• Question: can you explain the thing that spaceships do called a gravity assist?

    Asked by 298grak45 to Daniel, Maggie, Ry, Scott on 15 Nov 2017.
    • Photo: Ry Cutter

      Ry Cutter answered on 15 Nov 2017:

      Gravity assist is like a slingshot for spaceships!
      Because gravity can cause acceleration, we can use it to speed up spaceships and alter their path. It’s sort of like how a snowboarder uses the hill to speed up in one direction so they get lots of height:

      Spaceships whip round the planets using the gravity, the closer to the planets they get the faster they can come out. Scientists even time rocket boosters with this so the spaceships come out even faster! This saves money on fuel and time. We have it so accurately now we don’t even fire our spaceships in the direction they’re going, we just launch them in the direction of the slingshot 🙂
      When the slingshot happens, the spaceship steals a little bit of the orbital speed of the planet. That means if we were to do it enough (well over 100 Billion times), the planet would eventually stop orbiting in it’s orbit and fall into the sun!
      Great Question,
      Ryan

    • Photo: Maggie Lieu

      Maggie Lieu answered on 15 Nov 2017:

      To make a spaceship go faster, you need a lot of fuel! but its really expensive to bring fuel from Earth into space.
      So one thing we can do is to use the gravity of planets to help us go faster. The idea is that as your space craft approaches a planet it gets pulled by the planets gravity and gets faster but when it leaves the planet the space craft is still being pulled back by the planets gravity so it would slow down again so overall there should be no gain in speed right? Wrong! This is because the planet is not still, it orbits the sun. So if the satellite leaves the planet in the direction that the planets is moving then it also gets this speed boost

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