Voyager to Pluto

By Phil Plait | October 1, 2006 11:57 am

I blogged recently about David Seal’s writing as a stand-in for Emily Lakdawalla on The Planetary Society Blog. He’s a great writer, and I think he should start his own blog. He obviously has a passion for what he does, and isn’t that fun to read?

For his last entry as a guest, he wrote about how the Voyager probes could have been sent to Pluto. In the end, the probes did a "Grand Tour" of the outer giant planets (Voyager I went to Jupiter and Saturn, while it’s brother Voyager II went on to Uranus and Neptune), but Pluto was simply too far back in its orbit to be reached.

What I didn’t know is that a visit to Pluto was possible, just not chosen. It could have been done, but only by not visiting Uranus and Neptune. Once at Saturn, the probe had to be aimed just right to visit the other two big planets, or a different course set to go on to Pluto. The mission designers made a choice, and I think it was the right one– right for the time it was made, and still right today.

Anyway, go on and read David’s post. I think I’ll drop him a line and tell him he should set up his own blog. I bet he’d do just fine.

CATEGORIZED UNDER: Astronomy, Cool stuff, NASA, Science

Comments (11)

  1. tacitus

    You mean there was something I’ve known for 25 years about space that the BA didn’t…. wow, who’da thunk it?

    I recall people discussing it at the time, and I always thought it was a shame that they didn’t send Voyager 1 to Pluto instead of sending it up out of the planetary plane. Of course, I didn’t know anything the desire for a close flyby of Titan, but I do remember that they also wanted to fly through the ring plane to get a good look from through and above/below the rings.

    I fully understand the reasons why Pluto was not deemed to be a good option at the time, and they made the right choice, but it’s something I’ve always had a nagging “what if” feeling about.

  2. Andy

    Hmmm… interesting, but really Titan+Neptune+Uranus > Pluto, and that’s the end of it.

  3. Chip

    The idea of reaching a point earlier in the mission for a possible “Jupiter-Pluto transfer with a flight time of only seven years” caused me to daydream of a science fiction scenario (requiring a different design for Voyager 2.) If Voyager 2 were capable of detaching a smaller craft that had its own propulsion, altering its course to Pluto, then Voyager 2 would continue its separate grand tour of the gas giants. But then you’d have two missions-in-one probably requiring a bigger budget.

    Nevertheless, it would be interesting some day to really see what Pluto looks like.

  4. Andy

    “Voyager 2 were capable of detaching a smaller craft”

    Actually, it would probably have been cheaper to just launch them both on the same rocket as seperate craft. It would have meant some serious weight scrounging, too, and then you’d have three individual spacecraft instead of two copies of the same design. Or you could have had three launches….

    Besides, we won’t have to wait too much longer for some close-up data on Pluto. What is it? 2013? Really in the grand scheme of things, that’s not much time, plus we’ll get a change at possibly flybys of other TNOs that weren’t even discoevered yet in the 1970s.

  5. Chip

    “Actually, it would probably have been cheaper to just launch them both on the same rocket as seperate craft.”

    Yes – you’re right! (I was day dreaming, so I guess everything had to look more dramatic.)

    “Besides, we won’t have to wait too much longer for some close-up data on Pluto.”

    That will be very cool.

  6. CR

    I, for one, can’t wait!

  7. ioresult

    Dear BA, if you really do drop a line to David, can you tell him that he made a little arithmetic mistake? There’s no comment link on the planetary blog.

    Quote: “at about eight million kilometers (about eight times further than the Moon).”

    8 million km is more like 21 times the distance from the Earth to the Moon.

  8. Yeah, David did a good job on that blog.

    After Neil Tyson did some at the beginning of August, I wrote him and suggested he start a blog, since he was so eloquent on the Planetary Soc. one. I never heard from him though.

  9. Troy

    I was aware that Titan was picked instead of Pluto. If as “Pale Blue Dot” lamented there had only been a break in the clouds at Titan, it probably would have been worth it; Titan is much more interesting than Pluto. A previously blog reply (Andy with Titan+Neptune+Uranus > Pluto) is incorrect Voyager 1 would have went to Pluto, Voyager 2 would have still went to Uranus and Neptune. I would have chosen Pluto, though at the time Saturn and Titan were exciting enough prospects and Pluto like Uranus and Neptune would only be part of an extended mission. Another thing I wonder if the BA (and others) recall is that Voyager 2 was launched first, but on a slower trajectory.
    I also would read David’s blog, JPL is rather low profile which is unfortunate, unmanned missions are exciting maybe if more of them would speak up people would see they are manned after all. (Nowadays we only get to know the astronauts when the fall down while reassimilating to Earth’s gravity anyway)
    I think The Planetary Society still has David Doody’s series on planetary spaceflight, he is another David who works on Cassini (alas too many Daves in the world) I’ll recommend that for those who want more. An excellent series, breaks it down very nicely.

  10. mungascr

    New Horizons – launched this year to a planet.

    Arrives July 2015 at a dwarf planet .. or will the IAU decision have been reversed by then.

    Given the choice I’d love to have it all but if I had to choose at the time .. I’d have done what they chose – Neptune & Ouranos over Pluto – yep.

    Titan versus Pluto? A close one there -with Pluto you get a large exotic object with a moon into the bargain – or, as we know now, three moons an atmosphere and more. A complex intriguing little world with a lot of interest of its own. With Titan we get exotic alien yet earth-like world with a dense atmosphere & also lots that calls for attention. Tough one. If we’d known in advance Titan’s orange shroud would hide it’s surface as well as Venus’ then I’d opt for Pluto instead .. If not well its a coin-toss decison! 😉

    If I’d my ideal pick though – with full hindsight – I’d select Neptune and Pluto – & Titan too leaving bland Ouranos out of the tour.

    Of course that’s with hindsight ..

  11. Philip

    I remember hearing Ian Axford ( discuss the decision to send Voyager 1 to Titan rather than Pluto, which apparently he had some involvement with. He thought that in hindsight the decision was the wrong one and attributed it largely to Carl Sagan’s insistence that they had to go to Titan because of his “evolutionary theories”.


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