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SpaceX's Grasshopper VTVL takes a 40 meter hop

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    #122
    thecommander
    Registered Users Posts: 2,537 ✭✭✭thecommander


    Some images Musk released on Twitter. So close to the landing, but fins gave out at last minute.

    7sUwcIK.jpg

    kKCr4K4.jpg

    qEsgfnw.jpg

    LrwWSd5.jpg


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    #123
    nokia69
    Closed Accounts Posts: 2,050 ✭✭✭nokia69


    would love to see the videos

    the 29th can't come fast enough

    I don't think the fins are much help close to the pad, I think they do most of their work higher up where the speed is greater


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    #124
    thecommander
    Registered Users Posts: 2,537 ✭✭✭thecommander


    Video.

    https://vine.co/v/OjqeYWWpVWK


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    #125
    Hmmzis
    Registered Users Posts: 2,004 ✭✭✭Hmmzis


    Deeem, that's close.

    Also, the explosion is awesome, can't stop watching the video :D


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    #126
    shedweller
    Closed Accounts Posts: 4,029 ✭✭✭shedweller


    Hmmzis wrote: »
    Deeem, that's close.

    Also, the explosion is awesome, can't stop watching the video :D
    It fairly chucked the top overboard eh?!
    One thing thats bothering me. It was coming down very fast and how much of this is due to the loss of steering?
    Because if it was doing that speed in an upright position it would have ended badly anyway.
    They've done this on dry land anyway so im confident for the next effort.
    We need more of this awesomeness!


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    #127
    thecommander
    Registered Users Posts: 2,537 ✭✭✭thecommander


    shedweller wrote: »
    It fairly chucked the top overboard eh?!
    One thing thats bothering me. It was coming down very fast and how much of this is due to the loss of steering?
    Because if it was doing that speed in an upright position it would have ended badly anyway.
    They've done this on dry land anyway so im confident for the next effort.
    We need more of this awesomeness!

    It's like when you balance a brush handle on your hand, once you go beyond a certain point of it tipping it's gone. Combine that with engines that are still lit and it will accelerate in that direction. I think the speed was fine, just the tipping threw it. We'll see next time.


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    #128
    The One Doctor
    Registered Users Posts: 2,339 ✭✭✭The One Doctor


    Does SpaceX user vernier engines for landing the first stage? It'd save them a lot of faffing around if not.


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    #129
    shedweller
    Closed Accounts Posts: 4,029 ✭✭✭shedweller


    Now that i have looked at it again it does look like its coming towards the camera which would explain its high vertical speed.
    They better do the next one in daylight and with a handful of go-pros!


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    #130
    nokia69
    Closed Accounts Posts: 2,050 ✭✭✭nokia69


    shedweller wrote: »
    It fairly chucked the top overboard eh?!
    One thing thats bothering me. It was coming down very fast and how much of this is due to the loss of steering?
    Because if it was doing that speed in an upright position it would have ended badly anyway.
    They've done this on dry land anyway so im confident for the next effort.
    We need more of this awesomeness!

    my guess is that when they lose the fins, the engine had to over compensate during the last burn


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    #131
    nokia69
    Closed Accounts Posts: 2,050 ✭✭✭nokia69


    The One Doctor wrote: »
    Does SpaceX user vernier engines for landing the first stage? It'd save them a lot of faffing around if not.

    cold gas trusters AFAIK


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    #132
    Hmmzis
    Registered Users Posts: 2,004 ✭✭✭Hmmzis


    shedweller wrote: »
    It fairly chucked the top overboard eh?!
    One thing thats bothering me. It was coming down very fast and how much of this is due to the loss of steering?
    Because if it was doing that speed in an upright position it would have ended badly anyway.
    They've done this on dry land anyway so im confident for the next effort.
    We need more of this awesomeness!

    It certainly solves the mystery of the missing bits (well, most of the stage actually). If the hydraulics failed with a minute to go then that's fairly high up still. The gimball of the engine apparently wasn't enough to balance out the stage. My understanding is that only a very limited deviation from vertical can be controlled by gimballing engines without adding excessive horizontal velocity.


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    #133
    thecommander
    Registered Users Posts: 2,537 ✭✭✭thecommander


    The One Doctor wrote: »
    Does SpaceX user vernier engines for landing the first stage? It'd save them a lot of faffing around if not.

    No need for them, would add far too much weight swell. They've shown with the grasshopper tests and CRS5 landing that they can get to a point without them. Not enough hydraulic fluid was the problem, once they have enough I'd be certain enough they'll land it (unless some unknown issue arises)


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    #134
    shedweller
    Closed Accounts Posts: 4,029 ✭✭✭shedweller


    I was just thinking. The extra hydraulic fluid is going to weigh more. How would it compare to having a return line to the hydraulic pump and reuse a smaller amount of hydraulic fluid? Like a normal hydraulic system.
    Ok, this would require an in depth knowlege of the rocket to give a definite answer but still, there's some merit in that surely?
    And i know there would have to be extensive re-testing done. But it would mean the controls will stay working no matter what.
    Anyway, i had to ask. I dont like seeing machines breaking down!


