Comment by imoverclocked

Comment by imoverclocked 9 days ago

8 replies

This would be neat to see in space where the fallout wouldn't be an environmental issue. I have to wonder if anyone with significant credentials has considered a high-thrust nuclear ion-drive yet. Certainly sci-fi has!

akira2501 9 days ago

> the fallout wouldn't be an environmental issue.

"It's outside the environment."

> has considered a high-thrust nuclear

Of course we have. Always start at NTRS: https://ntrs.nasa.gov/citations/19690000736

> Certainly sci-fi has!

Our Solar system is a gravitational well that tends to put things in solar orbit. You really want the waste products to leave the solar system, which isn't terribly difficult, or you want them to land on the sun itself, which is exceptionally difficult.

  • WillPostForFood 9 days ago

    Our Solar system is a gravitational well that tends to put things in solar orbit. You really want the waste products to leave the solar system, which isn't terribly difficult, or you want them to land on the sun itself, which is exceptionally difficult.

    Yes, it is counter intuitive but it takes less energy to leave the solar system get to the sun (you have to cancel out the Earth's orbital speed). Something learned from Kerbel Space Program.

    • pmontra 9 days ago

      Time ago I read that the cheapest way to do it (energy wise) is going very far away, let's say entering Pluto's or Neptune's orbits, cancel out the orbital speed there (it's lower than Earth's one) and then fall into the sun. It takes quite a bit of patience.

      • vikingerik 9 days ago

        Right, this is a bi-elliptic transfer, which is delta-v-cheaper than a Hohmann transfer for widely separated orbits. https://en.wikipedia.org/wiki/Bi-elliptic_transfer

        In practice in the real solar system, the cheapest way to get from Earth to the Sun is to use Jupiter. Launch to there and reverse-slingshot to cancel out the orbital velocity and drop directly towards the Sun. The Parker Solar Probe would have done this, although decided not to because of the complications in designing to handle both the cold of Jupiter and the heat of the Sun.

  • adrianN 9 days ago

    I’m okay with waste products on an orbit that doesn’t make them rain on Earth for a few dozen millennia.

    • recursive 9 days ago

      Why would it be okay to rain the waste products on earth in a few dozen millenia. Do you think life will be over by then?

      • adrianN 8 days ago

        All the really dangerous isotopes have decayed by then.

  • [removed] 9 days ago
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