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      CommentAuthoraber0der
    • CommentTimeJan 7th 2018
     
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      CommentAuthorpcstru
    • CommentTimeJan 9th 2018 edited
     
    Zuma lost?

    "According to one source, the payload fell back to Earth along with the spent upper stage of the Falcon 9 rocket."

    Which if true, sounds like a failure of the upper stage (or a catastrophic fail of the payload). Bad news if it is the upper stage :

    "This was just SpaceX's third national security mission and was seen as critically important in winning further lucrative business from the US Department of Defense."

    Space is difficult.
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    Perhaps the payload failed to separate from the upper stage. I don't know where that leaves the blame to fall - on SpaceX or N-G.
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      CommentAuthorpcstru
    • CommentTimeJan 9th 2018
     
    Posted By: Andrew PalfreymanPerhaps the payload failed to separate from the upper stage. I don't know where that leaves the blame to fall - on SpaceX or N-G.

    Space-X, because integration of the satellite with the upper stage and the release would be their job. However, that would seem at odds with the circumstances of both coming back down quickly. For release they would need to be in orbit so they should not return quickly unless deliberately de-orbited. If they made their orbit I'd have expected them to spend some time trying to release rather than turn it around and de-orbit. So the most likely explanation is that they never made it to their orbit (assuming that the report is true).
    • CommentAuthorloreman
    • CommentTimeJan 9th 2018
     
    Billions of dollars up in smoke
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      CommentAuthorpcstru
    • CommentTimeJan 9th 2018 edited
     
    Posted By: pcstru
    Posted By: Andrew PalfreymanPerhaps the payload failed to separate from the upper stage. I don't know where that leaves the blame to fall - on SpaceX or N-G.

    Space-X, because integration of the satellite with the upper stage and the release would be their job.

    Actually, not true. Both the payload and the payload adapter which contains the separation mechanism were built by Northrop Grumman. So much secrecy surrounded the launch that I suspect the payload was Trumps tax returns.
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      CommentAuthorDuracell
    • CommentTimeJan 9th 2018
     
    Posted By: pcstruI suspect the payload was Trumps tax returns
    Ah, that might explain it then, because those tax returns seem to exist in something similar to a state of quantum uncertainty whereby they can be whatever anyone needs them to be right up until the moment they are disclosed ...
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    Preliminary indications from the opened FusionGPS report today suggest, from analysis of some Trumpian tax documents, that he's nowhere close to being a billionaire. Mind you, who would believe what Trump had people put on a form?
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    Fuel for the coming exoplanet bonanza
    https://www.centauri-dreams.org/?p=39095
    Polishing to 10% of a quarter wavelength is nice to have (15 nm)
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    An instantaneous power output of 1034 Watts is not too shabby!
    https://www.centauri-dreams.org/?p=39101
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      CommentAuthorAngus
    • CommentTimeJan 10th 2018
     
    Isotropic?
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    That's a good question. I took the quoted millisecond-to-day ratio and scaled the Sun's continuous isotropic output by that amount. Whether FRBs are beamed isn't something I know.
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      CommentAuthorAngus
    • CommentTimeJan 11th 2018
     
    Nor does anybody, I think.
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    I do.
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    He knows, you know
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      CommentAuthorTrim
    • CommentTimeJan 13th 2018
     
    Posted By: Andrew PalfreymanCelestial GPS using pulsars
    https://www.nature.com/articles/d41586-018-00478-8


    Great idea.
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    Even though I've helped design a few position triangulation systems, I am failing to understand this technique. Can anyone enlighten me on how it actually works? The relevant papers are Sheikh (2005) and Vidal (2017)
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      CommentAuthorAngus
    • CommentTimeJan 24th 2018
     
    Isn't it fairly simple - or am I missing something. I assume that if you know the relative phases of at least four remote oscillators, distributed in, say, a tetragon, then you can find your position in the tetragon to be one of some set of points. As you add more oscillators, the number of points within the volume that would yield a solution is reduced.

    Shirley.

    But it doesn't seem obvious to me that this would be a method for long range navigation.Was that what you meant?