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Comment by itslennysfault | Hacker News Reader

Ya know...... Considering how long it takes these things to get to deep space we probably should've kept the Voyager program going. By that, I mean we should've continued iterating and launching Voyager probes. If we launched one every 2 or even 5 years we'd have between 22 and 9 additional probes heading into deep space a couple years apart. Each with slightly better tech than the previous.

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There are 2 problems with this:

1. Voyager was launched at that particular time because a particular alignment of planets (known as the "Grand Tour") allowed for MASSIVE gravity assists that made this mission possible. This alignment happens very rarely (I think like ~200 years)

2. Opportunity cost. Yes we could have done this, but what would we have gained? Mostly we would get the same data over and over again. Resources are not infinite. Would you rather another Voyager mission, or Hubble?

It’s “only” every 176 years ;)

I figured the justification was #2, and my answer is obviously give space more budget and do both, but I know the government doesn't tend to align with my priorities.

However, #1 (it's literally not possible) didn't even cross my mind and shows my naivety when it comes to space travel. Super interesting info. Thanks for sharing.

I would say it's been followed up plenty of times. There have been some incredible probes with unique capabilities, that have traveled the solar system since the launch of Voyager.

Agreed. Every time I see a story about the Voyagers, I wonder why a follow-up hasn't been done that is much faster and more capable.

It's the same reason the Voyagers launched in the late 70s - the Grand Tour configuration of the planets [0]. The outer planets align in a way that lets you chain together several gravity assists to achieve high enough speeds to escape the solar system. The trick is that configuration only occurs every 175 years. I don't think we have any space vehicles right now that could produce that same kind of delta-v with their own chemical/electrical/nuclear power.

[0] - https://en.wikipedia.org/wiki/Grand_Tour_program

It's feasible to do an alternate route to the outer solar system by using an ion engine, dropping the perihelion down below Venus's orbit and then using a Venus -> Earth gravity assist chain with the ion engine going the whole time. The downside is that this is a more lengthy process than the Grand Tour route, and you have to do all your maneuvers in the inner solar system because ion engines draw a lot of electrical power and solar panels get very weak once you get past Mars or so.

Probably because it made more sense to use the general information obtained from the Voyagers to design probes with specific capabilities to explore specific planets. The Cassini/Huygens mission might be a possible example.

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