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Voyager 1 and Voyager 2 - Wow!

  1. Dec 11, 2012 #1
    Hi there. Just been reading about Voyager 1 and it's current progress. Wow. Totally incredible. I mean this is seriously a contender for mankind's greatest feat of science and engineering, isn't it?


    I want to read more and in a book - not on the internet.

    Can anyone recommend a good book about the Voyager missions?

    I have tried searching the web for "Voyager Books" but I keep getting loads of Star Trek stuff which would be an equally amazing feat of human engineering if it wasn't science fiction.

  2. jcsd
  3. Dec 11, 2012 #2
    Can't help you with the book but it always amuses me to think that an average iPhone has more computing power than the voyager.
    The rapid technological progress of mankind never seizes to amaze me.

    When I was a kid we had VHS tapes now I hardly even see DVD:s anymore!
  4. Dec 11, 2012 #3


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  5. Dec 12, 2012 #4
    But how about the power supply capacity? :smile:
  6. Dec 12, 2012 #5
    I have the following books on Voyager and would find it difficult to choose between them. I think you would enjoy both.

    Henry C. Dethloff and Ronald A. Schorn "Voyager's Grand Tour: To the Outer Planets and Beyond" Konecky & Konecky 2009 ISBN:978-1-56852-715-4

    Stephen J. Pyne "Voyager: Seeking Newer Worlds in the Third Great Age of Discovery" Viking 2010 ISBN:978-0-670-02183-3

    This one looks at the Voyagers and other robotic craft used for planetary exploration. I haven't got round to reading it yet:
    Michel van Pelt "Space Invaders: How Robotic Spacecraft Explore the Solar System" 2006 Springer ISBN:978-0387332321

    All of these are available second hand, online, for a few pounds. I find Abe Books is a good source.

    I would also recommend you look at Enclyopedia Astronautica and, as Drakkith suggested, the NASA sites.

    Oh, and for an excellent work on space exploration in general this one is first rate:

    William Burrows "This New Ocean: The Story of the First Space Age" Random House 1998 ISBN: 0-679-44521-8
  7. Dec 12, 2012 #6
    Excellent. Thanks for the recommendations.
  8. Dec 13, 2012 #7


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    "Murmers of Earth" by Carl Sagan, FD Drake, Ann Druyan, Timothy Ferris, Jon Lomberg, and Linda Salzman Sagan for a slightly different slant.

    It's a book about the making of "The Golden Record", which travels aboard the Voyager spacecraft. The chapter by FD Drake on the best way to create a message that could be understood by a completely alien race was fascinating.

    And the story of the pictures was kind of interesting - especially the concern by a late 70's government over whether we should be putting nude pictures of humans on the record without blacking out the genitalia.

    And the story behind the story? Linda Salzman Sagan was Carl Sagan's wife, while Ann Druyan was his lover (and future wife). Ann Druyan had her brain waves recorded and thought about Carl during the recording. That way, if aliens find the spacecraft and are able to decipher the brain waves, they'll know what love is. That part obviously didn't make into the book - it wouldn't have been very prudent since Linda didn't know about Carl and Ann .... yet.
    Last edited: Dec 13, 2012
  9. Jan 2, 2013 #8
    Think how much our technology has advanced sinse the launch of the voyager(s). Imagine if a more advanced species did something similar. We would come across their technology and be like WOW... only for that peice of technology to be potentially thousands of years outdated to them.

    I really hope aliens are discovered before I leave this earth =(
  10. Jan 14, 2013 #9


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  11. Feb 5, 2013 #10
    Too bad Voyager will end up trapped in some orbit at best at some point or smashed.
  12. Feb 5, 2013 #11


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  13. Feb 5, 2013 #12
    Trapped in some orbit? What orbit are you thinking about? It is going faster than Sol's escape velocity and will continue out into interstellar space and the likelihood of it getting hit is pretty remote. Remember, it has been going on for decades now and nothing has stopped it yet and likely nothing will since the density of objects is greatly reduced when you get into interstellar space so if it hits anything or gets captured by a star it will be tens of thousands of years from now.
  14. Feb 5, 2013 #13


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    I'm with Drakkith on this one ... what are you talking about?
  15. Feb 6, 2013 #14
    Just imagine it gets close to a large object, like another star system, or a large rock, how is it supposed to escape again?
  16. Feb 6, 2013 #15


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    It would seem that you underestimate just how big space is and how few things there are in it, on average.
  17. Feb 6, 2013 #16


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    Unless it encounters a specific set of circumstances that allow it to lose kinetic energy, it will not be captured. This is because as it approaches a massive object it picks up speed, only to lose the same amount of speed as it recedes from it, ending up at the same speed it was at only it is now at a different trajectory.
  18. Feb 8, 2013 #17
    It might crash into it and that would be the end of it but if it doesn't have an atmosphere and it just goes by the surface it will be going too fast to become a satellite, just change directions and end up going to some random angle off again.

    You need to study just what it takes to capture an object to be a satellite. If you know the orbital velocity of a planet, multiply it by the square root of two and you know the escape velocity. Now if you want to be captured by a planet you first need to be going slower than escape velocity or its a no go, goodbye planet. So you first need to slow down to less than the escape velocity at whatever altitude you pass by. Then you need to slow down even more by that same factor, square root of two, to be captured. How do you suppose all that is going to happen to a non-powered space probe flying through space? The only possible way would be if the planet had an atmosphere and you use aerobraking but that is not going to happen to a random probe passing at a random altitude and random velocity, most certainly faster than the escape velocity of said planet.

    It takes very detailed calculations to safely be captured via aerobraking, there would have to be a computer onboard with sensors like radar or lidar or some such to track the probe every second of the encounter and a means to slow down first to make aerobraking even work.

    Then you have to know just how fast you can dip into the atmosphere and just how long to keep from burning up, slowing down a bit after each dip into the atmosphere and so forth.

    This is an active system and is used by the space shuttle, mars probes and such but has to be very carefully planned.

    You are not going to even get close to pulling that off by a random dead probe passing by a random planet with or without an atmosphere, which would happen to the Voyagers for literally millions of years anyway. It could probably go a billion years before anything like that would happen.

    It's a vast empty space between the stars.
  19. Feb 8, 2013 #18


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    We have ~10000 stars closer than 100 light years, giving an estimated star density of 0.0024 stars per cubic light year. As an upper estimate, I'll use 0.01~1/125 here. Few stars have a radius larger than ~750 times the solar radius (500 million km), so this is a very generous upper estimate for a typical star. It also accounts for the gravitational attraction, which increases the impact probability. Planets and other massive objects are completely negligible here. With those numbers, we have (on average) one star with a radius of 500million km in every cube with a side-length of 5 light years. This star occupies a fraction of 3.5*10-10, leading to a mean free path length of 14 billion light years, assuming the Voyager probes stay in a region with similar stellar density (they should orbit the galactic center in a roughly circular orbit like our sun). With a relative velocity of ~50km/s, this leads to a mean "lifetime" of ~1014 years, or about 6000 times the current age of the universe.

    The Voyager probes will see all sorts of decay due to radiation, dust and so on - but they will not collide with any massive object within any reasonable timescale and probability, assuming they are not captured on purpose.
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