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Space X

  • 30-03-2017 12:07pm
    #1
    Stan27
    Registered Users Posts: 528 ✭✭✭


    Huge space x fan.

    Launching first reusable first stage tonight. Anyone watching it ?
    Will be a live link on the space x website.


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Comments

  • #2
    Beeker
    Moderators, Science, Health & Environment Moderators Posts: 3,643 Mod ✭✭✭✭Beeker


    Stan27 wrote: »
    Huge space x fan.

    Launching first reusable first stage tonight. Anyone watching it ?
    Will be a live link on the space x website.

    I sure am, you can get good coverage at Spaceflight Now https://spaceflightnow.com/

    launch window opens at 23:27 Irish time tonight.


  • #3
    irishgeo
    Registered Users Posts: 9,368 ✭✭✭irishgeo


    Live here https://youtu.be/xsZSXav4wI8

    T - 8 mins


  • #4
    domrush
    Registered Users Posts: 1,186 ✭✭✭domrush


    Successful landing, fantastic science


  • #5
    domrush
    Registered Users Posts: 1,186 ✭✭✭domrush


    Delighted for Elon Musk what a journey


  • #6
    josip
    Registered Users Posts: 13,621 ✭✭✭✭josip


    What I find great about this is that it's not mainstream news and that the successful landing on the barge is a footnote in the Space X release.
    While Space will never be easy, some aspects are becoming more routine.


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  • #7
    Stan27
    Registered Users Posts: 528 ✭✭✭Stan27


    Great achievement. The company is only 15 years old, imagine what the next 15 will bring.


  • #8
    ricimaki
    Registered Users Posts: 650 ✭✭✭ricimaki


    https://twitter.com/elonmusk/status/847594208219336705

    Plans for a re-launch within 24 hours! We could be seeing launches several times a week in the next few years!


  • #9
    Stan27
    Registered Users Posts: 528 ✭✭✭Stan27


    ricimaki wrote: »
    https://twitter.com/elonmusk/status/847594208219336705

    Plans for a re-launch within 24 hours! We could be seeing launches several times a week in the next few years!


    I presume all the checks will be done by computers, if this will be achievable.


  • #10
    Beeker
    Moderators, Science, Health & Environment Moderators Posts: 3,643 Mod ✭✭✭✭Beeker


    Stan27 wrote: »
    I presume all the checks will be done by computers, if this will be achievable.

    They want the booster to be as reliable as an airline requiring only a quick visual check and connect it up to a computer to run a quick diagnostic then refuel and go again.


  • #11
    josip
    Registered Users Posts: 13,621 ✭✭✭✭josip


    My understanding is that the Falcon 9 will make up the first stage of the Falcon Heavy.

    The Falcon 9's final speed before turnaround and re-entry is 1.5km/s and it doesn't get far outside the atmosphere which means that knocking off enough of that speed before re-entry is manageable and viable.

    The SLS first stage however has a much higher delta-V and goes further so relanding that is seen a much more difficult proposition and the penalty of the amount of fuel required to slow it down isn't cost effective.

    I've just read however that Space X intend to return their Falcon Heavy 2nd stage.

    https://techcrunch.com/2017/03/31/spacexs-first-falcon-heavy-launch-could-attempt-upper-stage-recovery/

    How can it be a viable proposition for them and not SLS?


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  • #12
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,657 Mod ✭✭✭✭Capt'n Midnight


    josip wrote: »
    How can it be a viable proposition for them and not SLS?
    SLS is old tech using off the shelf 1970's leftovers from the Shuttle.

    The first stage SRB's are cheap and chearful, not worth refurbishing re-manufacturing.

    The expensive bits are the engines and turbopumps. Blue Origin is planning to recover just them on it's stages. But on SLS , like the shuttle the engine and fuel tank will be taken to orbital velocity, so a full re-entry would be needed with all the extra weight that would take.


