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Aerospace SpaceX: Another Falcon 9 ground pad landing

  1. Jul 18, 2016 #1

    mfb

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    Second attempt on land today, second success: A Falcon 9 delivered a Dragon capsule on its way to the ISS, and the first stage returned to the launch site and landed.

    Track record for the "Full Thrust" version so far:
    2 out of 2 landings on ground successful
    3 out of 5 landings on sea successful. One failure came from imprecise timing of thrust, one from an engine that performed worse than expected ran out of oxygen.

    SpaceX plans to re-launch a stage (the second one that landed) around September, just two months away. Payload is not fixed yet, at least not made public. SES, a communication satellite operator, is interested, and there is an SES flight scheduled for September and also one for October.

    Two more launches are planned for August, but it is unclear if those plans are still up to date. SpaceX frequently shifts launches back over time. In December, or early 2017, we might see the first Falcon Heavy launch and a demonstration launch (abort test) for the Dragon 2 capsule, which is designed for manned missions.
     
    Last edited: Jul 18, 2016
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  3. Jul 18, 2016 #2

    Jonathan Scott

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    I thought that was the initial conclusion but Elon Musk later corrected it to "Looks like early liquid oxygen depletion caused engine shutdown just above the deck". I seem to remember having seen some later analysis which said that automatic mixture adjustment had for some reason switched to a slightly more oxygen-rich ratio than usual, which resulted in it running out a little earlier than originally expected, but I can't find that right now - anyone know where that appeared?
     
  4. Jul 18, 2016 #3

    mfb

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    You are right. Well technically zero thrust is "worse than expected" I guess.
     
  5. Jul 18, 2016 #4

    Jonathan Scott

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    From some Googling, I think I'm probably confusing the oxygen-rich explanation with two other cases:
    1. A recent ULA Atlas 5 problem where the first stage cut off early because of oxidiser depletion and the second stage was barely able to correct for it.
    2. A previous SpaceX problem around 2010 where fuel ran out just before oxygen, risking damage through an oxygen-rich spike causing elevated engine temperatures.

    So the "liquid oxygen depletion" in the SpaceX case was probably simply a case of not quite having enough left by a tiny and unpredictable margin.
     
  6. Jul 18, 2016 #5
    I love that SpaceX has been so open with both their successes and failures. It's been a real treat watching them improve incrementally and I applaud both their audacity and tenacity.
     
  7. Jul 18, 2016 #6

    1oldman2

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    Good to see the IDA2 made into orbit. :smile:
     
  8. Jul 19, 2016 #7
    This fifth recovered booster fills their storage hanger. They need to find another one.
    They are also looking for two more landing pads - so they can land three boosters simultaneously.

    Actually, I thought this last mission was more interesting because of the ISS docking adapter it carried. They lost the first one June 2015. It would have been bad news if they had lost this one as well.
     
  9. Jul 19, 2016 #8

    mfb

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    As far as I know two boosters got moved out. One is supposed to stay somewhere for display, not sure about the other one. But that tweet is not so far off - they either have to start launching re-used boosters in a rapid rate, or find some other place to put them.
     
  10. Jul 19, 2016 #9

    Jonathan Scott

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    Just to be clear, this is for Falcon Heavy which is effectively three Falcon 9 boosters strapped together in a row, so from a single launch there would be three separate boosters coming back.
     
  11. Jul 19, 2016 #10

    1oldman2

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    One goes on display at headquarters in Hawthorne California, the other is being studied for damage, I believe in Texas.
     
  12. Jul 19, 2016 #11

    1oldman2

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    I believe the core stage has to do a barge landing, the boosters fly back to land.
     
  13. Jul 19, 2016 #12

    Jonathan Scott

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    The side boosters certainly get to go home early, but I think there's a hope that the core stage may sometimes be able to fly back too.
     
  14. Jul 19, 2016 #13

    mfb

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    It will depend on the mission. The Falcon Heavy core stage will be faster and further downrange, so flying it back really lowers the payload capability. Still better than with a Falcon 9, but I think reflying the cores has to be very reliable to make that a good option.
     
  15. Jul 19, 2016 #14

    Jonathan Scott

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    I wonder if there will also be the opposite case, requiring three drone ships. I think the other GCU ship name from "Player of Games" seems to be "Flexible Demeanour", but there are some great names in "The State of the Art" such as "Funny, It Worked Last Time...", "Only Slightly Bent" and "Ultimate Ship The Second".
     
  16. Jul 19, 2016 #15

    1oldman2

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  17. Jul 19, 2016 #16
    Nice discussion and exciting news.

    Thanks everyone for your contributions.
     
  18. Jul 19, 2016 #17

    mheslep

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    Flying the booster "back" means back to the launch pad? With a "Still Love You" landing at sea, further downrange should simply mean the barge goes further downrange. Or eventually a ground landing in, say, the Canaries (~same latitude, 3857 miles downrange). No?
     
  19. Jul 19, 2016 #18
    Might work, and if that is achievable then West African countries, (and maybe Portugal), is possible.
     
  20. Jul 19, 2016 #19
    the satellites carried by the spaceX rockets , what do they do, that is -what commercial use ?
     
  21. Jul 20, 2016 #20
    It's a wide variety. The most recent one resupplied the International Space Station. They have also done communication and military satellites.
    Here is there mission list: http://www.spacex.com/missions
    You can do a Google on each one. For example, Google "Jason-3" and you'll discover it's an ocean surface topography survey.
     
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