Author Topic: SpaceX Eastern Range Landing Facilities  (Read 217435 times)

Offline Comga

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Re: SpaceX Eastern Range Landing Facilities
« Reply #80 on: 01/23/2015 03:15 PM »
Parabolic Arc reports that a draft environmental report supports the new facility. While clearing out several acres of brush will temporarily disrupt some wildlife, they'll offset this with fresh growth over the next 5 years.

http://www.parabolicarc.com/2015/01/12/draft-environmental-report-backs-spacex-landing-facility-cape-canaveral/

One item in there is: "The assessment also recommended a number of other mitigation measures, including limiting construction activities during the scrub-jay’s nesting season."

The Florida Wildlife Service lists the Florida scrub jay as "threatened" and says "the breeding season .... runs from March through June".  That could mean "limiting" construction throughout the spring.

Anyone have any history of other seasonal restrictions at other Cape construction sites?
Down the coast there are restrictions on lights near the beach after sundown to protect sea turtles.  I didn't see that mentioned here.

Are there other such restrictions?

edit: Factual error corrected
« Last Edit: 01/23/2015 03:23 PM by Comga »
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline mvpel

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Re: SpaceX Eastern Range Landing Facilities
« Reply #81 on: 01/24/2015 06:57 PM »
What if "hard landing" would render main pad inoperable for the next several launches? Contingency pad  could be used as a min pad until main is back in the operation...

I think the "contingency" which they're concerned about is not a hard landing, but future approval of a future request for permission to land more than one stage at a time there, using the term in the meaning of "dependence on ... the fulfillment of a condition." It's certainly better to get the environmental red tape out of the way now rather than later.
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Offline meekGee

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Re: SpaceX Eastern Range Landing Facilities
« Reply #82 on: 01/25/2015 02:51 AM »
Here's another thought:

The center pad might be more than just a "training pad".

Maybe the center pad is the future "crash pad".  Once SpaceX is confident, incoming stages will aim at the center pad, and then divert to any of the other four pads once the engine starts up.
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Online speedevil

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Re: SpaceX Eastern Range Landing Facilities
« Reply #83 on: 01/26/2015 09:11 AM »
Here's another thought:

The center pad might be more than just a "training pad".

Maybe the center pad is the future "crash pad".  Once SpaceX is confident, incoming stages will aim at the center pad, and then divert to any of the other four pads once the engine starts up.

The centre pad is where they fit the trampoline.

Offline Burninate

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Re: SpaceX Eastern Range Landing Facilities
« Reply #84 on: 01/26/2015 07:41 PM »
What if "hard landing" would render main pad inoperable for the next several launches? Contingency pad  could be used as a min pad until main is back in the operation...

I think the "contingency" which they're concerned about is not a hard landing, but future approval of a future request for permission to land more than one stage at a time there, using the term in the meaning of "dependence on ... the fulfillment of a condition." It's certainly better to get the environmental red tape out of the way now rather than later.
I don't.  These are very closely spaced.  You would not want to send rockets down simultaneously at this distance from each other.  I think an unexpected low-altitude wind change or misguided estimate which pushes the rocket off-course by ~100m+ in the last few thousand meters of descent is what they're protecting against.  RTLS is very useful for Falcon Heavy boosters, and mildly useful for Falcon 9R, while Falcon Heavy centercore will always need a barge/ship/island LZ.  I think Falcon Heavy will routinely land boosters RTLS-style on two separate pads, once it gets clearance - and each pad will have these four contingency pads positioned nearby.

Missed this:  "There are no plans to utilize the contingency pads in order to enable landing multiple stages at LC-13 during a single landing event."
« Last Edit: 01/26/2015 07:44 PM by Burninate »

Offline meekGee

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Re: SpaceX Eastern Range Landing Facilities
« Reply #85 on: 01/26/2015 09:30 PM »



Missed this:  "There are no plans to utilize the contingency pads in order to enable landing multiple stages at LC-13 during a single landing event."

This is the bit that has me stumped.

Using the 4 pads as alternate landing pads in case of an anomaly does not make sense.

We don't know of an additional pad for the other side core. Why have a plan for just one?