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    #135
    thecommander
    Registered Users Posts: 2,537 ✭✭✭thecommander


    shedweller wrote: »
    I was just thinking. The extra hydraulic fluid is going to weigh more. How would it compare to having a return line to the hydraulic pump and reuse a smaller amount of hydraulic fluid? Like a normal hydraulic system.
    Ok, this would require an in depth knowlege of the rocket to give a definite answer but still, there's some merit in that surely?
    And i know there would have to be extensive re-testing done. But it would mean the controls will stay working no matter what.
    Anyway, i had to ask. I dont like seeing machines breaking down!

    If you have a closed loop you need pumps which add weight and complexity. They use pressurised gas to pump the fluid out, seems to be a case of just adding more fluid (and more gas I guess)


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    #136
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,814 Mod ✭✭✭✭Capt'n Midnight


    thecommander wrote: »
    If you have a closed loop you need pumps which add weight and complexity. They use pressurised gas to pump the fluid out, seems to be a case of just adding more fluid (and more gas I guess)
    Actually it's cleverer than that they reuse the fluid in the engines because it's fuel.

    There's a lot to be said for using simple reliable systems even if they are slightly heavier. Complexity adds risk. And given the % of spaceflight failures shaving off too much weight on stage 1 is just asking for trouble.

    http://space.stackexchange.com/questions/7771/why-does-the-falcon-9-consume-hydraulic-fluid
    Falcon 9 uses an open hydraulic system that has a separate tank of RP-1 (which is used as the hydraulic fluid) pressurized by Nitrogen near the interstage, which, after use, drains down back into the main RP-1 tank for "reuse" by the engines. There are a variety of reasons that SpaceX made decisions to use this design:


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    #137
    shedweller
    Closed Accounts Posts: 4,029 ✭✭✭shedweller


    I must humbly hang my head in shame for not thinking of that...
    D'oh!


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    #138
    thecommander
    Registered Users Posts: 2,537 ✭✭✭thecommander


    Capt'n Midnight wrote: »
    Complexity adds risk.

    Exactly. So don't use more pumps.


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    #139
    irishgeo
    Registered Users Posts: 9,387 ✭✭✭irishgeo


    Is it supposed to land on the barge horizontal or vertical.


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    #140
    shedweller
    Closed Accounts Posts: 4,029 ✭✭✭shedweller


    irishgeo wrote: »
    Is it supposed to land on the barge horizontal or vertical.

    Vertical. Wouldnt want to be much swell in the sea when it lands!


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    #141
    _Jumper_
    Closed Accounts Posts: 150 ✭✭_Jumper_


    Google and Fidelity Investments have bought just shy of 10% of SpaceX, plan to pump money into helping it develop Satellite Internet for undeveloped/underserved regions around the world or in Musks case, beginnings of Internet for Mars Colony.

    Values SpaceX at 10 Bil Dollars.

    Valuations be crazy.


    What would be a good name? Hmm, Trans Net?


    gigaom.com/2015/01/19/elon-musks-satellite-plan-project-loon-without-helium-or-latency/

    bloomberg.com/news/2015-01-20/musk-s-spacex-sells-10-stake-to-google-fidelity-for-1-billion.html?hootPostID=e032d9a22131660ad2c3ecfaa1639a46


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    #142
    nokia69
    Closed Accounts Posts: 2,050 ✭✭✭nokia69




    can't wait to see this badboy fly


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    #143
    nokia69
    Closed Accounts Posts: 2,050 ✭✭✭nokia69


    http://en.wikipedia.org/wiki/Deep_Space_Climate_Observatory

    possible spaceX launch tonight, just after 11

    they will also try first stage recovery again but it will be harder than the ISS missions, so who knows if it will work

    you can watch it at http://www.spacex.com/webcast/


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    #144
    thecommander
    Registered Users Posts: 2,537 ✭✭✭thecommander


    Tomorrow so!


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    #145
    MayoForSam
    Registered Users Posts: 2,266 ✭✭✭MayoForSam


    Now happening at 10:45pm tonight (live webcast).


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    #146
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,814 Mod ✭✭✭✭Capt'n Midnight


    now showing live feed


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    #147
    greedygoblin
    Registered Users Posts: 1,649 ✭✭✭greedygoblin


    No go? :(


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    #148
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,814 Mod ✭✭✭✭Capt'n Midnight


    high altitude winds so tune in again tomorrow at 23:00


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    #149
    Hmmzis
    Registered Users Posts: 2,004 ✭✭✭Hmmzis


    aaand it's a scrub - 151% violation of high altitude winds if I heard the comms right.


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    #150
    Knifey Spoony
    Registered Users Posts: 1,557 ✭✭✭Knifey Spoony


    Looks like they won't be attempting recovery of the first stage using the drone ship due to weather in the Atlantic. :(

    There'll be a soft landing in the water instead.

    http://www.spacex.com/press/2015/02/11/dscovr-launch-update


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    #151
    nokia69
    Closed Accounts Posts: 2,050 ✭✭✭nokia69




    falcon 9 first stage on the road to the cape, might be for CRS 6


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