What changes to Voyager could have been made?

Question

If during the planning and construction of the Voyager missions they knew what we know now, what changes to the missions would have been most helpful in augmenting the science obtained?

I guess "what we know now" only refers to knowledge about the solar system and not about technology? — asdfex, Feb 04 '23 at 16:59
Well if we knew then what we know now we could get Voyager to investigate different things altogether. — DKNguyen, Feb 04 '23 at 20:53
Does "We know moon 19##P## exists, so we can schedule multiple pictures of it at best illumination and/or closest approach instead of discovering it months or years later in images of something else." count? Heck, Shoemaker-Levy 9 might have already been orbiting Jupiter during the Voyager flybys. — notovny, Feb 04 '23 at 21:24
As it stands this question looks like idea-generation, without a clear focus. Every answer provides a different aspect, but no single answer can objectively be the "right" answer. Without a clear format this seems no good fit for the Q&A format of stack exchange. — Falco, Feb 06 '23 at 10:18
Are you asking about changes to the spacecraft or changes to the mission? The missions took advantage of a once in a century (if not longer) alignment, but there were other options. The spacecraft themselves were designed using what we would now call stone age devices (the stone age of computing and sensors). Which are you asking about, the mission designs or the spacecraft designs? — David Hammen, Feb 06 '23 at 14:40
What changes. Plenty. We could have done any number of things. We could have made it be in the shape of a banana. @user277093 — Starship - On Strike, Mar 05 '23 at 14:22

score 33 · Answer 1 · answered Feb 04 '23 at 12:41

Knowing what we know now about Titan's thick and resistant-to-surface-photography atmosphere, choosing a Pluto flyby for Voyager 1 over a Titan flyby would perhaps have given more exciting results. Voyager 1 had the capability of flying by either but not both of these, as going by Titan gave the wrong exit angle from the Saturn system to subsequently fly by Pluto.

Instead, we had to wait until 2015 to get a closer look at Kuiper belt objects with new Horizons.

score 14 · Answer 2 · answered Feb 05 '23 at 12:35

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A simpler question is what wouldn't have changed. The answer to that is simple: The power source, and possibly propulsion. We still use pretty much the same radioisotope thermoelectric generators (invented in 1954) that powered the Voyager spacecraft to this day. Whether the Voyager spacecraft would have used the same kind of propulsion that it did use is perhaps debatable. I suspect they would not have used the propulsion systems used on Voyager if they had a choice of modern alternatives.

Cameras have improved a lot. If the designers of the Voyager spacecraft had the choice of using the camera technology of today versus what they had then it would be an easy choice. They would have chosen the camera technology of today.

The biggest improvement since the Voyager era is in computation and data storage. Computing systems, even the lousy ones that deep space missions tend to use / are forced to use, have changed by multiple orders of magnitude since the Voyager era. For example, the computers on the Voyager spacecraft had 32K words of memory. I'm amazed they did so much with so little memory.

The New Horizons spacecraft, which had a considerably lower budget than did the Voyagers, took advantage of those huge improvements in computing and data recording technologies. Computation and data recording were extremely limited in the Voyager era. Those wonderful images of Pluto from New Horizons simply would not have been possible using Voyager era technology. The New Horizons spacecraft took its sweet time (well over a year) to transmit those recorded wonderful images back to Earth. The Voyager spacecraft didn't have that ability.

answered Feb 05 '23 at 12:35

David Hammen

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Two big advantages in modern computer technology are they are significantly more power efficient, and we have made significant advances in error correcting codes for sending signals over noisy channels. The combination of these factors would allow the Voyager spacecraft to extend the missions even further, as the RTG power level dropped, and the spacecraft get further from earth. – user1937198 Feb 05 '23 at 20:31
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Data recording for sure. I think Voyager had a tape recorder. – Organic Marble Feb 05 '23 at 22:09
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I've heard that during mission planning, it wasn't even 100% given that Voyager would carry a computer at all. It took some convincing to reach that decision (Source: personal communication with someone who was on the science team). – gerrit Feb 06 '23 at 11:09
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@gerrit This gets into the tricky question of what makes a computational / sequencing device a "computer". Designers of device drivers to this day oftentimes object to the devices they design being called "computers." While those drivers typically don't have a main() or an operating system, those device drivers / sequencers are still "computers" in my mind, and more importantly, are "computers" in the minds of many others. – David Hammen Feb 06 '23 at 14:00
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I would think that the power source would have been designed to last longer if anyone had any clue that the power supply would be the limiting factor for mission duration. – supercat Feb 06 '23 at 23:48
@supercat Like many space missions, the Voyagers had primary and secondary missions. The secondary objectives were not a part of why Congress funded the vehicle. They were a nice to have bonus. Increasing the longevity by using an isotope with a longer half life (e.g., Am-241) would necessarily decrease the power per unit mass. This would have required increasing the mass so as to enable the vehicle to achieve its primary mission, so maybe not a good thing. Besides, we don't have Am-241 RTGs yet. – David Hammen Feb 07 '23 at 09:32
@DavidHammen: My point is that the aspect of the mission which was least foreseen in the 1970s was the idea that anyone 50 years later would care if the RTGs were still working. Of course, there's no real way of knowing how much more would be achieved if the lifetime of the RTGs were extended by another 5-10 years, or were doubled, since until the probes reach certain areas of space there's no way of knowing whether they'll reveal anything unexpected. – supercat Feb 07 '23 at 16:11

score 7 · Answer 3 · answered Feb 05 '23 at 20:47

I think the simplest answer with no "back to the future" aspects would be that what we know now is that the Voyagers are still alive an kicking and providing new science!

Thus they might have considered finding a way to include the mass and heat of a second RTG somehow to double their available electrical power and warmth in the 2020's and 2030s.

This is not at all trivial task and I'm not saying they'd be able to do this; those RTGs were heavy and of course produced a lot of heat, so it would be a significant design challenge for the spacecraft and the payload considerations during launch.

They might also look into adding more of the small radioisotope heaters for some instruments.

In the end they might instead say "nah, if this works there'll be plenty of funding for a second round of Voyagers in a decade, let's just get these out there for now.

What changes to Voyager could have been made?

3 Answers3