It just does not add up.
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Offline Space OurSoul

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Re: SpaceX Eastern Range Landing Facilities
« Reply #86 on: 01/26/2015 09:59 PM »
Maybe the key phrase is "during a single landing event".

If there's a stage sitting on the main pad after a launch from '40, they can still land a stage that launched from '39A on the contingency pad (or vice-versa).

Just a guess. Doesn't make much sense to me either.

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Online deruch

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Re: SpaceX Eastern Range Landing Facilities
« Reply #87 on: 01/27/2015 02:46 AM »
An alternate hypothesis.  Maybe SpaceX doesn't plan to use the "contingency" pads at all.  They might not have wanted them in the first place and there's no guarantee that they will ever be built.  At this point in time, we don't know what regulatory oversight has driven the design of the landing facility.  [speculation] Say, for example, SpaceX only thinks they need the main pad for landing but either Range Safety or the FAA is telling them they need to have some "contingency" pads.  SpaceX hasn't yet been able to conclusively demonstrate that they are able to fully control a returning stage all the way to touchdown.  So even though they don't think they need them they can't really prove it.  Not yet anyways.  They want to move forward with the landing facility plans and don't want to wait until they can fully demonstrate their capabilities.  So they've added them to the Environmental Impact study.  If they are forced to keep them, OK they've done the paperwork.  If they can show that the extra pads aren't necessary, maybe the regulatory agencies won't insist on them being built.  If they decided later that they do actually want them, they won't have to do additional studies first. [/speculation]

I don't believe the above hypothesis is the case, but it's certainly possible.  And it could explain the apparent disconnect in the logic.  We haven't seen anything beyond the EIS.  What actually gets built on large projects is often different, at least somewhat, from the original plans used for study.  Until we start to see actual construction we may not fully know.  Unless SpaceX releases different drawings at some point.
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Offline meekGee

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Re: SpaceX Eastern Range Landing Facilities
« Reply #88 on: 01/27/2015 03:13 AM »
An alternate hypothesis.  Maybe SpaceX doesn't plan to use the "contingency" pads at all.  They might not have wanted them in the first place and there's no guarantee that they will ever be built.  At this point in time, we don't know what regulatory oversight has driven the design of the landing facility.  [speculation] Say, for example, SpaceX only thinks they need the main pad for landing but either Range Safety or the FAA is telling them they need to have some "contingency" pads.  SpaceX hasn't yet been able to conclusively demonstrate that they are able to fully control a returning stage all the way to touchdown.  So even though they don't think they need them they can't really prove it.  Not yet anyways.  They want to move forward with the landing facility plans and don't want to wait until they can fully demonstrate their capabilities.  So they've added them to the Environmental Impact study.  If they are forced to keep them, OK they've done the paperwork.  If they can show that the extra pads aren't necessary, maybe the regulatory agencies won't insist on them being built.  If they decided later that they do actually want them, they won't have to do additional studies first. [/speculation]

I don't believe the above hypothesis is the case, but it's certainly possible.  And it could explain the apparent disconnect in the logic.  We haven't seen anything beyond the EIS.  What actually gets built on large projects is often different, at least somewhat, from the original plans used for study.  Until we start to see actual construction we may not fully know.  Unless SpaceX releases different drawings at some point.

Interesting.

If an external body insisted on them, then yes, logic may not have been in command....

But still.  If a stage coming down is too sick to hit the large pad, who says 150 m (or whatever they used) is the right distance to place the smaller pads at?  what if it is "300 m sick"? 

It will be interesting to see how the west coast landing pad is shaping up.

And some time this year I hope  there will be some groundwork at Boca Chica to look at.

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Offline sdsds

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Re: SpaceX Eastern Range Landing Facilities
« Reply #89 on: 01/27/2015 06:27 AM »
If a stage coming down is too sick to hit the large pad, who says 150 m (or whatever they used) is the right distance to place the smaller pads at?  what if it is "300 m sick"? 

That's when you take some action that leads to a Rapidly Increased Ballistic Coefficient (RIBC) of the incoming mass so it ends up in the Atlantic.

I think the presence of contingency pads let them continue flying a healthy vehicle when it is still quite some distance out, and maybe a little outside its nominal corridor, without having the RSO send the RIBC signal.

