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SpaceX Falcon 9 v1.1 launch - DSCOVR satellite

Discussion in 'SpaceX' started by Grendal, Feb 1, 2015.

  1. Grendal

    Grendal Active Member

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    #1 Grendal, Feb 1, 2015
    Last edited: Feb 1, 2015
    Starting the thread for the upcoming launch. There will be another attempt at landing the first stage. It's been mentioned in other threads that this one, because of the angle will be more difficult than the last attempt.

    The launch of DSCVR on Feb. 8, has a scheduled liftoff time of 6:10 p.m. EST (2310 GMT), with a backup launch date of Feb. 9 at 6:07 p.m. EST (2307 GMT). This flight will mark the second launch for SpaceX in 2015.

    The static test was completed successfully:

    SpaceX successfully conducts static fire test in preparation for DSCOVR launch - SpaceFlight Insider
     
  2. Danal

    Danal electricmotorglider.com

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    As of the moment of this post, the launch schedule is:

    The Deep Space Climate Observatory (DSCOVR) is scheduled to launch at 6:10 p.m. EST Sunday, Feb. 8 from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida on a SpaceX Falcon 9 rocket. A backup launch opportunity is available at 6:07 p.m. on Feb. 9, if needed.

    NASA Television coverage of the launch will begin at 3:30 p.m. In addition to launch coverage, NASA TV also will air a prelaunch news conference at 1 p.m. Saturday, Feb. 7.
     
  3. hockeythug

    hockeythug Active Member

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    Really excited for this.
     
  4. Auzie

    Auzie Tree Hugger Member

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    Aaah can't wait

    Started as a dream and a myth
    IcarusFlying.jpg

    Now reality
    Falcon9.jpg
     
  5. MacroP

    MacroP Member

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    With a sunset time of around 6pm it looks like the launch (and landing) is going to have spectacular backdrop. Can't wait.

    PS. What it the stage's return time? Around 15minutes?
     
  6. hockeythug

    hockeythug Active Member

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    #6 hockeythug, Feb 6, 2015
    Last edited: Feb 6, 2015
    On the last launch, CRS-5, 1st stage seperation was like at T+2:25 so prolly a little sooner than that.
     
  7. AudubonB

    AudubonB Mild-mannered Moderator Lord Vetinari*

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  8. Kalud

    Kalud Member

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    Pretty cool artist impression from the Business Insider article

    Image credits: Jon Ross at @zlsadesign and zlsa.github.io

    barge-landed-1920-1080.png
     
  9. c041v

    c041v Member

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    Does anybody know what they use guide the returned stage? If I recall correctly, GPS is only accurate to a few meters and even then, it's not terribly trustworthy when it comes to elevation.

    Are they using some combination of GPS/Proximity sensors and instrument guidance? I'd put this on par with landing the X-47B landing on an aircraft carrier, but I read that it actually aborted an attempt once when one of the navigational computers produced an error. That isn't exactly an option for SpaceX, so they must be using some sort of system that is a whole lot less susceptible to failure.
     
  10. hockeythug

    hockeythug Active Member

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    Could be wrong but I think I read that they use some sort of radar system.
     
  11. roblab

    roblab Active Member

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    As owner/operator of a Phantom II drone, which uses GPS, I would say that a meter is pretty good for such a large object as the returned stage. My drone can and does return by GPS if it loses signal from me, and lands gently at the same spot it left (+/- a foot or so). It will sit in space where ever I put it, move to where ever I want it, within a foot or so, and stay there. It's pretty amazing software, with gyros, etc., on a tiny chip. I bet they have better software than I do. I also know that military GPS is MUCH more accurate than that used by the public. Perhaps they are allowed to use it.

    The newer drones which can be used indoors without GPS, rely on bi-optical cameras that "see" the floor and land gently. I believe that the rocket stages have cameras on them already.

    Doesn't sound like a problem.
     
  12. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Is that still true? I thought I'd read a few years ago where they removed the restriction. (not to say that there isn't a new mil-spec with more accuracy).
     
  13. physicsfita

    physicsfita Member

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    Selective Availability was turned off May 2000. Officially, there is no intention to reinstate it: GPS.gov: Selective Availability
     
  14. ggr

    ggr Roadster R80 537, SigS P85 29

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    There is an enhancement to GPS called "WAAS" (Wide Area Augmentation System), in which a ground-based system (in a very well surveyed place) transmits corrections to the GPS signals to compensate for the inaccuracies that are mostly atmospheric and ionic in origin. This is used by receivers in aircraft, for precision landings, for example.

    The biggest problem with GPS (even with WAAS) is that it is quite inaccurate in the vertical direction. I believe the Falcon 9 uses a radar altimeter both for accurate altitude information and also partly to locate the barge (which is hopefully higher than the sea around it).
     
  15. mdevp

    mdevp Member

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    Approximately how long after launch is the first stage expected to land on the platform?
     
  16. FredTMC

    FredTMC Model S VIN #4925

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    From my memory it was about 30-45 min after launch
     
  17. snellenr

    snellenr Member

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    First stage landing attempt occurs roughly 10 minutes after launch. Live coverage stays with the second stage burn -- there won't be any live coverage from the barge, but news of success/failure has been pretty quick.
     
  18. Pricee2

    Pricee2 Member

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    www.spaceflightnow.com says T+0:09:00 for 1st stage landing. It will take some additional time to find out the results of the landing attempt.

    snellenr beat me to it!

    I am waiting for the countdown time video to start.
     
  19. mkjayakumar

    mkjayakumar Active Member

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    If we can live feed from within the rocket fuel tank, I don't understand what is the difficulty in having live coverage from a ship a mile or two from the barge.
     
  20. Dave46

    Dave46 Member

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    #20 Dave46, Feb 7, 2015
    Last edited: Feb 7, 2015
    SpaceX is probably using avionics systems similar to autolanding aircraft + airports: differential GPS from the barge aka ASDS + radio altimeter (radar) + triple redundant fail operative flight control computers. That capability has been around for over 2 decades.
    And BTW the accuracy can be 10 to 20 cm ! in best case which is about 10x better than they need.
     

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