Author Topic: Pad 39A - Transition to SpaceX Falcon Heavy debut - Thread 1  (Read 188054 times)

Online guckyfan

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So is there a large enough location at the cape to facilitate the return of 3 F9s at the same time?

As was said above, the center core will not have enough residual propellant to do a boostback to land. They will either let it sink or maybe try to land on the barge.

Not true. Return of all three cores reduces the payload a lot. But I understand they can deliver at least 7t to GTO which will enable them to launch even the heaviest Com-Sats while expending only the upper stage. Downrange recovery is considered for payloads heavier than that.


Offline newpylong

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Building over the crawlerway - interesting. Must really not be any room.
« Last Edit: 11/19/2014 05:50 PM by newpylong »

Offline oiorionsbelt

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Building over the crawlerway - interesting. Must really not be any room.
or the crawler way is the easiest, cheapest place to build because it's already a pretty good foundation and the EPA doesn't need to be involved.

Offline rpapo

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Building over the crawlerway - interesting. Must really not be any room.
or the crawler way is the easiest, cheapest place to build because it's already a pretty good foundation and the EPA doesn't need to be involved.
Nor all that stuff involving archaeology either.  Remember the document we saw a few months back regarding the proposed vertical processing facility for LC40?
An Apollo fanboy . . . fifty years ago.

Online MP99



So is there a large enough location at the cape to facilitate the return of 3 F9s at the same time?

As was said above, the center core will not have enough residual propellant to do a boostback to land. They will either let it sink or maybe try to land on the barge.

So there will never be 3 stages returning to land from one launch. 2 at most. The KSC/Cape master plan map shows a proposed generic landing area near the shore north of the launch complexes, but there aren't any details yet.

Once they get crossfeed operational, that will make RTLS of the boosters quite a bit easier (they will stage earlier / slower / lower, so the recovery penalty is smaller).

Barge for the core only, much further downrange. Reminder that for a Boca Chica launch the core would overshoot Florida. (Which I mention only to highlight just how far downrange we're talking about - not a topic for discussion on this thread).

Cheers, Martin

Offline cscott

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Building over the crawlerway - interesting. Must really not be any room.

The environmental assessment report for Pad 39A (thank @sghill for that!), showed the five different placements considered.

Offline Kabloona

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So is there a large enough location at the cape to facilitate the return of 3 F9s at the same time?

As was said above, the center core will not have enough residual propellant to do a boostback to land. They will either let it sink or maybe try to land on the barge.

Not true. Return of all three cores reduces the payload a lot. But I understand they can deliver at least 7t to GTO which will enable them to launch even the heaviest Com-Sats while expending only the upper stage. Downrange recovery is considered for payloads heavier than that.

I stand corrected.

By the way, in answer to the original question, LC-13 is apparently the prime candidate for landing site at the Cape. Presumably SpaceX is looking down the road to simultaneous multiple stage returns and planning accordingly.

http://www.nasaspaceflight.com/2014/11/crs-5-dragon-mission-iss-evaluating-december-target/
« Last Edit: 11/20/2014 02:30 PM by Kabloona »

Offline rpapo

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Presumably SpaceX is looking down the road to simultaneous multiple stage returns and planning accordingly.
The two landing pads at Vandenberg will be very close to each other, and there is a lot more space available at LC-13.  They should have no trouble building two 100m2 concrete pads (each twice the size of the barge) a few hundred yards apart from each other.
« Last Edit: 11/20/2014 04:24 PM by rpapo »
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Offline Beittil

Landing pads would need to be bigger than 100m2 though, because at that size they wouldn't even cover the leg span of the returning stage (which is 18 meters I believe?). 100m2 = 10 by 10 meters.

The current pad at McGregor is (I believe) 30 by 30 meters. This comes down to 900m2, still something that you could easily fit twice over at LC13 it seems to be, but quite a bit more area than you project here :)

Offline Kabloona

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Landing pads would need to be bigger than 100m2 though, because at that size they wouldn't even cover the leg span of the returning stage (which is 18 meters I believe?). 100m2 = 10 by 10 meters.