;)
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Online guckyfan

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Re: SpaceX Eastern Range Landing Facilities
« Reply #90 on: 01/27/2015 07:00 AM »
Actually this kind of arrangement is what I thought of early on about possible landing pads. Until I discarded the idea as completely unnecessary. 8)

Offline dglow

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Re: SpaceX Eastern Range Landing Facilities
« Reply #91 on: 01/27/2015 03:04 PM »
If four little pads are truly for contingency, why not extend the large gravel circle to reach all of them? It doesn't add up.

One possibility: the gravel is for returning capsules, or contingencies thereof. Parachutists often target shallow gravel patches on their return.

Offline sghill

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Re: SpaceX Eastern Range Landing Facilities
« Reply #92 on: 01/27/2015 03:30 PM »
If four little pads are truly for contingency, why not extend the large gravel circle to reach all of them? It doesn't add up.

Because it's environmentally sensitive land.  They want have to disturb as little as possible.

[soapbox] Folks, RTFM (pretty please).  The Environmental Assessment for the pad has almost every answer to serious questions raised on this thread- if you read enough of it.  It's not enough to take snippets like this:

"The contingency pads would only be utilized in order to enable the safe landing of a single vehicle should last-second navigation and landing diversion be required [e.g. a wind gust IMHO]. There are no plans to utilize the contingency pads in order to enable landing multiple stages at LC-13 during a single landing event. "

[/soapbox]

:)
« Last Edit: 01/27/2015 03:31 PM by sghill »
Bring the thunder Elon!

Offline Doesitfloat

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Re: SpaceX Eastern Range Landing Facilities
« Reply #93 on: 01/27/2015 03:37 PM »
If four little pads are truly for contingency, why not extend the large gravel circle to reach all of them? It doesn't add up.

One possibility: the gravel is for returning capsules, or contingencies thereof. Parachutists often target shallow gravel patches on their return.

"Gravel Patches"- When I missed the airport I aim for pool parties and BBQ's. 
We all have our priorities.  ;)

Offline Confusador

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Re: SpaceX Eastern Range Landing Facilities
« Reply #94 on: 01/27/2015 03:42 PM »

[soapbox] Folks, RTFM (pretty please).  The Environmental Assessment for the pad has almost every answer to serious questions raised on this thread- if you read enough of it.  It's not enough to take snippets like this:

"The contingency pads would only be utilized in order to enable the safe landing of a single vehicle should last-second navigation and landing diversion be required[e.g. a wind gust IMHO]. There are no plans to utilize the contingency pads in order to enable landing multiple stages at LC-13 during a single landing event. "

[/soapbox]

:)

The soapbox there is a little unwarranted, as if you'll read the thread you'll see that the explanation given is well known.  The discussion is about how to make the explanations make sense.

I'm personally of the opinion that they don't have any plan for FH boosters yet, because they're planning to see how operations work at this pad before designing the next one.  Though I still haven't seen any explanation that makes the number of contingency pads make sense.  (I'm willing to admit they may not be sensible, they may be intended as overkill in order to win approval.  Not convinced of that yet, either.)

Offline Lobo

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Re: SpaceX Eastern Range Landing Facilities
« Reply #95 on: 01/27/2015 03:48 PM »
Maybe the divert pads are for off-nominal landings or unexpected ground winds.

They could be for that.

They could also part of "future" plans, depending on how reliable single booster recovery is, and after they negotiate with USAF and work through whatever permits and environmental concerns there will be to bring 2 or 3 cores back all at once.  Maybe it's sort of a "one with an option for three later...depending on how things go" situation?

If you look at the two contingency pads just to the North and South of the main pad, sure seems like three cores could come back and land at those 3 pads, with the other two in case one of the 3 cores has issues.  There's two alternative pads do divert to.  If landing all 3 at once, thing will be pretty hectic.  You don't want their trajectories running them too close to each other.

If they have -no- plans to ever land more than 1 core here, 4 alternative pads seems a bit over kill.  But if landing 2 or 3 cores, that leaves 3 or 2 alternate pads available...which seems like a much more reasonable number.

Offline Lobo

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Re: SpaceX Eastern Range Landing Facilities
« Reply #96 on: 01/27/2015 03:59 PM »
I'm also having trouble imagining a wind gust that would divert the stage to that degree --- or a fuel issue that would cause an abort to a pad *further* from the coast.

