around ALICE motors.
    ALICE rocket motors burn aluminum powder mixed with water ice, to generate large amounts of hot hydrogen.
    In the book, this is fired into the combustion chamber of a scramjet, to be burnt in the airflow.
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  13. #12  
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    Quote Originally Posted by skeptic View Post
    For inexpensive transport of large tonnages of people and goods into orbit, nothing would beat the space elevator concept.
    Space elevator - Wikipedia, the free encyclopedia

    It would have to be very long, since geostationary orbit is about 42,000 kms from ground, and the cable would be nearly twice that. In addition, it would have to be wide enough - a ribbon rather than a cable - so that space junk putting holes in it will not make it fail. It would cost an incredible amount of money. However, once in place, transporting goods to orbit would cost cents per kilogram, rather than thousands of dollars.

    Needless to say, we are still a long way off having the technology.
    Maybe not so much as you are thinking, people said same thing about Moon landings in fifties. If sufficient incentive exists, will be built, inevitably.
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    Quote Originally Posted by PetTastic View Post
    In one of the books I am working on, I have launch vehicles that use scramjets based around ALICE motors.
    ALICE rocket motors burn aluminum powder mixed with water ice, to generate large amounts of hot hydrogen.
    In the book, this is fired into the combustion chamber of a scramjet, to be burnt in the airflow.
    Is solid fuel rocket using water as oxidizer. With hydrogen gas escaping for higher specific impulse, this could be burnt with atmospheric oxygen as you suggest. Most interesting, thank you for bringing to Prince's attention. Still, being chemical rather than nuclear, a loser in the long run.
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  15. #14  
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    What is needed is a way to keep the heavy fuel on the ground and just launch the payload. The payload just needs reach orbital velocity. Maybe some type of steam catapult or rail gun. The delta V would be very high over the length of the launch acceleration, so probably not safe for humans but a good bet for launching cargo.
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    Quote Originally Posted by Sealeaf View Post
    What is needed is a way to keep the heavy fuel on the ground and just launch the payload. The payload just needs reach orbital velocity. Maybe some type of steam catapult or rail gun. The delta V would be very high over the length of the launch acceleration, so probably not safe for humans but a good bet for launching cargo.
    Maglev...

    StarTram - Wikipedia, the free encyclopedia
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  17. #16  
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    Quote Originally Posted by Sealeaf View Post
    What is needed is a way to keep the heavy fuel on the ground and just launch the payload. The payload just needs reach orbital velocity. Maybe some type of steam catapult or rail gun. The delta V would be very high over the length of the launch acceleration, so probably not safe for humans but a good bet for launching cargo.
    And sure to incinerate the cargo if launched to orbit from the earth's surface.
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  18. #17  
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    Quote Originally Posted by MeteorWayne View Post
    Quote Originally Posted by Sealeaf View Post
    What is needed is a way to keep the heavy fuel on the ground and just launch the payload. The payload just needs reach orbital velocity. Maybe some type of steam catapult or rail gun. The delta V would be very high over the length of the launch acceleration, so probably not safe for humans but a good bet for launching cargo.
    And sure to incinerate the cargo if launched to orbit from the earth's surface.
    explain please?

    If acceleration phase is perhaps 1-3 kilometers could not current materials take the atmospheic friction? Say a long track up the side of a mountain?
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  19. #18  
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    Escape velocity is 11.2 kilometres per second. This does not change if you make the acceleration phase longer. That speed is enough to incinerate anything small, and drastically heat anything large. If you had a large projectile, well protected with ceramic coverings or an ablative shield, you could get most of it into orbit.

    It is, of course, impossible to transport anything living or delicate that way, since the G forces would be extraordinary. It might be a useful method of firing some supplies into orbit, though. We do not yet have this technology, and it would cost megabillions if not trillions to set it up.
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  20. #19  
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    I'm trying to figure the delta v over a 3kilometer launch rail but I can't remember the math. from V=0 K/s to v=11.2 K/s over a distance of D= 3K
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  21. #20  
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    huh? delta V is 11.2 km/s in the direction of the rail. That can't be what you meant.
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  22. #21  
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    SPACE CANNON: a very very large cannon that launch projectile into orbital trajectory.

    There no stopping to the idea of using cannon to send object into space, except the size of the cannon itself. The cannon MUST be big to circumvent the physical limit of gas compression; a very very high compression (such as for launching projectile into space) will cause conventional cannon to fail because the gas started to behave like a liquid, therefore by simply prolonging the lenght of the barrel: the projectile can achieve the required delta-v with a lower gas pressure and longer acceleration distance. The result is: SPACE CANNON (alternatively: Rail-gun) which could launch projectile at very very very high speed (higher than speed of sound, eg: > mach 5).

    Space gun - Wikipedia, the free encyclopedia :Space Gun (wikipedia)
    Cannons to the Planets - YouTube :Quicklaunch, Inc (GoogleTalk on Space Gun concept)
    http://media.defenseindustrydaily.co..._CONOPS_lg.jpg :US NAVY Railgun on sub-orbital trajectory
    Last edited by msafwan; December 9th, 2011 at 04:16 AM.
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  23. #22  
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    Did you actually read the Wiki article you linked to? Like a 60 km gun barrel? The need to perform an orbital maneuver to circularize the orbit?
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  24. #23  
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    Quote Originally Posted by MeteorWayne View Post
    Did you actually read the Wiki article you linked to? Like a 60 km gun barrel? The need to perform an orbital maneuver to circularize the orbit?
    That is not a problem; you can attach rockets to the payload, and conventional electronic chips are already high g-tolerant. And it isn't 60Km long: it is just 1 Km long (Quicklaunch's cannon).

    Honestly the Wiki is just a quick reference, I actually find out about this concept from the GoogleTalk.
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