WI: Voyager 1 mission decide on flybu of Pluto

In OTL when the launch of Voyager 1 was being prepared, the scientific team in NASA was debating whether they shall use the chance of closely investigating Titan or Pluto. Titan was picked because back then it was thought its atmosphere will be transparent to the cameras of Voyager, and because the engineers thought the spacecraft won't last long enough to reach Pluto.
Both observations proved to be wrong (the data of Titan was nothing groundbreaking and Voyager is still working for a given value of). So... WI Voyager 1 flies to Pluto past Saturn (the fly-by may happen somewhere around 1990)? How would this affect the future of long-distance spacecrafts?
 
I'm not sure if Pluto was in an appropriate position then, I think I read it something like this somewhere.

The launch of New Horizons in 2006 was justified on the ground that the planets were rightly aligned for a (relatively) fast travel to Pluto with the aid of the giant planets. Otherwise, New Horizons would have reached Pluto in 2020.
 
http://voyager.jpl.nasa.gov/faq.html
Question: Voyager 2, is it planned to ever reach Pluto?
Did either of the Voyagers visit Pluto?
Why didn't the Voyagers fly by Pluto?

Answer: Both Voyagers flew beyond the orbit of Pluto/Neptune in 1989, but neither flew by Pluto, which was elsewhere in its orbit at the time. It was never planned that the Voyagers would visit Pluto.

The original mission of Voyager was to explore Jupiter and Saturn. Two spacecraft were sent on slightly different paths, first to Jupiter and then, with gravity assists, on to Saturn. Voyager 1 could have been aimed on to Pluto, but exploration of Titan and the rings of Saturn was a primary scientific objective. This caused the trajectory to be diverted upward out of the ecliptic plane such that no further planetary encounters were possible for Voyager 1. Once Voyager 1 had successfully gathered data at Titan, Voyager 2 was allowed to go on to Uranus and Neptune. Voyager 2, theoretically, could have been aimed for Pluto, but the aim point would have been inside the planet of Neptune - not very practical. So Pluto was the only outer planet the Voyagers didn't visit.
Voyager 2 was impossible to redirect to Pluto, Voyager 1, however, was alternating between close fly-by of Saturn (they thought they could take shots of Titan in better quality than it turned out to be OTL) and aiming it to Pluto. In OTL the decision was made in favor of Titan.
 

Thande

Donor
We might not be able to give this WI the justice it deserves until we get the photos from New Horizons and then we'll have to judge what the Voyager cameras would have seen based on them.
 
http://voyager.jpl.nasa.gov/faq.html

Voyager 2 was impossible to redirect to Pluto, Voyager 1, however, was alternating between close fly-by of Saturn (they thought they could take shots of Titan in better quality than it turned out to be OTL) and aiming it to Pluto. In OTL the decision was made in favor of Titan.

I think this quote from NASA is a bit vague, like 'why do you ask stupid things?'. It's not that easy to 'redirect' space probs when the distances considered are that big; even if Voyager 1 were not pushed out of the ecliptic plane, would have been worthy to travel half solar system without an appropriate route that would have relied on the gravitational assistance of the giant planets? Maybe Voyager 1 would rest out of battery before that...

My answer would be: Voyager 1 could have encountered Pluto if not redirected to Titan, but it was not risk-worthy (chances for failing would have been much higher than opting for Titan). In my opinion, not realistic by that moment.
 
Just the general idea of "WI all major planets of Solar System are visited via fly-by by 1995" from the PoV of developing future missions, instead of purely scientific "WHAT we shall get from the probe" is pretty open for discussion even before May 2015, me thinks.
I think in case of success of this mission everything past Uranus will be considered as "too far and we've already been there", essentially abandoned for targeted spacecraft voyages just like Moon was. So no chances for OTL New Horizons - instead Juno launched earlier?

P.S. But I reserve the right to necro this in May.
 
My answer would be: Voyager 1 could have encountered Pluto if not redirected to Titan, but it was not risk-worthy (chances for failing would have been much higher than opting for Titan). In my opinion, not realistic by that moment.
Yes. Many even believed Voyager 2 won't survive long enough for proper encounter with Neptune, and the WI is pretty vague\improbable and implies some of "engineering clairvoyance" so to say, as they were unable to know whether they find anything interesting on Titan when they first programmed post-Saturn trajectory.
So the WI is pure musing when reading the articles on spacecrafts in preparation for January 26 (Dawn closeup of Ceres).
 

Delta Force

Banned
The Voyager Program was a cut down version of the Planetary Grand Tour proposal, which would have exploited an alignment of the outer planets that occurs once every 175 years, most recent in the 1970s. The Grand Tour was canceled in the budget cuts of the 1970s, along with many other NASA programs.
 