Perhaps the real issue is political: in order to expedite the application, the first EIS is explicitly only for a single returning core, even though they manage to build 5 (!) pads by using the "contingency" fig leaf.  (And perhaps this is even technically the truth if they have ALHAT-style targetting of all five----even though no reasonable combination of conditions will actually cause a divert.)

And then once they have established single-core landing operations, and everyone is happy with their safety, environmental soundness, etc, they can apply for a new EIS expanding their operations to two or three pads.  This would mitigate risk, as they wouldn't be endangering their existing one-pad operations if this new application runs into trouble.

That is, when they write, "There are no plans to utilize the contingency pads in order to enable landing multiple stages at LC-13 during a single landing event," the reader is meant to insert "For the purposes of this initial EIS" at the beginning.

Alternatively, their pivot to barges and the relative risk assessments might mean they plan to perform at least the first F9H core recoveries at sea, and at the moment they think that's a reasonable plan for the five-year span of the initial license.  Again, reserving the right to pivot via a new EIS later if the ASDSes run into issues.

@this.

I've heard it estimated that FH should be able to get 6-7mt to GTO while returning all three cores to the launch site.   More if they expend the central core or land it on the barge downrange....but there really aren't payloads that need more than 6-7mt to GTO out there in the near future.  So that configuration may not be needed for awhile.  There are unlikely any payloads in the next several years that would need FH to expend the boosters.  They should almost always be returning to the launch site.  Which means there will be -2- cores at least for every FH launch, and more likely all three for some time.  Unless SpaceX just wants to be dumping those in the ocean...which will make FH much more expensive to fly...they really need the ability to land 3 cores back at the launch site.  And sooner rather than later as FH should fly this year.  They can use the barge just off shore to recover one of the 3 cores, but they'll be wanting to land at least 2 cores at LC-13 within the first few FH launches I imagine.  Otherwise they are splashing cores for no reason.

With this LC design, it becomes pretty much immediately capable of recovering all 3 cores on 3 of the 5 pads with two alternate pads and a lot of level compressed soil/sand to cover contingencies.  All they'll need to do is an expanded EIS and probably some talks with USAF, and they'll be ready to roll.

Offline watermod

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Re: SpaceX Eastern Range Landing Facilities
« Reply #97 on: 01/27/2015 04:24 PM »
Parabolic Arc reports that a draft environmental report supports the new facility. While clearing out several acres of brush will temporarily disrupt some wildlife, they'll offset this with fresh growth over the next 5 years.

http://www.parabolicarc.com/2015/01/12/draft-environmental-report-backs-spacex-landing-facility-cape-canaveral/

One item in there is: "The assessment also recommended a number of other mitigation measures, including limiting construction activities during the scrub-jay’s nesting season."

The Florida Wildlife Service lists the Florida scrub jay as "threatened" and says "the breeding season .... runs from March through June".  That could mean "limiting" construction throughout the spring.

Anyone have any history of other seasonal restrictions at other Cape construction sites?
Down the coast there are restrictions on lights near the beach after sundown to protect sea turtles.  I didn't see that mentioned here.

Are there other such restrictions?

edit: Factual error corrected

So... the tough question:  "Will a first stage be permitted to land when it is the scrub-jay’s nesting season?"

Offline JamesH

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Re: SpaceX Eastern Range Landing Facilities
« Reply #98 on: 01/27/2015 04:28 PM »
They are permitted to take off. Is landing any different (to the scrub Jay)?

Offline Lobo

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Re: SpaceX Eastern Range Landing Facilities
« Reply #99 on: 01/27/2015 04:37 PM »
Aha! I think I see what's missing. How about...

– Center pad is the 'proving pad' for F9 booster landings
– After n successful bullseyes, boosters transition to the adjacent pads
– Center pad becomes the landing site for returning Dragons

Could be, but Dragons returning to Florida will be coming from the West, so there's not really any need to land them there like there is the cores.
Myself, I'd expect Dragons to return to either EAFB or VAFB/SLC-4 (if they want to prevent too much land flyover since DV2 can't actually "fly" like the Shuttle or DC) or the SLF at KSC if they are ok with it flying over populated land.  Don't know if that will be an issue or not.

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