The Voyager probes were getting a lot of funding and were rushed out due to a very favorable alignment of planets which meant we could send out a single probe (or in this case two for redundancy) to multiple planets. These aligments of the outer planets is quite rare and only happens about every second century. So it made sense to spend a lot of resources on something that were way ahead of time. Since then our probes have been much more reasonable in terms of budget. However they have been able to take advantage of more modern technology. We have revisited the planets and moons that the Voyager probes visited with better instruments and more time. And currently we have New Horizons which did a flyby of Jupiter, Pluto and Ultima Thule and is aiming to flyby more objects in the Keuper belt if the opperutiny presents itself. It is already studying several of the structures that the Voyager probes discovered at the edge of the solar system.
The Voyager craft were launched at a specific date when the planets lined up (as far as a spacecraft is concerned) so that as each planetary flyby occurred the craft could get a slingshot boost meaning that the mission was completed in a relatively short length of time, there was even a rush to get the craft ready in time to match the timing. https://youtu.be/Zu-Sp3I0c1Q
Time, money, and interest.
There have beeen some other deep space craft (notibly New Horizons).
They are extremely expensive. New Horizon cost $565 million just to make and launch. Another $215 million to run the operations center while it is travelling and operating. NASA has a limited budget and has to prioritize what it will do and when.
Part of the problem is that while we get a lot of information from these craft, most of it is completely academic. I just want to say that I completely support spending money on these projects, but it is still a consideration when it comes to justifying budget amounts for government spending. For a lot of the public, I don’t think your going to get a lot of support if you asked “Would you be willing to spend nearly $1 billion tax dollars so we can take a better picture of Pluto?”. The mission gathered far more than just that. But I guarantee you that’s the only result the majority of the public has seen.
A lot more effort has been made into sending up missions that produce a commercial result (communications satellites such as Starlink for example). There are still investments being made into the pure science missions, but they are a lot more difficult to get done.
Latest Answers