He means 100 m x 100 m, which is about twice the size of the barge SpaceX is building for ocean landings, as he mentioned.
« Last Edit: 11/20/2014 03:47 PM by Kabloona »

Offline rpapo

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Landing pads would need to be bigger than 100m2 though, because at that size they wouldn't even cover the leg span of the returning stage (which is 18 meters I believe?). 100m2 = 10 by 10 meters.

He means 100 m x 100 m, which is about twice the size of the barge SpaceX is building for ocean landings, as he mentioned.
I've fixed my earlier post.  I hadn't noticed the "superscript" button here before.  Anyway, 100m squared is actually far larger than what they've been using for Grasshopper, and in fact almost as wide as the widest airport runway in the world (a Russian one).
« Last Edit: 11/20/2014 04:30 PM by rpapo »
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Offline cscott

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Landing pads would need to be bigger than 100m2 though, because at that size they wouldn't even cover the leg span of the returning stage (which is 18 meters I believe?). 100m2 = 10 by 10 meters.

He means 100 m x 100 m, which is about twice the size of the barge SpaceX is building for ocean landings, as he mentioned.
I've fixed my earlier post.  I hadn't noticed the "superscript" button here before.  Anyway, 100m squared is actually far larger than what they've been using for Grasshopper, and in fact almost as wide as the widest airport runway in the world (a Russian one).

100m x 100m = 10,000m2.  It's best to say "100m on a side" if that's what you mean.

From Vandenberg I think people are misapprehending the implications: 2 pads under construction at Vandenberg plus consideration of an island downrange = return 2 side boosters to vandenberg, eventually return the center core to the downrange island (but not immediately, for a while it will be expendable).  Yes, those parameters are "not ideal" -- you could get greater throw capability by landing *everything* downrange, and the island is not "far enough" downrange to be optimal for the center.  But SpaceX has been clear that they are not aiming at theoretic optimality, they are aiming to reduce costs and decrease turnaround time.  So: return to landing site for the boosters, and return downrange only for the center core, and only as far downrange as the presence of terra firma and site availability permits.  At this point in time SpaceX is operating as if they believe that barge landing is not an economic/practical long-term solution.

Online AncientU

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Or at least that terra firma makes a better/cheaper 'barge' than one bobbing out in the pond...
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Offline brettreds2k

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Cant wait to see some pictures as they start building.
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Offline M_Puckett

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BTW, the first time in my life I ever saw the Atlantic was driving up on one of those two pads in a tour bus as a 12 year old in 1978 so I know how close they are to the ocean.

Offline edkyle99

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LC 39A Today.

Online ugordan

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Does this video by Florida Today show anything of interest? Apparently, the footage was taken today.

http://www.floridatoday.com/videos/news/local/2014/12/17/20547263/
« Last Edit: 12/17/2014 09:47 PM by ugordan »

Offline Ronsmytheiii

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Does this video by Florida Today show anything of interest? Apparently, the footage was taken today.

http://www.floridatoday.com/videos/news/local/2014/12/17/20547263/

First picture looks like the start of the strong back construction, second shows the crawlerway and hangar constructon

Offline Ronsmytheiii

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Less pizzaz, but looks like SpaceX has also removed the flame duct and is working on the flame trench wall.  This reminds me of the damage the pad took after STS-124, SpaceX probably wants to make sure its not an issue going forward:

http://www.nasaspaceflight.com/2008/07/investigation-confirms-vertical-debris-events-during-sts-124-launch/

Online darkenfast

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I have a feeling that they're only going to use half of it.  The inclined half that points back towards the existing crawler-way and eventual hanger would (I think), need to be filled so that the rails from the hangar can be built.  Of course, they could build a dual track-set bridging over the gap, but I think they'll want to avoid having a flame duct pointed at their hangar.  The other half handled the full load of the Shuttle SRBs, so a Falcon Heavy shouldn't be too much.

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