Banner
    Space Launch Mass Drivers And Von Neumann Machines: Science Meets Science Fiction
    By David Brin | March 21st 2012 11:20 AM | 6 comments | Print | E-mail | Track Comments
    About David

    David Brin is a scientist, public speaker, technical consultant and author of books including The Postman, Startide Rising, The Uplift War and Existence...

    View David's Profile



    The notion of gun-propelled launch goes back to Jules Verne. Such Mass Drivers have been envisioned in numerous Sci Fi tales, including "Earthlight", by Arthur C. Clarke, Robert A. Heinlein's "The Moon is a Harsh Mistress" and "Heart of the Comet" by Benford&Brin. We've also seen them portrayed in Buck Rogers, Babylon 5 and Halo. 

    Now, two researchers propose that a space-capable mass driver may be feasible. Startram would act as an electromagnetic catapult, using maglev technology, to accelerate and launch spacecraft into orbit, without using rockets or propellant. James Powell and George Maise take a highly optimistic view, claiming that a system capable of launching payload into orbit for less than $40/kg could be built using existing technology—if we were to gather substantial international support.

    Sloping a launcher along the western face of Mt. Chimborazo in Ecuador or Mt. Kenya would allow a very profitable/cheap launch system for cargo. But see the concept for a 1200 km long version (to spread out the g-load) for passengers! And yes, we studied stuff like this long ago, back when I worked at CalSpace.

    A slanted mass drive along Chimborazo (and yes it needs to be near the equator) would need "super-capacitor" surge capability, far exceeding the ability of nuclear plants to deliver in real time. But here's how you do it:

    You have several nuclear power plants--but their main job is to raise/pump water to several big/high artificial lakes. When you fire, you DRAIN those lakes through many-many-many rapid tubes to standard hydro-power turbines. The nukes are just for steady replenishment of the lakes.

    This is highly do-able with existing tech. Especially if you have whirling tether grabbers awaiting in low earth orbit. These could snag the cargoes and give them circularization momentum... or else act as electrodynamic tugs from there.  (To learn the principles involved, see my short story Tank Farm Dynamo.)

    Hence, the cargoes might not even have to take along the fuel to circularize and the tethers themselves use solar power to replenish the donated momentum. Again, there's nothing to research... just develop. We could be doing it within 5-10 years.

    ==Autofacs and von Neumann Machines==



    Philip K. Dick’s 1955 post-apocalyptic story, Autofac, short for Automatic Factories, was one of the earliest fictional portrayals of nanotechnology and self-replicating machines – an example of von Neumann probes, which he called “Universal Assemblers.” Carl Sagan and Freeman Dyson both argued that the reason we have observed no self-reproducing probes in the universe is because the probes would spread like a cancer; building such probes would be suicidal to their creators and destructive to any species they encounter.

    Indeed, Dick’s Autofac is set after war has devastated much of Earth; robotic autofacs scavenge and monopolize the planet’s remaining resources (“We mere people come second.”), to build devices that humans no longer need. Humans have lost the ability to communicate with or control the autofacs, as they continue their relentless autonomous activity: “Maybe some of them are geared to escape velocity. That would be neat – autofac networks throughout the universe.” Would it really? My next novel, Existence, will offer a new take on some of these probes…

    ==Terminator Goggles==


    Augmented Reality is soon to arrive: Google Goggles are smart glasses with heads-up display that will stream in real time to a screen in your field of view, providing GPS, facial recognition, web info, entertainment (and ads)—operated by voice control and/or head motions. Image recognition tech will overlay names of colleagues or buildings, background on historic landmarks or artwork, restaurant or movie reviews. Will all this expand soon to plaster everyone on the street with nametags? Perhaps credibility ratings ... or the opinions and "reviews" of past dates or spouses?

    ==And more Science Fiction==

    An article about our ongoing efforts to use science fiction as a tool for teaching and stimulating bright minds -- Reading for the Future -- has been published in the December 2011 issue of VOYA (the magazine for young adult librarians).  It's a worthy effort that will continue at this year's World Science Fiction Convention in Chicago, next August. Read about how Sci Fi can help save the next generation and civilization! Tell teachers and librarians. And consider helping. Also see a collection of resources for using Science Fiction in the classroom.

    Isaac Asimov identified three basic types of science fiction scenarios: What if, If only and If this goes on…. Paul Di Filippo has written - in a cover piece for Salon - a fascinating review of two recent sci fi novels exploring Big Ideas of the ‘What if’ category. In Arctic Rising, Tobias Buckell spins a massive geoengineering project to counter climate change. Meanwhile Matt Ruff’s The Mirage is an alternate history in which America is a backward, fundamentalist nation, breeding terrorists responsible for destroying the World Trade Towers of Baghdad…Well worth a look.

    And now Elon Musk, of SpaceX, claims that within ten years, he will be able to send passengers to Mars (and back!) for $500,000. Science or science fiction?  Only a fool would bet against Elon.  So I might as well sign on!

    Comments

    Work for a company with the "ultracapacitor" amazingly dense energy storage: one Farad smaller than a paperback novel (yes Farad not micro, nor milli). GM looked at using them in cars: not enough raw materials in the Earth's crust.

    MikeCrow
    Which material(s)?
    Never is a long time.
    A mass driver capable of a modest mach 3 - mach 5 would be a great help for a SSTO system using a variable equivalence ratio rocket/ramjet/scramjet. Glad to see a reference to whirling tethers; We especially need proponents of tether technology now that Bob Forward is no longer with us.

    David Brin - I'm puzzled - are you implying that the launch vehicle would reach escape velocity of 11 km/s (25,000 mph) in the Earth's lower atmosphere? I would imagine such a velocity would produce significant heating, even more so than s shuttle experienced in the upper atmosphere. What sort of heat shield would be required?

    vongehr
    Rail guns and Neumann probes - or how to sell mediocre books by nurturing little white middle class boys' wet dreams, how cute. Also of course completely irrelevant given the geo-political situation and suchlike annoying "details".
    Most of these "augmented reality" gadgets are just kaleidoscopes. The Discovery Channel had a doc on once about some greasy guy who built a set of goggles claiming to give you "hyper reality" vision...I almost threw up and nearly stopped watching the channel.