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/
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...
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.
Quote from: schaban on 01/12/2015 07:28 pmWhat 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.
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."
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.
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"?
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.
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.
[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]
Maybe the divert pads are for off-nominal landings or unexpected ground winds.
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.
Quote from: MattMason on 01/13/2015 01:25 pmParabolic 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
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