The Voyager Program was a cut down version of the Planetary Grand Tour proposal, which would have exploited an alignment of the outer planets that occurs once every 175 years, most recent in the 1970s. The Grand Tour was canceled in the budget cuts of the 1970s, along with many other NASA programs.
So... WI the budget cut is not so severe and 3 probes get build? Though this is past astronomy PoD and well into politics IMO.
 
Though unlikely, I am happy that Pluto was not explored then. If so, the limited capacity of the Voyager 1 would have only registered an icy rock just for being forgotten forever (not sure if it could have even detected all the minor moons).

Today we know that Pluto is probably one of the biggest examples of a different category of objects (Kuiper belt objects), so scientists can make a different approach for its study and I hope New Horizons could compare it with the possible second target object.

Future missions might consider Eris and Sedna as targets, because they seem to belong to a different group of objects; but I'm afraid we might not see this in our lifetimes.
 
Ironically the data which could have played crucial role in the choice of trajectories was received only in 1979 from Pioneer 11 (no exploration of surface of Titan is possible from fly-by). But it was IIRC already the point of no-return from Titan fly-by trajectory for Voyager 1.
So it's either enough budget to launch Pioneer 3 or earlier launch of Pioneer 11 so the data on it arrive on Earth while it's still possible to intervene with Voyager slingshot maneuver?
The first probe to visit the Saturnian system was Pioneer 11 in 1979, which confirmed that Titan was probably too cold to support life.[121] It took images of Titan, including Titan and Saturn together in mid to late 1979.[122] The quality was soon surpassed by the two Voyagers, but Pioneer 11 provided data for everyone to prepare with.
Titan was examined by both Voyager 1 and 2 in 1980 and 1981, respectively. Voyager 1's course was diverted specifically to make a closer pass of Titan. Unfortunately, the craft did not possess any instruments that could penetrate Titan's haze, an unforeseen factor. Many years later, intensive digital processing of images taken through Voyager 1's orange filter did reveal hints of the light and dark features now known as Xanadu and Shangri-la,[123] but by then they had already been observed in the infrared by the Hubble Space Telescope.
 
Plus, the fact is that Titan was and remains one of the most interesting bodies in the Solar System. It would have been almost criminal to pass up the opportunity to fly past Titan...you can't blame NASA for the fact that the surface was not visible. Actually, that in itself helped to demonstrate that Titan had a thick atmosphere, possibly with high enough pressures for surface liquids.
 
Deciding on a Pluto flyby is highly improbable short of a scenario where more Voyager-type probes are launched and therefore Voyager 2 is not tasked with completing the Uranus and Neptune flybys (as I wrote about in Eyes Turned Skywards, here and here, based directly on NASA documents from the period). Besides Titan being relatively more interesting (remember, extremely little was known about Pluto even in 1977; Charon wasn't even discovered until 1978!), the experience of the 1960s had made mission planners extremely wary of vehicle reliability, so they wanted to avoid the long flight times that would be needed for a spacecraft to reach Pluto. If they have two, they might well go "eh, what the hell," especially once Titan turns out to be shrouded in opaque haze; otherwise, they almost certainly won't. In retrospect, they were overly cautious, but they couldn't know that at the time...
 
I thought Voyager 1's trajectory, which takes it out of the ecliptic altogether (I recognize Pluto isn't on the ecliptic) was designed to measure the density of the rings by beaming transmissions back to Earth through them.

Is the geometry in 1980 favorable to Voyager 1 getting a look at the rings *and* encountering Pluto?

Also, there were concerns that Voyager 2 would not have the reliability to make it as far as Neptune. I could see concerns about compromising Voyager 1's mission for a chance at Pluto. It's a long haul.

Finally, if you don't bank sufficiently with respect to the ecliptic, you can't take a pretty "Family Portrait" of the solar system 15 years later. :)
 
I thought Voyager 1's trajectory, which takes it out of the ecliptic altogether (I recognize Pluto isn't on the ecliptic) was designed to measure the density of the rings by beaming transmissions back to Earth through them.

They may have done some radio science activities, but Voyager 1's trajectory was 100% determined by their desire to do a close Titan flyby. The trajectory that it followed was the best available for the Saturn flyby, in terms of achieving that and getting a good look at the other moons. For this reason, I believe that in any other timeline where a mission is launched in 1977 to follow a Grand Tour trajectory, it is extremely probable that there will be a step-by-step duplicate of Voyager 1 launched (of course, it may have different technologies on board, but it is an absurdly good launch opportunity).

Also, there were concerns that Voyager 2 would not have the reliability to make it as far as Neptune. I could see concerns about compromising Voyager 1's mission for a chance at Pluto. It's a long haul.
Yes, there were significant reliability concerns. People were recalling the 1960s, when seemingly half of the spacecraft they launched failed, and didn't realize that they had largely cured the underlying issues through better technology and quality control.
 