  • #13
    Stan27
    Registered Users Posts: 528 ✭✭✭Stan27


    how far away are blue origin from launching satiates?, or are they concentrating on the tourism sector first, getting people to sub orbit.


  • #14
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,657 Mod ✭✭✭✭Capt'n Midnight


    Stan27 wrote: »
    how far away are blue origin from launching satiates?, or are they concentrating on the tourism sector first, getting people to sub orbit.
    If they get the BE-4 engine working then they will have re-invented the wheel. But it needs re-inventing because at present ULA is relying on Russian engines.

    https://www.blueorigin.com/be4

    The main advantage of Methane is that it doesn't leave residues in the engines, which is handy for reuse. It needs larger tanks so not much better than super chilled kerosene and cyrogenics are way more difficult to handle.

    Ignore any waffle about methane self pressurising as you need much stronger tanks which adds weight. Also self pressure means lower engine pressure which translates into lower efficiency. Yes it's good if you want cheap and reliable, especially in orbit when don't have an atmosphere to push against. But not so good when you want extract tax payers dollars.


  • #15
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,657 Mod ✭✭✭✭Capt'n Midnight


    The higher up you go the thinner the air gets. By the time you reach 100Km an aeroplane would need to travel at orbital velocity to gain enough lift.

    So 100Km is the edge of space, if you are travelling at 27,000 Km/hr.


  • #16
    Stan27
    Registered Users Posts: 528 ✭✭✭Stan27


    So it's expected the the BE-4 engine will out perform both space x's merlin and raptor engines?


  • #17
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,657 Mod ✭✭✭✭Capt'n Midnight


    Stan27 wrote: »
    So it's expected the the BE-4 engine will out perform both space x's merlin and raptor engines?
    Depends on what metric you use.

    thrust
    specific impulse
    all up weight , including tankage
    cost

    And then there's the Total Cost Of Ownership,

    IIRC Space-X rocket uses something like $200,000 of propellants. Easy to handle fuel and Liquid Oxygen is something you can order by the truckload, even here. So if they made a rocket that needed twice as much fuel but was a few % cheaper it would probably be worth looking at.


  • #18
    Hmmzis
    Registered Users Posts: 2,004 ✭✭✭Hmmzis


    Just a clarification about tank pressurization. There is stored gas type pressurization that is comonly done with highly compressed He in storage tanks on the vehicle. Falcon 9 uses COPV bottles (Compressive Overwrap Pressure Vessel) immersed in the LOX tank to get more He in the same volume. Saturn 5 and Ariane use Ti bottles outside the tanks in the interstage area.
    The other is autogenous pressurization where the propellant is used to pressurize the main tank by heating it up in a heat exchanger on the engines producing a hot gas that then gets fed back into the main tank. For both, methane and LOX, there would have to be separate heat exchangers as you do not want to mix hot CH4 with LOX and hot O2 with liquid CH4 (that's better left to the comustion chamber in the engines). This pressure is only high enough to keep the tanks from collapsing and providing enough head pressure for the turbopumps (very important to avoid cavitation). For Falcon 9 that pressure is about 3 bar. The actual pressure for the combustion chamber is provided by the turbopumps, they can go to insane pressures. The Merlin 1D is quite benign at around 97.2 bar, the Space Shuttle Main Engines were a bit toastier at 204 bar. The Raptor is a different beast altogether with the turbos pumping up to a whopping 303.36 bar.

    What Captn' Midnight is refering to is pressure fed engine design in rockets. This design is very simple as it avoids all the turbo machinery that makes liquid rocket engines so complex and expensive. The fuel and oxidizer tanks in this design are basically high pressure bottles and the fuel and oxidizer gets fed into the combustion chamber by this pressure alone. It's simple but works only for small rockets and is quite inefficient (high weight for tanks, not that much pressure at all, poor ISP due to ever decreasing chamber pressure).


  • #19
    namloc1980
    Registered Users Posts: 18,058 ✭✭✭✭namloc1980


    Launch tonight of Inmarsat 5 F4 at 19.21 EDT (00.21 Irish time). This is the heaviest payload yet for Falcon 9 and therefore no first stage recovery - using the expendable version.


