Tags:
  1. Mick West

    Mick West Administrator Staff Member

    20160724-113535-xkfoc.

    In a bit of recycled bunk, some video of the September 2nd, 2015 Atlas V Rocket Launch in Florida has popped up on social media wth misleading headlines. The footage was upload to Liveleak with the headline "Unkown object over Azerbaijan - July 2016" [sic] and also posted on the Facebook page of Bestagram Azerbaijan, where it got 15 million views. It was then picked up by British tabloid media, including the Daily Mail, and The Sun.

    The footage is in Miami airport, where several people took videos of the rocket launch, for example:

    Source: https://www.youtube.com/watch?v=LAugPb5GLWM


    And another:

    Source: https://www.youtube.com/watch?v=CEbl64L-wGk


    This video shows the full development of the plume:

    Source: https://www.youtube.com/watch?v=ZJ6LlShMZ8g


    Local News reported on the public's confusion:

    Source: https://www.youtube.com/watch?v=Yk6__3cpwCE


    And the day after the launch the Miami New Times reported "Everyone Freaked Out"
    http://www.miaminewtimes.com/news/a...p-miamis-sky-and-everyone-freaked-out-7867087
     
    Last edited: Jul 24, 2016
    • Like Like x 4
  2. Mackdog

    Mackdog Active Member

    Why is it going sideways? Or is it just so high up and following the curvature of the earth that it appears to be sideways?
     
  3. Mick West

    Mick West Administrator Staff Member

    It was launching MUOS-4 a geostationary satellite. It had to end up over the equator at 75° East, that's on the other side of the planet, so it can't just go straight up.
     
    • Informative Informative x 1
  4. sharpnfuzzy

    sharpnfuzzy Member

    You cannot orbit the earth by just going straight up. You need to go fast enough parallel to the surface so that you can continously fall but miss hitting it because it curves away from you too quickly.
     
    Last edited: Jul 24, 2016
  5. Mick West

    Mick West Administrator Staff Member

    This is a geosynchronous satellite though, so in theory it could go straight up if launched from the equator under the spot it wanted to end up at.

    You'd still need to speed up perpendicular to the Earth, but you could in theory rise up in a straight line.
     
  6. sharpnfuzzy

    sharpnfuzzy Member

    Good point. That's correct in theory.

    P.S. Meant parallel not perpendicular :)
     
  7. DougW

    DougW Member

    Yahoo home page (Australia) have regurgitated this video with a click bait heading. At least in the article it explains what it was.
     
    • Like Like x 1
  8. Hevach

    Hevach Senior Member

    No, you can't.

    Simplified description of what happens if you try:

    http://wiki.kerbalspaceprogram.com/wiki/Maneuver_node#Radial_and_anti-radial

    Radial/anti-radial burns (straight towards or away from the body you're orbiting) rotates the orbit around the craft (the link uses the example of spinning a hula hoop on a stick). If you burn directly upward from an orbital launch center, your orbit will be bringing you back to the launch point, which means a fiery reentry and crash. "Fiery reentry and crash" is the normal outcome of applying common sense to orbital mechanics.

    [​IMG]


    There's no cheat code for an orbit. To get a roughly circular orbit takes a second burn at apogee after launch, or our perigee will still be down near the launch center, which ends badly for you. Generally there's a two ways to get to geosynchronous orbit with the fewest steps (Delva-V is lowest from an equatorial launch, but you can't ignore steps):

    1. Launch to LEO, and continue the circularization burn until perigee rises above apogee, creating a new apogee at more-or-less the target altitude. Then at that apogee, a second circularization burn to raise perigee to the same altitude.

    2. With a larger launch vehicle, launch into an eccentric orbit with apogee at/near the target altitude, with a single circularization burn.


    Most of the time, method 1 is used, and the circularization burn and ascent burns aren't combined, because launch windows for earth orbit are more forgiving than ascent windows. Instead you'd park in a low orbit and then use two prograde burns (a Hohmann Transfer) to ascend to the target altitude.


    In theory you can do it all in one continuous burn. It's a complicated low-thrust burn, and it still follows the same profile with less distinct intermediate stops. It's still not a straight up point and shoot - that'll either put you in a heliocentric orbit or on a path to fiery reentry and crash.
     
    Last edited: Jul 25, 2016
  9. Mick West

    Mick West Administrator Staff Member

    I think you can, it's just not practical (and maybe impossible with mass reaction thrusters). I wasn't suggesting burning directly upwards, I was suggesting traveling directly upwards. You'd have to progressively vector the thrust sideways to maintain angular velocity (and hence increase orbital speed). I said "You'd still need to speed up perpendicular to the Earth" but should have said "perpendicular to the vertical vector" or just "sideways". I was imagining some theoretical craft with arbitrary vectoring capability, and unlimited thrust.

    Won't it bring you back towards the center of the earth? So you'll land somewhere behind the launch center?
     
  10. trevor

    trevor Active Member

    That's a cool sight. I've never seen anything like that before.
     
    Last edited by a moderator: Jul 26, 2016
  11. Astro

    Astro Member

    Since it was an early morning launch headed east, the rocket flew up into the sunlight while it was still quite dark out and twilight was only just beginning. This produced a spectacular view of the sunlit rocket plume, which isn't that common and no doubt contributed to people's confusion. It reaches line of sight to the sun right at about 3:18 in this video when you can suddenly see the plume start to light up:


    I also believe there's a sizable chunk of the general public who are under the mistaken impression that "NASA was shut down after the shuttle program" and that "NASA launched all the rockets at the Cape." Both are false; NASA is working toward a return to manned spaceflight launches both with the commercial crew and Orion vehicles (to say nothing of the unmanned missions and cargo resupply launches), and the US Air Force is in charge of overseeing a wide variety of unmanned launches from Cape Canaveral (carried out by a variety of operators including SpaceX, ULA, and soon Blue Origin as well). Nevertheless, I think there's still a significant misconception in the public that "NASA shut down." People are only just starting to become aware of how much activity is really going on out there, which is probably also why so many were surprised to hear the sonic booms from the last Falcon 9 landing and so many called 911.
    http://www.clickorlando.com/news/space-news/spacex-falcon-9-aims-to-launch-iss-cargo-land-at-cape

    That kind of activity will probably go a long way to changing the public's perception. Even if you weren't actively looking for it, you knew when the shuttle program was active thanks to those loud sonic booms. Even so, when you get as far from the Cape as Miami, there's not nearly as much attention paid to unmanned "routine" launches like this. Morning twilight launches put on a particularly beautiful spectacle that most people just don't expect; even some who were deliberately attending the launch were unaware of what was happening and thought the rocket was having a problem.
     
    • Like Like x 1
  12. Gorfintron

    Gorfintron New Member

    Mick, your post caught my eye because I've seen the same thing before. Then I looked back for it and realized it happened one month later, November, 2015, but on the west coast!
    http://www.cnn.com/2015/11/08/us/southern-california-navy-test-mystery-light/
     
    Last edited by a moderator: Jul 28, 2016
  13. scombrid

    scombrid Senior Member

    I was fortunate to be paddleboarding on the Indian River Lagoon for two of those pre-dawn launches last year. They were spectacular. I stopped my workout to watch both times.
     
  14. Psyringe

    Psyringe Banned Banned

    I'm glad this was debunked here, been explaining these away as NASA/Missile related due to location of the spottings.

    Although the government took credit for the missile over LA, as mentioned by
    Gorfintron.
    My source at first discovery;



    The Missile was a Trident launched via Submarine.
    There used to be video evidence of the credit claim; but I can't find it anymore. *facepalm*
    Getting to a point where you need to download this stuff every time first time.