Bumping this because July and encounter is nearing
4oLNlhebQCM.jpg
 

Archibald

Banned
Yes, but this picture is even better
pluto_charon_150709_color_final.png


As said above, they chose to send Voyager to flyby Titan on a trajectory that got it out of the solar system for two reasons. First, Titan was more interesting. Two, noone knew if Voyager could last that long.
Truth was, JPL in fact already knew Voyagers could handle Uranus, Neptune and even Pluto: those assholes had deliberately over-engineered the probes just in case. ;)
The real threat was budgetary: early in the 80's Reagan OMB threatened to cancell the whole planetary exploration budget. As for NASA they were ready to do that to save money - their argument was that a better planetary exploration program would exist if it used the shuttle, space station Freedom, and the Orbital Transfer Vehicle (that was never build)

Serious consideration was given to shut down Voyager after Saturn. In this case Voyager 2 would flyby Uranus but noone would listen. :(
 
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As said above, they chose to send Voyager to flyby Titan on a trajectory that got it out of the solar system for two reasons. First, Titan was more interesting. Two, noone knew if Voyager could last that long.
Truth was, JPL in fact already knew Voyagers could handle Uranus, Neptune and even Pluto: those assholes had deliberately over-engineered the probes just in case. ;)

Well said, Arch.

As Goblin says, Voyager was what JPL salvaged out of the original TOPS "Grand Tour" proposal that Congress (more specifically Chairman Joe Karth of the House Subcommittee on Space Science and Applications) rejected in 1971. JPL hacked the design down to something that cost less than a third ($250 million and change) of the original design proposal, now provisionally called MJS77 for obvious reasons, which turned the trick. But one other cost-saving move was to restrict the MJS77/Voyager mission profile only to Jupiter and Saturn. Both *would* have a trajectory that would take them, or could take them, past Uranus and Neptune, and possibly, Pluto. But that would require funding the office for another decade, and that was more money than they were likely to get.

But Bud Schurmeier and John Casani, the original Voyager manager and deputy, had indeed worked to build two probes robust enough to last, they hoped, well beyond the designed mission life. Casanai was so confident that the probes could make it to at least Uranus that he asked JPL's switchboard for a "6578" extension - because it spelled out "MJSU."

That said, no one knew if the design really *was* going to be robust enough to keep the probes active as far out as Uranus and Neptune - that would require nearly another decade of travel in the hostile vacuum of deep space, after all. Such a feat had never been attempted before. And that was a consideration in the energetic debate over whether to send Voyager 1 past Titan or not. Well, that, and the persuasiveness of Carl Sagan. And Sagan lobbied very, very hard in private and public for the Titan diversion, before launch and after it, enough so as to overcome even the risks involved in sending Voyager 1 past Titan's south pole (which were not negligible). As Jeffrey Kluger noted wryly:

When Carl Sagan started going on about organic chemistry and the best you had to counter with was a lot of fretting and hand-wringing about 4,000 mile miss distances, there was little question whose argument was going to prevail. (Moon Hunters, p. 205).

So if you want to make this timeline work, your best bet may be to place Carl Sagan under a bus as your P.O.D.

But even so, the logic for Titan made a certain sense at the time. Titan *was* already known to be a very interesting place, perhaps the most interesting place in the Outer Solar System, because it had a robust atmosphere with lots of organic compounds, no less. And the probes were only funded to stay alive as far as Saturn, and there was no guarantee they'd still be operating in 1986 (Uranus) or 1989 (Neptune), let alone Pluto. It was only after the Saturn flybys, in 1981, that Congress finally approved extending the Voyager mission to those planets.

I do think that a Pluto flyby by Voyager would reduce the chances of getting New Horizons done, at least when and how it actually happened. Pluto would have been visited on a flyby already, and the instruments on board would not have told us nearly as much as New Horizon's will. Knowledge of the nature and extent of the Kuiper Belt did drive some of NH's cause, of course, and that would have come to the fore by the late 90's as well. But it's harder to make the case for the first New Frontiers mission to go to Pluto when it's already been visited. And New Horizons had some considerable opposition in OTL as it was. Perhaps New Horizons will turn up some real surprise that Voyager could also have detected, and that will change this calculus - if so, we will know soon enough. But I doubt it.
 
I think if one of the Voyager spacecraft made it to Pluto, the results would not be promising.

The reason is simple: the digital image sensors on the Voyager spacecraft was pushing right at the limits of getting clear images from Neptune, and the Voyager images of Pluto--assuming it passes by Pluto in circa 1990-1991--wouldn't be that clear. The sensors on New Horizons were designed to operate in the very low-light situations of the outer Solar System, and as such that's why the images from Pluto are far better in quality.
 
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