15 votes

This is why we don't shoot earth's garbage into the sun

10 comments

  1. etiolation
    Link
    1. The possibility of a launch failure. If your payload is radioactive or hazardous and you have an explosion on launch or during a fly-by with Earth, all of that waste will be uncontrollably distributed across Earth.
    2. Energetically, it costs less to shoot your payload out of the Solar System (from a positive gravity assist with planets like Jupiter) than it does to shoot your payload into the Sun.
    3. And finally, even if we chose to do it, the cost to send our garbage into the Sun is prohibitively expensive at present.
    11 votes
  2. [4]
    bub
    Link
    So if it doesn't make sense, from an energy perspective, to send garbage from Earth into the sun, because it takes less energy to send it out of the solar system, then is there another place in...

    So if it doesn't make sense, from an energy perspective, to send garbage from Earth into the sun, because it takes less energy to send it out of the solar system, then is there another place in the solar system where it does make sense?

    The outer planets have much lower orbital velocities than the inner planets, so if we had, say, a colony or base on one of Saturn's moons, it would take less energy to "de-orbit" some payload enough that it falls into the sun, right?

    But, since something out there would have a lower solar escape velocity too, would it still be the case that it would take less energy to launch it out of the system?

    I admit I don't really want to do the math...

    3 votes
    1. [2]
      cstby
      Link Parent
      Not a rocket scientist here, but I'm pretty sure your orbital velocity increases as your orbit gets lower. It would be harder to send garbage into the sun from the outer planets and easiest from...

      Not a rocket scientist here, but I'm pretty sure your orbital velocity increases as your orbit gets lower. It would be harder to send garbage into the sun from the outer planets and easiest from Mercury.

      1 vote
      1. bub
        Link Parent
        Higher orbital velocity is what makes it harder to send things into the sun, not easier, because you have to "slow it down" more, so to speak.

        Higher orbital velocity is what makes it harder to send things into the sun, not easier, because you have to "slow it down" more, so to speak.

        2 votes
    2. Kuromantis
      Link Parent
      I'm pretty sure that's true, assuming you pick a moon far out enough that climbing out of the giant planet's gravity well isn't harder than Earth's to the point where the decreased planetary...

      The outer planets have much lower orbital velocities than the inner planets, so if we had, say, a colony or base on one of Saturn's moons, it would take less energy to "de-orbit" some payload enough that it falls into the sun, right?

      I'm pretty sure that's true, assuming you pick a moon far out enough that climbing out of the giant planet's gravity well isn't harder than Earth's to the point where the decreased planetary orbital velocity isn't worth it. (Not that moons that orbit at a distance where escape velocity is much lower than Earth are uncommon.)


      Similarly, wouldn't it be easier to send ships to one of the outer planets (likely Saturn or Uranus) and get a backwards gravity assist from them to reduce your solar orbital velocity to 0? The main challenge is getting an orbit which, when entering the gravitational dominion of the planet:

      • Intersects the outer planet at roughly the same velocity (relative to the planet) at which it orbits the sun.

      • Intersects the outer planet at an angle where the planet's gravity can bend the hyperbolic orbit to be retrograde to the planet's orbit when escaping the planet

  3. [2]
    callmedante
    Link
    Even though I've been saying for years we should launch our nuclear waste into the Sun, I am reminded that I am not, in fact, a rocket scientist. I never knew that gravity would be such an...

    Even though I've been saying for years we should launch our nuclear waste into the Sun, I am reminded that I am not, in fact, a rocket scientist. I never knew that gravity would be such an obstacle, and I never considered the possibility of a launch failure and the ensuing global catastrophe.

    Good thing they never asked me. (For once!)

    2 votes
    1. NoblePath
      Link Parent
      Incidentally, the same risk, albeit on a smaller scale, exists when shipping nuclear waste to a central location, like the southwestern salt mine storage facility.

      Incidentally, the same risk, albeit on a smaller scale, exists when shipping nuclear waste to a central location, like the southwestern salt mine storage facility.

      4 votes
  4. [3]
    Echinops
    Link
    It would be much cheaper and easier to simply throw out trash into active volcanoes.

    It would be much cheaper and easier to simply throw out trash into active volcanoes.

    1. gco
      Link Parent
      That approach has the potential of spreading the waste or components to it throughout our atmosphere so likely something that will exacerbate climate change.

      That approach has the potential of spreading the waste or components to it throughout our atmosphere so likely something that will exacerbate climate change.

      2 votes