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SpaceX Plans to Land Next Falcon 9 on Solid Ground

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Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#21

Does this mean they'll be launching from another facility? Right now, the trajectory goes over to the sea, and bringing the first stage back to dry land is expensive. They'd have to launch far away from the east coast.

Yes, this launch will take place from Vandenberg Air Force Base in California (according to http://spacexstats.com/upcoming.php )

[deleted]

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#22
post #6

Earlier quoted context omitted.

It is my understanding that the eventual goal has always been to land where they takeoff/launch from.

I never read anything that pointed towards that objective. Note that the first stage gets a lot of horizontal velocity, so bringing it back to the launch pad is expensive (fuel-wise). It is better to just cancel out the horizontal vector, follow a parabolic trajectory and land east of the launch pad.

Return to Launch Site (RTLS) has been the goal from day one. Yes, it's expensive in terms of payload (about 30%), but SpaceX thinks it's worth it. The cost to fill all tanks is ~$200,000, which pales in comparison to everything else. They will land every rocket they can (determined by how much ΔV the payload requires). I'm quite sure that reusable Falcon Heavy launches will be cheaper than expendable Falcon 9 launches, which incentivizes customers with payloads on the margin to choose the Heavy, which allows SpaceX to return at least 2 cores to the launch site.

(Neat little aside: launches from Florida and Texas can also take slight advantage of the earth rotating beneath the rocket in the direction they want it to.)

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#23
post #4

Earlier quoted context omitted.

Hmm, I read it as intended - that the next time they will try to land will be on land. This page is quite a useful (although not 100% accurate) summary of the near-future of SpaceX: http://spacexstats.com/upcoming.php Certainly interesting that the FCA are willing to try a land-launch before getting a successful landing on the barge.

I think they've ruled out the barge landing at this point. Seems like even with the stabilization, there is still too much movement. I dont see any reason they couldn't bring it back over water onto a landing pad. It should be really easy to keep the landing pad clear.

Almost certainly not. They're still working on building a second drone ship on the west coast. Even after they accomplish landings on land, there will still be a need for barge landings in two scenarios: Falcon 9 launches with payloads large enough to prohibit a full boostback burn, and more importantly, Falcon Heavy launches. On the Heavy, the two strap-on boosters will be able to make it back to land but the core stage will be much further downrange and moving much faster, almost certainly necessitating an ocean landing.

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#24
post #8

I think now that they have proven they can 'hit the hole', almost spot on, they'll be able to get approval to go for a try on cleared land space. It sounds like to me, landing on land would be ideal; less expensive and less risk with stabilization and rough waters.

They need to be able to stabilize the rocket's landing in all sorts of conditions if they want to have any hope of landing it on another planet. It's not like interplanetary launches will be able to schedule launches to choose optimal weather conditions for the landing. Maybe, if they're lucky, they'll be able to orbit briefly to avoid bad weather at the landing site, but moderate winds and wind gusts are going to be a problem. If it's impossible to reliably land under those conditions, the whole idea is flawed for the purposes of interplanetary flight. You can't have rockets going to Mars, and only have 50% or 75% surviving for relaunch. That's not the kind of cost reduction that will make interplanetary travel and resupply feasible.

It would obviously help with LEO launch costs, though, or any return landings on Earth. Even if rocket stages are only recovered some of the time, and not reliably, that's a significant cost savings and well worth doing. It's just that Musk is so intent on interplanetary travel driving all this technology. If it's only for cost savings for Earth landings, a parachute system or a specially designed (more accommodating) landing complex/barge could work too, right?

> (paraphrasing multiple comments) "but this is to re-land rocket stages on Earth"

Here's an interview where he specifically talks about his long term goal of landing rocket stages on other planets. He says parachutes negatively affect reusability, I'm not sure how much of that is potential damage or off-site landing and how much is the necessity to reinstall a parachute for the next launch. The point here is that he is clearly not thinking only of Earth landings in developing this technology. I think some sort of assisted landing or more developed landing site could increase chance of recovery and reusability for Earth landings, decreasing total launch costs for Earth orbit missions, at the cost of not being applicable to landings on other planets.

[1] https://www.youtube.com/watch?v=SOpmaLY9XdI?t=11m30s

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#25
post #6

Earlier quoted context omitted.

It is my understanding that the eventual goal has always been to land where they takeoff/launch from.

I never read anything that pointed towards that objective. Note that the first stage gets a lot of horizontal velocity, so bringing it back to the launch pad is expensive (fuel-wise). It is better to just cancel out the horizontal vector, follow a parabolic trajectory and land east of the launch pad.

I think they want to return to a launch site, just not neccessarily the site that launched the rocket in the first place. AFAIK that's why they want to have multiple sites.

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#26
> "Just purely the boat moving, even in a low sea state, it's hard to imagine that vehicle is going to stay vertical," Shotwell said. "That vehicle is big and tall, compared to the itty-bity-greater-than-a-football-field-size ship."

Is this a new development? This contradicts both a lot of things I read over the Internet (granted, those were not official SpaceX statements) and the apparently still ongoing plans to build a second barge.

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#27
post #8

I think now that they have proven they can 'hit the hole', almost spot on, they'll be able to get approval to go for a try on cleared land space. It sounds like to me, landing on land would be ideal; less expensive and less risk with stabilization and rough waters.

They need to be able to stabilize the rocket's landing in all sorts of conditions if they want to have any hope of landing it on another planet. It's not like interplanetary launches will be able to schedule launches to choose optimal weather conditions for the landing. Maybe, if they're lucky, they'll be able to orbit briefly to avoid bad weather at the landing site, but moderate winds and wind gusts are going to be…

At the same time, getting to a point where SpaceX has a 10X pricing advantage over there competitors could have a nice effect on their R&D budget for solving problems that may not be immediately applicable on Earth.

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#28
post #7

I don't think they can completely give up on the barge though. As I understand it they'll always need barge landings for the Falcon Heavy core? Maybe they're just itching to get a success on their pelt.

Why will they always need the barge for the Falcon Heavy core? I think they would be more likely to need it for a second stage than the Heavy's core, because SSECO occurs very far down range, and at such a high speed that the rocket cannot make it back to the launch pad without a great deal of fuel.

Alternatively, they could be planning to launch from Texas, and recover some stage(s) in Florida.

*edit: in another comment on this discussion, kllrohg mentioned that SpaceX's stated intent has been to land all stages back at the launch site.

https://news.ycombinator.com/item?id=9388762

http://www.space.com/13140-spacex-private-reusable-rocket-el....

Re: SpaceX Plans to Land Next Falcon 9 on Solid Ground

#29
post #7

I don't think they can completely give up on the barge though. As I understand it they'll always need barge landings for the Falcon Heavy core? Maybe they're just itching to get a success on their pelt.

I agree, as others have said the dynamics of a barge is a necessary challenge to prove the technology. But they need some more positive press, maybe a gif that doesn't end in an explosion hehe.

On a side note the colloquialism 'success on their pelt' is totally new to me, I've always heard it as 'success under their belt'.

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