Author Topic: Pad 39A - Transition to SpaceX Falcon Heavy debut - Thread 2  (Read 156484 times)

Offline whitelancer64

I notice that the render shows the 8 hold downs for FH, but only 2 seem attached to the F9. There was discussion about the base plate having interchangeable configs to allow 4 hold downs on the F9. I wonder if the render is slightly wrong here.

I was wondering the same thing. Also, if the T/E is intended to go "full" horizontal at T=0 wont it need that center assembly shown in the red outline in the image below? That assembly, given its position in the exhaust deflection stream, is going to get a hell of a taste of the launch temps and pressures. If it is at that location at T0, what is securing it? What are the wheels made of (they look pneumatic/puffy)? 

Is it likely they won't have that assembly there during launch? If so, then the strong back will not go full horizontal after T0?

That's not supposed to be a flame trench, it's supposed to be a concrete ramp up to the pad. The South-facing flame trench has been filled in. The render is inaccurate in showing the South flame trench as still there.
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Offline clongton

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do I understand that article correctly that on holddown release the strongback will drop to the horizontal position?  If so, that should make for a (n already) visually interesting launch

Should be similar to the launch of the Soyuz. The vertical supports are held upright by the mass of the vehicle on the pad but as soon as Soyuz lifts off the supports they swing away and down pretty rapidly. F9/F9H have a completely different mechanism, but the visual effect should be similarly spectacular.
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Offline Chris_Pi

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I notice that the render shows the 8 hold downs for FH, but only 2 seem attached to the F9. There was discussion about the base plate having interchangeable configs to allow 4 hold downs on the F9. I wonder if the render is slightly wrong here.

There's big plugs that fill the extra space with a hold-down on each that can be installed for a F9. (In photos at Vandenberg) Probably not worth messing with for the render - Extra work and who's going to notice one way or the other?  ;D

Offline AS-503

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do I understand that article correctly that on holddown release the strongback will drop to the horizontal position?  If so, that should make for a (n already) visually interesting launch

Should be similar to the launch of the Soyuz. The vertical supports are held upright by the mass of the vehicle on the pad but as soon as Soyuz lifts off the supports they swing away and down pretty rapidly. F9/F9H have a completely different mechanism, but the visual effect should be similarly spectacular.

As mentioned above by star NSF forum member clongton, at T0 the large yellow counterweights shown in the images below act as a passive facilitator of the Soyuz mount retraction.

Online douglas100

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I notice that the render shows the 8 hold downs for FH, but only 2 seem attached to the F9. There was discussion about the base plate having interchangeable configs to allow 4 hold downs on the F9. I wonder if the render is slightly wrong here.

I was wondering the same thing. Also, if the T/E is intended to go "full" horizontal at T=0 wont it need that center assembly shown in the red outline in the image below? That assembly, given its position in the exhaust deflection stream, is going to get a hell of a taste of the launch temps and pressures. If it is at that location at T0, what is securing it? What are the wheels made of (they look pneumatic/puffy)? 

Is it likely they won't have that assembly there during launch? If so, then the strong back will not go full horizontal after T0?

I've read somewhere that SpaceX closed that part of the flame trench and during the launch exhaust flames/vapor would go only in one direction (away from the pad).

I think I read it in Chris article.

Yes, I think that's right. Also, the hydraulics which swing the TE vertical are on the south side as well. They can't be exposed to exhaust gasses any more than the bogey with its road wheels can.
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Offline ZachS09

do I understand that article correctly that on holddown release the strongback will drop to the horizontal position?  If so, that should make for a (n already) visually interesting launch

They did that for the Antares rocket launches.

Do you have a link to a picture of that? From what I remember Antares would just tilt it back a little further at liftoff. Maybe 45 degrees. Not horizontal...

I meant that the umbilical tower will start retracting immediately when Antares lifts off.
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Offline StuffOfInterest

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will falcon 9/Falcon heavy enter ( be assembled for launch)and exit to the pad from the same doors in the HIF?

That's where my confusion came from.  The text led me to believe that the strongback was going to retract all the way to horizontal before ignition.  That does bring up other ideas and/or questions.  How fast can the strongback retract?  As soon as there is launch commit and the holddowns release, can the strongback come down fast enough to make any meaningful difference on how much it gets cooked vs. just leaving it at the slightly back position?

