4 ms·

My understanding is that 1. Our rocket / propulsion technology today may be cheaper (thx largely to SpaceX), but it doesn't really necessarily provide MUCH mor

My understanding is that 1. Our rocket / propulsion technology today may be cheaper (thx largely to SpaceX), but it doesn't really necessarily provide MUCH more delta V. Meanwhile 2. Voyager launches relied on a once-in-a-blue-moon (not quite once in two centuries) alignment of various planetary bodies to give a spectacular orbital slingshot boosts. So my limited understanding is that we can't really overtake voyagers very easily. Whether our current technology coild be made more reliable in the long term is another good point of discussion :-)

vikingerik 2y ago
The alignment isn't what matters for overtaking Voyager. Jupiter alone is enough, and New Horizons nearly did. Jupiter accounts for the vast majority of any gravity-assist plan. Saturn has 30% the mass and 2/3 of the orbital velocity, so it could only add 20% more over what you get from Jupiter alone, and the ice giants are smaller and slower yet.
- Denvercoder9 2y ago
  > New Horizons nearly did. New Horizons didn't nearly overtake Voyager. It's currently traveling about 4 km/s slower, and as it's still closer to the Sun, it's also decelerating more.
  - vikingerik 2y ago
    Yes, I wrote that short for brevity. If you must have the full thing spelled out: New Horizons nearly got enough velocity at Jupiter to eventually overtake Voyager. 4 km/s is "nearly" in astronomical terms. New Horizons wasn't really trying to optimize for speed at Jupiter (its closest approach was over 10m km), and a spacecraft that did could easily overtake Voyager using Jupiter alone and not need an alignment with Saturn or anything else.
pavon 2y ago
The alignment was important in that it allowed Voyager 2 to visit Jupiter, Saturn, Neptune and Uranus in a single mission using gravity assists. The final velocity of Voyager could be matched in other ways, but not exceeded by so much that a probe could catch up to the Voyagers any time soon.

vikingerik 2y ago

The alignment isn't what matters for overtaking Voyager. Jupiter alone is enough, and New Horizons nearly did. Jupiter accounts for the vast majority of any gravity-assist plan. Saturn has 30% the mass and 2/3 of the orbital velocity, so it could only add 20% more over what you get from Jupiter alone, and the ice giants are smaller and slower yet.

Denvercoder9 2y ago
> New Horizons nearly did. New Horizons didn't nearly overtake Voyager. It's currently traveling about 4 km/s slower, and as it's still closer to the Sun, it's also decelerating more.
- vikingerik 2y ago
  Yes, I wrote that short for brevity. If you must have the full thing spelled out: New Horizons nearly got enough velocity at Jupiter to eventually overtake Voyager. 4 km/s is "nearly" in astronomical terms. New Horizons wasn't really trying to optimize for speed at Jupiter (its closest approach was over 10m km), and a spacecraft that did could easily overtake Voyager using Jupiter alone and not need an alignment with Saturn or anything else.

pavon 2y ago

The alignment was important in that it allowed Voyager 2 to visit Jupiter, Saturn, Neptune and Uranus in a single mission using gravity assists. The final velocity of Voyager could be matched in other ways, but not exceeded by so much that a probe could catch up to the Voyagers any time soon.