3 ms·

How do you decelerate once you get there though?

• GMoromisato 1y ago
  By “delta-v” I mean propellant budget, not initial velocity. So you spend half your delta-v to accelerate out and the other half to decelerate. But of course, the initial delta-v costs a lot of propellant because it has to push an almost full tank. By the time we have to decelerate the ship will be a lot lighter. That’s why you needed a full Saturn 3rd stage to send Apollo to the moon, but just the service module to get back to Earth. I realize now that “a lot of delta-v” is an understatement. 500 AUs is ridiculously far. To get there in under a century you’d need fission-fraction reactors, well beyond our current tech.
  • kadoban 1y ago
    > I realize now that “a lot of delta-v” is an understatement. 500 AUs is ridiculously far. To get there in under a century you’d need fission-fraction reactors, well beyond our current tech. Voyager 1 is 166 AU away, it launched about 50 years ago. So wouldn't we just have to do about twice as well as that, or launch 2 of them in opposite directions? That sounds _very_ hard (Voyager is amazing), but it can't be beyond our current tech, right? We did fairly close to that 50 years ago.