EDIT: Reading the rest of the thread from after where I replied it looks like the retraction event has been the main topic of discussion.  Glad to know I'm not the only one a bit confused by this.  It will be interesting to see how it works out.
« Last Edit: 11/12/2015 01:23 PM by StuffOfInterest »

Offline darkenfast

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Somewhere in the previous thread, someone was told (while on a tour at KSC), that the strongback will quickly drop back after the vehicle has started moving and the various umbilicals are pulled loose from the rocket.  I think that is about all we know at present.  It should be a lot of fun to watch!

Offline cscott

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Remember that, as a liquid rocket, Falcon accelerates off the pad rather slowly.  Enough so that after every launch we have people dropping in here claiming there was some kind of anomaly.  The top of the strong back has quite a lever arm, so even a small angular change results in large horizontal displacement.  I'm sure there will be significant clearance by the time the stage rises its own length.
« Last Edit: 11/12/2015 01:18 PM by cscott »

Online philw1776

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The new Full Thrust Falcon will have a higher thrust/weight parameter even with heavier 2nd stage and will lift off faster
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Offline AndyX

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And the latest article to get us all up to speed:
http://www.nasaspaceflight.com/2015/11/spacex-conducts-rollout-39a-te/

The big SpaceX on the water tower is cool too! :)

Offline woods170

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And the latest article to get us all up to speed:
http://www.nasaspaceflight.com/2015/11/spacex-conducts-rollout-39a-te/

The big SpaceX on the water tower is cool too! :)

No matter what logo you stick to it, a water tower is uncool.

(doing a 'Jim' here)

Offline Zed_Noir

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The big SpaceX on the water tower is cool too! :)
No matter what logo you stick to it, a water tower is uncool.
...

Not if SpaceX put a countdown clock on it.  :)

Online edkyle99

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The new Full Thrust Falcon will have a higher thrust/weight parameter even with heavier 2nd stage and will lift off faster
A little higher, maybe, but not that much different (especially during the first second).  T/W will still likely be in the typical liquid rocket range (maybe 1.3-ish versus 1.2-ish previously).  Still more like an Atlas or an R-7 or a Proton than a Zenit.

 - Ed Kyle
« Last Edit: 11/13/2015 04:11 PM by edkyle99 »

Offline mme

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The new Full Thrust Falcon will have a higher thrust/weight parameter even with heavier 2nd stage and will lift off faster
A little higher, maybe, but not that much different (especially during the first second).  T/W will still likely be in the typical liquid rocket range (maybe 1.3-ish versus 1.2-ish previously).  Still more like an Atlas or an R-7 or a Proton than a Zenit.

 - Ed Kyle
I have a hypothesis that one reason people constantly think the F9 launch is slow is an illusion of sorts.  It is slow, but I think it "looks" even slower because it's such a tall rocket.  Same reason that a 747 looks like it is just hanging in the air on final approach even though it's going at least 130 mph.

To (almost) tie this thought into the thread, I wonder if the width of the F9H will effect that illusion.  I think all that matters is the length in the direction of travel so I doubt it.
Space is not Highlander.  There can, and will, be more than one.

Offline billh

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I have a hypothesis that one reason people constantly think the F9 launch is slow is an illusion of sorts.  It is slow, but I think it "looks" even slower because it's such a tall rocket.  Same reason that a 747 looks like it is just hanging in the air on final approach even though it's going at least 130 mph.
I think that's a good guess. I remember being in San Antonio and seeing a C-5A fly overhead after takeoff from Lackland AFB. It looked like it was going too slow to stay in the air and I had to keep reminding myself how big it really is.

Offline Lars-J

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This image is from an angle I had not seen before (from the NASA commercial crew presser) - but it looks like it is a few weeks old:

EDIT - found a better version of the image!
« Last Edit: 11/20/2015 09:07 PM by Chris Bergin »

Online Chris Bergin

Yeah, but as you say it's a nice angle. You can see the rail guides nicely in this!

Offline Johnnyhinbos

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What a missed opportunity Elon. Look at all that roof real estate - where's the solar city panels feeding a bank of powerwalls?
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Offline Lars-J

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What a missed opportunity Elon. Look at all that roof real estate - where's the solar city panels feeding a bank of powerwalls?

Look closer at the roof, maybe it is all panels.  ;D ;)

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