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Project Orion again - why not interstellar probe?

  1. Feb 13, 2016 #1
    I was watching recently that PBS Space Video on youtube about space propulsion and it got me thinking about Project Orion again.

    They talk about sending humans to another star system, but would it not be spectacular enough to send probe? The probe could scan and photograph planets there and maybe we could learn lots of stuff or are telescopes enough? This spaceship could bring with it lots of equipment since it can be massive.

    They say how it would take 90 years to arrive to closest star, but that's with people in it, maybe the probe doesn't need to brake but use all the nukes to speed up, then it would be there in 45 years and we would get data sooner if it had some nice telescopes to look ahead. Maybe it could even launch smaller probes to orbit those planets but then it would be the problem of communication since they would have to transmit data to Orion first and if it's not stooping there wouldn't be much time.
    But maybe since it doesn't carry people it could accelerate faster, meaning that it could use bigger and fewer bombs and therefore have enough to stop?

    When it comes to fallout the Orion could be launched over the North Pole where the field lines go straight out, and use very unsymmetrical bombs so you can be sure the debris is going outwards and not inwards. To soften this even further neutron bombs could be used since they produce neutrons without fission, and neutrons you could easily absorb. That would have meant killing one person per mission - but is that acceptable that someone must die?

    Of course the question of politics and "do we really need this?" Could NASA, ESA and China work together in making this? Would this be a good idea? Would it not bring precious data?
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  3. Feb 13, 2016 #2


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    The time would not half.
    It is quite pointless to gather data from more than a light month away (~1 year before the fly-by) - telescopes on Earth would easily get a better resolution as their distance is just ~50 times larger.
    Momentum conservation - spacecraft goes up, bomb material has to go down. The magnetic field lines don't matter, wind will transport the debris around.

    There are various technical challenges of such a mission - the Wikipedia article has a long list. The political challenges are massive as well. And there is also the Wait calculation: sending a faster spacecraft later could give you the data faster. Or just wait for a few more decades of telescope development on Earth.

    It is probably not impossible, but it would need a huge amount of money, political problems, radiation problems, and (even if it works) just produce a few images in the distant future.
  4. Feb 13, 2016 #3

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    And that is the key question. If you are going to spend a trillion dollars on this effort, what are you going to learn? And could you learn more by doing this some other way?
  5. Feb 14, 2016 #4
    What about electricity on board? Let's say someone decides to make it how would you power computers on it for 50 years or even hundred?
  6. Feb 16, 2016 #5
    I did a little research and it seems Traveling wave reactor (TWR) could be used to harness electricity. TWR design is good to go without refueling for about 60+ years, so you would have to bring back-ups if you wanted more time.

    Well the calculation already reefers to the scenario if all debris were spread around the world. I was also reading on Wikipedia about how relatively clean PNEs (Peaceful nuclear explosions) could be used, they are bombs that yield 98% fusion and have been tested by US and former USSR in 1970s, so maybe it could be cleaner.
    OK let's tackle the learning part. I'm not quite sure how good the future telescopes will be, but I still think that closer look always yields more knowledge. I mean just look what spectacular knowledge we got from probes in our own sol in just past few years. Like that Ceres and Vespa seem to have steam coming from them. Or that Pluto does not have as much craters as it was expected and even seems to have pools of liquids - on some "little boring rock". Or look few decades ago when it was thought that all moons in solar system will be same "boring" moons like ours until probes scanned them. Now, of course, we have telescopes that we can see geysers Enceladus, but will the future telescopes give us something even close to that when it comes to extra-solar planets? Because I also think that for every extra-solar planet that we discover we have only the knowledge of our own planets to compare to. I mean if the probe comes there and discovers nothing more unusual in those extra-solar planets then we expected, then fine, we win again because we're as smart as we thought and let's face it many many times in the history of humans we fell into the trap of thinking that we already got figured out how things work in the universe.
    Even the journey itself can teach us a lot. Remember when Pioneer was leaving sol there was this unexpected anomaly or Pioneer effect, so just going there would be gaining knowledge.

    But of course the price. Now it seems there wasn't any serous study of how much this would cost and I think there should be at least a cost study. From what I can see in wikipedia article it doesn't look that it would be THAT expensive. I'm more inclined to believe maybe between 100 billion to 200 billion USD spread over something like 30 years and it certainly would have to be done internationally by US, EU, Russa and China and they have the money to pay, but of course it would be hard to convince people. Of course I could mention some much more expensive stuff that are currently going on that not only have no purpose but are also harmful, but would that matter?
    You could probably much easier talk China, Russia and EU into this project then United States. US would probably be the hardest one, but also the crucial.
  7. Feb 17, 2016 #6
    OK I think this is my last entry in this. Let's leave the political talk and what matters here is motivation. Because motivation can do wonders. What can be a motivation that will capture people's imagination?
    My guess one day when Earth-like planet is spied with the telescope and if it's somewhere in the vicinity of 20 ly then people will be eager to build this probe and send to that planet to see if it's still in dinosaur era or humanoid era. Especially after few more years of Star Wars movies. Can you imagine the space ship coming to the planet and discovering alien dinosaurs and then malfunctioning and falling down destroying alien dinosaurs?
  8. Feb 18, 2016 #7


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    or landing/crashing into an alien city (appearing as a bomb, so to speak). While we don't learn of this catastrophe for twenty years or so, they immediately mobilize to finish the WAR that we started!!! That is something to ponder.
    Or even just a likely, we inadvertently contact a fierce and hostile bunch who has a 20 year head start to prepare for a war we don't even realize we are in.
  9. Feb 18, 2016 #8


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    Any civilization that can spot a probe randomly flying through their planetary system, or identify the artificial nature of an (extremely unlikely) impact, can easily find Earth and probably detect signs of intelligent life there.
  10. Feb 21, 2016 #9
    t was my failed attempt to make a joke, associating it with our dinosaur period because as a child I remember reading a book on dinosaurs and in a text why they all died out was mentioned how there were bucketful of theories including one where Martians killed them. Of course if Orion came to another star system it would be empty of bombs by then.
    I also imagine Orion-like probe would consist of let's say dozen probes and it could launch and leave like one probe in the now mysterious Oort cloud, not to mention Orion would be the first to visit it and actually prove visually it's there and then entering other star's Oort cloud. It would be such an exciting wold to live in.
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