  • #20
    Thargor
    Registered Users Posts: 17,863 ✭✭✭✭Thargor


    SpaceX launch in 2 minutes:



  • #21
    Stan27
    Registered Users Posts: 528 ✭✭✭Stan27


    Thargor wrote: »
    SpaceX launch in 2 minutes:


    I wonder when the falcon heavy is operational, will a payload like this be done on the heavy, so they can save the boosters, rather than having it expendable.


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  • #22
    Thargor
    Registered Users Posts: 17,863 ✭✭✭✭Thargor


    Id say thats one of its main selling points.

    Imagine when a heavy is launched, we'll be seeing 2 boosters come back and land at Cape Canaveral and the heavy landing on the barge at sea, should be entertaining!


  • #23
    Stan27
    Registered Users Posts: 528 ✭✭✭Stan27


    Thargor wrote: »
    Id say thats one of its main selling points.

    Imagine when a heavy is launched, we'll be seeing 2 boosters come back and land at Cape Canaveral and the heavy landing on the barge at sea, should be entertaining!

    It will be awesome, any idea when a date will be given for its launch ?


  • #24
    namloc1980
    Registered Users Posts: 18,058 ✭✭✭✭namloc1980


    Stan27 wrote: »
    It will be awesome, any idea when a date will be given for its launch ?

    Sept / Oct is the expectation.

    The next Spacex resupply mission to the ISS is next Thursday 1st June. Launch at 21.55 Irish time means it may be visible from Ireland about 20 mins after launch as it chases down the ISS in its 51.6 degree orbit.


  • #25
    Beeker
    Moderators, Science, Health & Environment Moderators Posts: 3,643 Mod ✭✭✭✭Beeker


    namloc1980 wrote: »
    Sept / Oct is the expectation.

    The next Spacex resupply mission to the ISS is next Thursday 1st June. Launch at 21.55 Irish time means it may be visible from Ireland about 20 mins after launch as it chases down the ISS in its 51.6 degree orbit.

    That's 2155 UTC so 2255 Irish time


  • #26
    Thargor
    Registered Users Posts: 17,863 ✭✭✭✭Thargor


    Anyone know if it will actually be visible?


  • #27
    namloc1980
    Registered Users Posts: 18,058 ✭✭✭✭namloc1980


    Thargor wrote: »
    Anyone know if it will actually be visible?

    Yeah should be visible about 15-20 minutes after launch - weather dependent of course. I remember seeing CRS-6 in 2015. Could easily make out the Dragon, second stage and two payload fairings.


  • #28
    Alcoheda
    Registered Users Posts: 246 ✭✭Alcoheda


    stupid question but which direction do I look and does anyone know how high from the horizon?


  • #29
    Beeker
    Moderators, Science, Health & Environment Moderators Posts: 3,643 Mod ✭✭✭✭Beeker


    Alcoheda wrote: »
    stupid question but which direction do I look and does anyone know how high from the horizon?

    If the weather is nice to us and the clouds make way you should see it moving from the west to the east/south east passing almost overhead.


  • #30
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,657 Mod ✭✭✭✭Capt'n Midnight


    http://www.spacex.com/webcast live in under 3 hours
    The instantaneous launch window is on Thursday, June 1 at 5:55 p.m. EDT or 21:55 UTC, with a backup launch opportunity on Saturday, June 3 at 5:07 p.m. EDT or 21:07 UTC



    Bonus Flight - 00:45 to 1:45 Irish time.
    Ariane Flight VA237 with ViaSat-2 and EUTELSAT 172B
    http://www.arianespace.com/mission/ariane-flight-va237/


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  • #31
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,657 Mod ✭✭✭✭Capt'n Midnight


    http://met.ie/latest/rainfall_radar.asp
    http://met.ie/forecasts/3hour.asp :(


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