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Research for Science Fiction Story

  1. Apr 15, 2017 #1
    I'm researching a topic for a sci-fi story. One of the elements is a "space glove", basically a network of nets that "catch" rods of ballistic projectiles launched from the peaks of mountains by railgun. Any comments or insights would be helpful. Here is a data dump of my scribblings on the topic.

    Space Glove
    Orbital system of nets that catches raw materials launched by railgun as ballistic projectiles.
    size of net to establish 95% confidence of catch
    Mass of net Mn using known materials (what would these materials need to be?)
    Challenge: Railgun exit velocity necessary for projectile to achieve low earth orbit and have necessary tangential velocity to ensure catch without net breakage. Assume ground launch at 6,000 meters (i.e. Dinali or similar peak). What is the energy necessary and what is the marginal cost of each launch? My hypothesis is that marginal cost is a fraction of current launch technologies.

    Assuming catch successful, given mass Mp of projectile and Tangential Velocity of projectile Vx, how much fuel Mf is necessary to re-establish orbital velocity of net?
    Mass Mp of projectile needed to carry re-orbital velocity fuel Mf + 100kg of raw materials. We are assuming that projectiles will carry raw materials plus fuel to pay for momentum loss during catch.
    Surface area / shape / tangential velocity necessary of projectile at time of catch needed to ensure glove does not break

    I'm thinking that we are launching a ceramic tipped rod of (net materials) that will expand for "the catch". It would also need to contains fuel. First several years of launches would self assembling nets to increase the capacity of our Space Glove launch system.

    How many nets to accommodate a railgun launch every 60 seconds.

    At this launch capacity, space glove would enable low cost launching of 52,560,000 kg of raw materials per year. How long before we could have...
    - Orbiting solar cells to power entire countries via microwave relays
    - Planetary defenses from rogue asteroids
    - Orbital debris cleanup programs
    - Human habitats
    - Building of space factories
    - Launch platforms for exploratory programs & asteroid mining
     
  2. jcsd
  3. Apr 15, 2017 #2

    DaveC426913

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    Gold Member

    Since the payload is launched via railgun, does that mean its casing at least is strongly ferrous? If not, why not make it so? Then the space glove can be magnetic, simply reversing the ballistic velocity. You'll need to account for trajectory drift though.

    I think you could set up an energy recovery system, which could power subsequent launches, or simply power the retrieval station.

    With such high volume interplanetary passages, you'll want to close the energy loop as much as possible - so your system doesn't hemorrhage energy at interplanetary scales.
     
  4. Apr 15, 2017 #3
    Would a centrifugal catapult work for launching loads?
     
  5. Apr 16, 2017 #4
    Intriguing. You could line up and fire multiple projectiles at the perimeter and energy can be conserved. Braking for reload could recharge the batteries. Cool idea.
     
  6. Apr 16, 2017 #5
    You could fling two loads at once. Different directions, but if the orbits are right...
     
  7. Apr 16, 2017 #6
    My thought on that. Have an asteroid as the "core" of the Slinger. Two long structures (arms) at the "poles". Shipments are delivered to the asteroid and placed on the base of the arms. The rotation of the rock pushes the loads out along the arms and they sail off toward their destination(s). Balance the two loads with something always needed or at least useful, like water. The loads could have rockets attached to adjust their trajectory. The destination orbits would gradually get "out of alignment" with the Slinger's trajectories, and local tugs would be in business to retrieve them and nudge them to their end point. (This scenario would open up the possibility of competition for the loads, up to and including piracy and armed ships confronting each other for the loads.

    Each major destination would have it's own Slinger, of course. Important but low priority loads would be flung in off-angle days, and be picked up when there was nothing else to do. Rather like the "cod grind" in "Deadliest Catch".
     
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